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1. Erratum: 'The NANOGrav 15 yr Data Set: Search for Signals from New Physics' (2023, ApJL 951 L11)

Author

Adeela Afzal, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Jose Juan Blanco-Pillado, Laura Blecha, Kimberly K. Boddy, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Belinda D. Cheeseboro, Siyuan Chen, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Curt J. Cutler, Megan E. DeCesar, Dallas DeGan, Paul B. Demorest, Heling Deng, Timothy Dolch, Brendan Drachler, Richard von Eckardstein, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Kyle A. Gersbach, Joseph Glaser, Deborah C. Good, Lydia Guertin, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Kristina Islo, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Vincent S. H. Lee, Natalia Lewandowska, Rafael R. Lino dos Santos, Tyson B. Littenberg, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Jonathan Nay, Priyamvada Natarajan, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Polina Petrov, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Tobias Schröder, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Peter Stratmann, Jerry P. Sun, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob Taylor, Stephen R. Taylor, Tanner Trickle, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sonali Verma, Sarah J. Vigeland, Haley M. Wahl, Qiaohong Wang, Caitlin A. Witt, David Wright, Olivia Young, Kathryn M. Zurek, and The NANOGrav Collaboration

Subjects
Astrophysics, QB460-466
Published
2024
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2. The NANOGrav 15 yr Data Set: Search for Transverse Polarization Modes in the Gravitational-wave Background

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Jeremy Baier, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Dallas DeGan, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Priyamvada Natarajan, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Alexander Saffer, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Jerry P. Sun, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob A. Taylor, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, Olivia Young, and The NANOGrav Collaboration

Subjects
Gravitational waves, Pulsars, Scalar-tensor-vector gravity, Astrophysics, QB460-466
Abstract

Recently we found compelling evidence for a gravitational-wave background with Hellings and Downs (HD) correlations in our 15 yr data set. These correlations describe gravitational waves as predicted by general relativity, which has two transverse polarization modes. However, more general metric theories of gravity can have additional polarization modes, which produce different interpulsar correlations. In this work, we search the NANOGrav 15 yr data set for evidence of a gravitational-wave background with quadrupolar HD and scalar-transverse (ST) correlations. We find that HD correlations are the best fit to the data and no significant evidence in favor of ST correlations. While Bayes factors show strong evidence for a correlated signal, the data does not strongly prefer either correlation signature, with Bayes factors ∼2 when comparing HD to ST correlations, and ∼1 for HD plus ST correlations to HD correlations alone. However, when modeled alongside HD correlations, the amplitude and spectral index posteriors for ST correlations are uninformative, with the HD process accounting for the vast majority of the total signal. Using the optimal statistic, a frequentist technique that focuses on the pulsar-pair cross-correlations, we find median signal-to-noise ratios of 5.0 for HD and 4.6 for ST correlations when fit for separately, and median signal-to-noise ratios of 3.5 for HD and 3.0 for ST correlations when fit for simultaneously. While the signal-to-noise ratios for each of the correlations are comparable, the estimated amplitude and spectral index for HD are a significantly better fit to the total signal, in agreement with our Bayesian analysis.

Published
2024
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3. The NANOGrav 15 yr Data Set: Chromatic Gaussian Process Noise Models for Six Pulsars

Author

Bjorn Larsen, Chiara M. F. Mingarelli, Jeffrey S. Hazboun, Aurélien Chalumeau, Deborah C. Good, Joseph Simon, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Paul R. Brook, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Ross J. Jennings, Megan L. Jones, David L. Kaplan, Matthew Kerr, Michael T. Lam, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Alexander McEwen, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Cherry Ng, David J. Nice, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Ann Schmiedekamp, Carl Schmiedekamp, Brent J. Shapiro-Albert, Ingrid H. Stairs, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Haley M. Wahl, David J. Champion, Ismaël Cognard, Lucas Guillemot, Huanchen Hu, Michael J. Keith, Kuo Liu, James W. McKee, Aditya Parthasarathy, Delphine Perrodin, Andrea Possenti, Golam M. Shaifullah, and Gilles Theureau

Subjects
Millisecond pulsars, Gravitational wave astronomy, Gravitational wave detectors, Pulsar timing method, Interstellar medium, Astronomy data analysis, Astrophysics, QB460-466
Abstract

Pulsar timing arrays (PTAs) are designed to detect low-frequency gravitational waves (GWs). GWs induce achromatic signals in PTA data, meaning that the timing delays do not depend on radio frequency. However, pulse arrival times are also affected by radio-frequency-dependent “chromatic” noise from sources such as dispersion measure (DM) and scattering delay variations. Furthermore, the characterization of GW signals may be influenced by the choice of chromatic noise model for each pulsar. To better understand this effect, we assess if and how different chromatic noise models affect the achromatic noise properties in each pulsar. The models we compare include existing DM models used by the North American Nanohertz Observatory for Gravitational waves (NANOGrav) and noise models used for the European PTA Data Release 2 (EPTA DR2). We perform this comparison using a subsample of six pulsars from the NANOGrav 15 yr data set, selecting the same six pulsars as from the EPTA DR2 six-pulsar data set. We find that the choice of chromatic noise model noticeably affects the achromatic noise properties of several pulsars. This is most dramatic for PSR J1713+0747, where the amplitude of its achromatic red noise lowers from ${\mathrm{log}}_{10}{A}_{\mathrm{RN}}=-{14.1}_{-0.1}^{+0.1}$ to $-{14.7}_{-0.5}^{+0.3}$ , and the spectral index broadens from ${\gamma }_{\mathrm{RN}}={2.6}_{-0.4}^{+0.5}$ to ${\gamma }_{\mathrm{RN}}={3.5}_{-0.9}^{+1.2}$ . We also compare each pulsar's noise properties with those inferred from the EPTA DR2, using the same models. From the discrepancies, we identify potential areas where the noise models could be improved. These results highlight the potential for custom chromatic noise models to improve PTA sensitivity to GWs.

Published
2024
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4. PINT: Maximum-likelihood Estimation of Pulsar Timing Noise Parameters

Author

Abhimanyu Susobhanan, David L. Kaplan, Anne M. Archibald, Jing Luo, Paul S. Ray, Timothy T. Pennucci, Scott M. Ransom, Gabriella Agazie, William Fiore, Bjorn Larsen, Patrick O’Neill, Rutger van Haasteren, Akash Anumarlapudi, Matteo Bachetti, Deven Bhakta, Chloe A. Champagne, H. Thankful Cromartie, Paul B. Demorest, Ross J. Jennings, Matthew Kerr, Sasha Levina, Alexander McEwen, Brent J. Shapiro-Albert, and Joseph K. Swiggum

Subjects
Pulsars, Astronomy software, Astronomy data analysis, Astrophysics, QB460-466
Abstract

PINT is a pure-Python framework for high-precision pulsar timing developed on top of widely used and well-tested Python libraries, supporting both interactive and programmatic data analysis workflows. We present a new frequentist framework within PINT to characterize the single-pulsar noise processes present in pulsar timing data sets. This framework enables parameter estimation for both uncorrelated and correlated noise processes, as well as model comparison between different timing and noise models in a computationally inexpensive way. We demonstrate the efficacy of the new framework by applying it to simulated data sets as well as a real data set of PSR B1855+09. We also describe the new features implemented in PINT since it was first described in the literature.

Published
2024
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5. The NANOGrav 15 yr Data Set: Search for Anisotropy in the Gravitational-wave Background

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Emiko Gardiner, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, and Olivia Young

Subjects
Gravitational waves, Gravitational wave astronomy, Supermassive black holes, Pulsars, Astrophysics, QB460-466
Abstract

The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has reported evidence for the presence of an isotropic nanohertz gravitational-wave background (GWB) in its 15 yr data set. However, if the GWB is produced by a population of inspiraling supermassive black hole binary (SMBHB) systems, then the background is predicted to be anisotropic, depending on the distribution of these systems in the local Universe and the statistical properties of the SMBHB population. In this work, we search for anisotropy in the GWB using multiple methods and bases to describe the distribution of the GWB power on the sky. We do not find significant evidence of anisotropy. By modeling the angular power distribution as a sum over spherical harmonics (where the coefficients are not bound to always generate positive power everywhere), we find that the Bayesian 95% upper limit on the level of dipole anisotropy is ( C _l _=1 / C _l _=0 ) < 27%. This is similar to the upper limit derived under the constraint of positive power everywhere, indicating that the dipole may be close to the data-informed regime. By contrast, the constraints on anisotropy at higher spherical-harmonic multipoles are strongly prior dominated. We also derive conservative estimates on the anisotropy expected from a random distribution of SMBHB systems using astrophysical simulations conditioned on the isotropic GWB inferred in the 15 yr data set and show that this data set has sufficient sensitivity to probe a large fraction of the predicted level of anisotropy. We end by highlighting the opportunities and challenges in searching for anisotropy in pulsar timing array data.

Published
2023
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6. The NANOGrav 15 yr Data Set: Constraints on Supermassive Black Hole Binaries from the Gravitational-wave Background

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Paul T. Baker, Bence Bécsy, Laura Blecha, Alexander Bonilla, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Belinda D. Cheeseboro, Siyuan Chen, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Curt J. Cutler, Daniel J. D’Orazio, Megan E. DeCesar, Dallas DeGan, Paul B. Demorest, Heling Deng, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Emiko Gardiner, Nate Garver-Daniels, Peter A. Gentile, Kyle A. Gersbach, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Kristina Islo, Ross J. Jennings, Aaron Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tyson B. Littenberg, Tingting Liu, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Priyamvada Natarajan, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Polina Petrov, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Jessie C. Runnoe, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Jerry P. Sun, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob Taylor, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Jeremy M. Wachter, Haley M. Wahl, Qiaohong Wang, Caitlin A. Witt, David Wright, Olivia Young, and The NANOGrav Collaboration

Subjects
Gravitational waves, Supermassive black holes, Galaxy evolution, Astrophysics, QB460-466
Abstract

The NANOGrav 15 yr data set shows evidence for the presence of a low-frequency gravitational-wave background (GWB). While many physical processes can source such low-frequency gravitational waves, here we analyze the signal as coming from a population of supermassive black hole (SMBH) binaries distributed throughout the Universe. We show that astrophysically motivated models of SMBH binary populations are able to reproduce both the amplitude and shape of the observed low-frequency gravitational-wave spectrum. While multiple model variations are able to reproduce the GWB spectrum at our current measurement precision, our results highlight the importance of accurately modeling binary evolution for producing realistic GWB spectra. Additionally, while reasonable parameters are able to reproduce the 15 yr observations, the implied GWB amplitude necessitates either a large number of parameters to be at the edges of expected values or a small number of parameters to be notably different from standard expectations. While we are not yet able to definitively establish the origin of the inferred GWB signal, the consistency of the signal with astrophysical expectations offers a tantalizing prospect for confirming that SMBH binaries are able to form, reach subparsec separations, and eventually coalesce. As the significance grows over time, higher-order features of the GWB spectrum will definitively determine the nature of the GWB and allow for novel constraints on SMBH populations.

Published
2023
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7. The NANOGrav 15 yr Data Set: Bayesian Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Robin Case, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Matthew C. Digman, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Polina Petrov, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob Taylor, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Rutger van Haasteren, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, Olivia Young, and The NANOGrav Collaboration

Subjects
Gravitational wave astronomy, Astrophysics, QB460-466
Abstract

Evidence for a low-frequency stochastic gravitational-wave background has recently been reported based on analyses of pulsar timing array data. The most likely source of such a background is a population of supermassive black hole binaries, the loudest of which may be individually detected in these data sets. Here we present the search for individual supermassive black hole binaries in the NANOGrav 15 yr data set. We introduce several new techniques, which enhance the efficiency and modeling accuracy of the analysis. The search uncovered weak evidence for two candidate signals, one with a gravitational-wave frequency of ∼4 nHz, and another at ∼170 nHz. The significance of the low-frequency candidate was greatly diminished when Hellings–Downs correlations were included in the background model. The high-frequency candidate was discounted due to the lack of a plausible host galaxy, the unlikely astrophysical prior odds of finding such a source, and since most of its support comes from a single pulsar with a commensurate binary period. Finding no compelling evidence for signals from individual binary systems, we place upper limits on the strain amplitude of gravitational waves emitted by such systems. At our most sensitive frequency of 6 nHz, we place a sky-averaged 95% upper limit of 8 × 10 ^−15 on the strain amplitude. We also calculate an exclusion volume and a corresponding effective radius, within which we can rule out the presence of black hole binaries emitting at a given frequency.

Published
2023
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8. The NANOGrav 15 yr Data Set: Evidence for a Gravitational-wave Background

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Belinda D. Cheeseboro, Siyuan Chen, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Curt J. Cutler, Megan E. DeCesar, Dallas DeGan, Paul B. Demorest, Heling Deng, Timothy Dolch, Brendan Drachler, Justin A. Ellis, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Kyle A. Gersbach, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Kristina Islo, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Tonia C. Klein, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tyson B. Littenberg, Tingting Liu, Andrea Lommen, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Margaret A. Mattson, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Priyamvada Natarajan, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Polina Petrov, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Jerry P. Sun, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob Taylor, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Rutger van Haasteren, Sarah J. Vigeland, Haley M. Wahl, Qiaohong Wang, Caitlin A. Witt, Olivia Young, and The NANOGrav Collaboration

Subjects
Gravitational waves, Gravitational wave astronomy, Millisecond pulsars, Radio pulsars, Supermassive black holes, Astrophysics, QB460-466
Abstract

We report multiple lines of evidence for a stochastic signal that is correlated among 67 pulsars from the 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves. The correlations follow the Hellings–Downs pattern expected for a stochastic gravitational-wave background. The presence of such a gravitational-wave background with a power-law spectrum is favored over a model with only independent pulsar noises with a Bayes factor in excess of 10 ^14 , and this same model is favored over an uncorrelated common power-law spectrum model with Bayes factors of 200–1000, depending on spectral modeling choices. We have built a statistical background distribution for the latter Bayes factors using a method that removes interpulsar correlations from our data set, finding p = 10 ^−3 (≈3 σ ) for the observed Bayes factors in the null no-correlation scenario. A frequentist test statistic built directly as a weighted sum of interpulsar correlations yields p = 5 × 10 ^−5 to 1.9 × 10 ^−4 (≈3.5 σ –4 σ ). Assuming a fiducial f ^−2/3 characteristic strain spectrum, as appropriate for an ensemble of binary supermassive black hole inspirals, the strain amplitude is ${2.4}_{-0.6}^{+0.7}\times {10}^{-15}$ (median + 90% credible interval) at a reference frequency of 1 yr ^−1 . The inferred gravitational-wave background amplitude and spectrum are consistent with astrophysical expectations for a signal from a population of supermassive black hole binaries, although more exotic cosmological and astrophysical sources cannot be excluded. The observation of Hellings–Downs correlations points to the gravitational-wave origin of this signal.

Published
2023
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9. The NANOGrav 15 yr Data Set: Observations and Timing of 68 Millisecond Pulsars

Author

Gabriella Agazie, Md Faisal Alam, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Laura Blecha, Victoria Bonidie, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Bence Bécsy, Christopher Chapman, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Cody Jessup, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Anastasia Kuske, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Ye Lin, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Kaleb Maraccini, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Elisa Panciu, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Laura Salo, Shashwat C. Sardesai, Carl Schmiedekamp, Ann Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Qiaohong Wang, Caitlin A. Witt, Olivia Young, and The NANOGrav Collaboration

Subjects
Millisecond pulsars, Pulsar timing method, Time series analysis, Pulsars, Gravitational waves, Astrophysics, QB460-466
Abstract

We present observations and timing analyses of 68 millisecond pulsars (MSPs) comprising the 15 yr data set of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). NANOGrav is a pulsar timing array (PTA) experiment that is sensitive to low-frequency gravitational waves (GWs). This is NANOGrav’s fifth public data release, including both “narrowband” and “wideband” time-of-arrival (TOA) measurements and corresponding pulsar timing models. We have added 21 MSPs and extended our timing baselines by 3 yr, now spanning nearly 16 yr for some of our sources. The data were collected using the Arecibo Observatory, the Green Bank Telescope, and the Very Large Array between frequencies of 327 MHz and 3 GHz, with most sources observed approximately monthly. A number of notable methodological and procedural changes were made compared to our previous data sets. These improve the overall quality of the TOA data set and are part of the transition to new pulsar timing and PTA analysis software packages. For the first time, our data products are accompanied by a full suite of software to reproduce data reduction, analysis, and results. Our timing models include a variety of newly detected astrometric and binary pulsar parameters, including several significant improvements to pulsar mass constraints. We find that the time series of 23 pulsars contain detectable levels of red noise, 10 of which are new measurements. In this data set, we find evidence for a stochastic GW background.

Published
2023
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10. The NANOGrav 15 yr Data Set: Detector Characterization and Noise Budget

Author

Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Maria Charisi, Shami Chatterjee, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Brendan Drachler, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Lydia Guertin, Kayhan Gültekin, Jeffrey S. Hazboun, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, Olivia Young, and The NANOGrav Collaboration

Subjects
Millisecond pulsars, Pulsar timing method, Gravitational wave astronomy, Gravitational wave detectors, Radio astronomy, Astrophysics, QB460-466
Abstract

Pulsar timing arrays (PTAs) are galactic-scale gravitational wave (GW) detectors. Each individual arm, composed of a millisecond pulsar, a radio telescope, and a kiloparsecs-long path, differs in its properties but, in aggregate, can be used to extract low-frequency GW signals. We present a noise and sensitivity analysis to accompany the NANOGrav 15 yr data release and associated papers, along with an in-depth introduction to PTA noise models. As a first step in our analysis, we characterize each individual pulsar data set with three types of white-noise parameters and two red-noise parameters. These parameters, along with the timing model and, particularly, a piecewise-constant model for the time-variable dispersion measure, determine the sensitivity curve over the low-frequency GW band we are searching. We tabulate information for all of the pulsars in this data release and present some representative sensitivity curves. We then combine the individual pulsar sensitivities using a signal-to-noise ratio statistic to calculate the global sensitivity of the PTA to a stochastic background of GWs, obtaining a minimum noise characteristic strain of 7 × 10 ^−15 at 5 nHz. A power-law-integrated analysis shows rough agreement with the amplitudes recovered in NANOGrav’s 15 yr GW background analysis. While our phenomenological noise model does not model all known physical effects explicitly, it provides an accurate characterization of the noise in the data while preserving sensitivity to multiple classes of GW signals.

Published
2023
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11. The NANOGrav 15 yr Data Set: Search for Signals from New Physics

Author

Adeela Afzal, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Jose Juan Blanco-Pillado, Laura Blecha, Kimberly K. Boddy, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Belinda D. Cheeseboro, Siyuan Chen, Tyler Cohen, James M. Cordes, Neil J. Cornish, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Curt J. Cutler, Megan E. DeCesar, Dallas DeGan, Paul B. Demorest, Heling Deng, Timothy Dolch, Brendan Drachler, Richard von Eckardstein, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Kyle A. Gersbach, Joseph Glaser, Deborah C. Good, Lydia Guertin, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Kristina Islo, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Luke Zoltan Kelley, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Vincent S. H. Lee, Natalia Lewandowska, Rafael R. Lino dos Santos, Tyson B. Littenberg, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Patrick M. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Jonathan Nay, Priyamvada Natarajan, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Polina Petrov, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Tobias Schröder, Levi Schult, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Peter Stratmann, Jerry P. Sun, Abhimanyu Susobhanan, Joseph K. Swiggum, Jacob Taylor, Stephen R. Taylor, Tanner Trickle, Jacob E. Turner, Caner Unal, Michele Vallisneri, Sonali Verma, Sarah J. Vigeland, Haley M. Wahl, Qiaohong Wang, Caitlin A. Witt, David Wright, Olivia Young, Kathryn M. Zurek, and The NANOGrav Collaboration

Subjects
Gravitational waves, Cosmology, Particle astrophysics, Gravitational wave sources, Astrophysics, QB460-466
Abstract

The 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) shows positive evidence for the presence of a low-frequency gravitational-wave (GW) background. In this paper, we investigate potential cosmological interpretations of this signal, specifically cosmic inflation, scalar-induced GWs, first-order phase transitions, cosmic strings, and domain walls. We find that, with the exception of stable cosmic strings of field theory origin, all these models can reproduce the observed signal. When compared to the standard interpretation in terms of inspiraling supermassive black hole binaries (SMBHBs), many cosmological models seem to provide a better fit resulting in Bayes factors in the range from 10 to 100. However, these results strongly depend on modeling assumptions about the cosmic SMBHB population and, at this stage, should not be regarded as evidence for new physics. Furthermore, we identify excluded parameter regions where the predicted GW signal from cosmological sources significantly exceeds the NANOGrav signal. These parameter constraints are independent of the origin of the NANOGrav signal and illustrate how pulsar timing data provide a new way to constrain the parameter space of these models. Finally, we search for deterministic signals produced by models of ultralight dark matter (ULDM) and dark matter substructures in the Milky Way. We find no evidence for either of these signals and thus report updated constraints on these models. In the case of ULDM, these constraints outperform torsion balance and atomic clock constraints for ULDM coupled to electrons, muons, or gluons.

Published
2023
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12. How to Detect an Astrophysical Nanohertz Gravitational Wave Background

Author

Bence Bécsy, Neil J. Cornish, Patrick M. Meyers, Luke Zoltan Kelley, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Laura Blecha, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, J. Andrew Casey-Clyde, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Tyler Cohen, James M. Cordes, Fronefield Crawford, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Deborah C. Good, Kayhan Gültekin, Jeffrey S. Hazboun, Sophie Hourihane, Ross J. Jennings, Aaron D. Johnson, Megan L. Jones, Andrew R. Kaiser, David L. Kaplan, Matthew Kerr, Joey S. Key, Nima Laal, Michael T. Lam, William G. Lamb, T. Joseph W. Lazio, Natalia Lewandowska, Tyson B. Littenberg, Tingting Liu, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Chung-Pei Ma, Dustin R. Madison, Alexander McEwen, James W. McKee, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Chiara M. F. Mingarelli, Andrea Mitridate, Cherry Ng, David J. Nice, Stella Koch Ocker, Ken D. Olum, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Joseph D. Romano, Shashwat C. Sardesai, Ann Schmiedekamp, Carl Schmiedekamp, Kai Schmitz, Brent J. Shapiro-Albert, Xavier Siemens, Joseph Simon, Magdalena S. Siwek, Sophia V. Sosa Fiscella, Ingrid H. Stairs, Daniel R. Stinebring, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Stephen R. Taylor, Jacob E. Turner, Caner Unal, Michele Vallisneri, Rutger van Haasteren, Sarah J. Vigeland, Haley M. Wahl, Caitlin A. Witt, and Olivia Young

Subjects
Gravitational waves, Gravitational wave sources, Gravitational wave astronomy, Supermassive black holes, Astronomy data analysis, Bayesian statistics, Astrophysics, QB460-466
Abstract

Analyses of pulsar timing data have provided evidence for a stochastic gravitational wave background in the nanohertz frequency band. The most plausible source of this background is the superposition of signals from millions of supermassive black hole binaries. The standard statistical techniques used to search for this background and assess its significance make several simplifying assumptions, namely (i) Gaussianity, (ii) isotropy, and most often, (iii) a power-law spectrum. However, a stochastic background from a finite collection of binaries does not exactly satisfy any of these assumptions. To understand the effect of these assumptions, we test standard analysis techniques on a large collection of realistic simulated data sets. The data-set length, observing schedule, and noise levels were chosen to emulate the NANOGrav 15 yr data set. Simulated signals from millions of binaries drawn from models based on the Illustris cosmological hydrodynamical simulation were added to the data. We find that the standard statistical methods perform remarkably well on these simulated data sets, even though their fundamental assumptions are not strictly met. They are able to achieve a confident detection of the background. However, even for a fixed set of astrophysical parameters, different realizations of the universe result in a large variance in the significance and recovered parameters of the background. We also find that the presence of loud individual binaries can bias the spectral recovery of the background if we do not account for them.

Published
2023
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13. Scattering Delay Mitigation in High-accuracy Pulsar Timing: Cyclic Spectroscopy Techniques

Author

Jacob E. Turner, Daniel R. Stinebring, Maura A. McLaughlin, Anne M. Archibald, Timothy Dolch, and Ryan S. Lynch

Subjects
Interstellar medium, Pulsar timing method, Radio pulsars, Interstellar scattering, Astrophysics, QB460-466
Abstract

We simulate scattering delays from the interstellar medium to examine the effectiveness of three estimators in recovering these delays in pulsar timing data. Two of these estimators use the more traditional process of fitting autocorrelation functions to pulsar dynamic spectra to extract scintillation bandwidths, while the third estimator uses the newer technique of cyclic spectroscopy on baseband pulsar data to recover the interstellar medium’s impulse response function. We find that either fitting a Lorentzian or Gaussian distribution to an autocorrelation function or recovering the impulse response function from the cyclic spectrum are, on average, accurate in recovering scattering delays, although autocorrelation function estimators have a large variance, even at high signal-to-noise ratio (S/N). We find that, given sufficient S/N, cyclic spectroscopy is more accurate than both Gaussian and Lorentzian fitting for recovering scattering delays at specific epochs, suggesting that cyclic spectroscopy is a superior method for scattering estimation in high-quality data.

Published
2023
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14. The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package*

Author

Adrian M. Price-Whelan, Pey Lian Lim, Nicholas Earl, Nathaniel Starkman, Larry Bradley, David L. Shupe, Aarya A. Patil, Lia Corrales, C. E. Brasseur, Maximilian Nöthe, Axel Donath, Erik Tollerud, Brett M. Morris, Adam Ginsburg, Eero Vaher, Benjamin A. Weaver, James Tocknell, William Jamieson, Marten H. van Kerkwijk, Thomas P. Robitaille, Bruce Merry, Matteo Bachetti, H. Moritz Günther, Thomas L. Aldcroft, Jaime A. Alvarado-Montes, Anne M. Archibald, Attila Bódi, Shreyas Bapat, Geert Barentsen, Juanjo Bazán, Manish Biswas, Médéric Boquien, D. J. Burke, Daria Cara, Mihai Cara, Kyle E Conroy, Simon Conseil, Matthew W. Craig, Robert M. Cross, Kelle L. Cruz, Francesco D’Eugenio, Nadia Dencheva, Hadrien A. R. Devillepoix, Jörg P. Dietrich, Arthur Davis Eigenbrot, Thomas Erben, Leonardo Ferreira, Daniel Foreman-Mackey, Ryan Fox, Nabil Freij, Suyog Garg, Robel Geda, Lauren Glattly, Yash Gondhalekar, Karl D. Gordon, David Grant, Perry Greenfield, Austen M. Groener, Steve Guest, Sebastian Gurovich, Rasmus Handberg, Akeem Hart, Zac Hatfield-Dodds, Derek Homeier, Griffin Hosseinzadeh, Tim Jenness, Craig K. Jones, Prajwel Joseph, J. Bryce Kalmbach, Emir Karamehmetoglu, Mikołaj Kałuszyński, Michael S. P. Kelley, Nicholas Kern, Wolfgang E. Kerzendorf, Eric W. Koch, Shankar Kulumani, Antony Lee, Chun Ly, Zhiyuan Ma, Conor MacBride, Jakob M. Maljaars, Demitri Muna, N. A. Murphy, Henrik Norman, Richard O’Steen, Kyle A. Oman, Camilla Pacifici, Sergio Pascual, J. Pascual-Granado, Rohit R. Patil, Gabriel I Perren, Timothy E. Pickering, Tanuj Rastogi, Benjamin R. Roulston, Daniel F Ryan, Eli S. Rykoff, Jose Sabater, Parikshit Sakurikar, Jesús Salgado, Aniket Sanghi, Nicholas Saunders, Volodymyr Savchenko, Ludwig Schwardt, Michael Seifert-Eckert, Albert Y. Shih, Anany Shrey Jain, Gyanendra Shukla, Jonathan Sick, Chris Simpson, Sudheesh Singanamalla, Leo P. Singer, Jaladh Singhal, Manodeep Sinha, Brigitta M. Sipőcz, Lee R. Spitler, David Stansby, Ole Streicher, Jani Šumak, John D. Swinbank, Dan S. Taranu, Nikita Tewary, Grant R. Tremblay, Miguel de Val-Borro, Samuel J. Van Kooten, Zlatan Vasović, Shresth Verma, José Vinícius de Miranda Cardoso, Peter K. G. Williams, Tom J. Wilson, Benjamin Winkel, W. M. Wood-Vasey, Rui Xue, Peter Yoachim, Chen Zhang, and Andrea Zonca

Published
2022
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15. SciPy 1.0-Fundamental Algorithms for Scientific Computing in Python.

Author

Pauli Virtanen, Ralf Gommers, Travis E. Oliphant, Matt Haberland, Tyler Reddy, David Cournapeau, Evgeni Burovski, Pearu Peterson, Warren Weckesser, Jonathan Bright, Stéfan van der Walt, Matthew Brett, Joshua Wilson, K. Jarrod Millman, Nikolay Mayorov, Andrew R. J. Nelson, Eric Jones, Robert Kern, Eric Larson, CJ Carey, Ilhan Polat, Yu Feng, Eric W. Moore, Jake VanderPlas, Denis Laxalde, Josef Perktold, Robert Cimrman, Ian Henriksen, E. A. Quintero, Charles R. Harris, Anne M. Archibald, Antônio H. Ribeiro, Fabian Pedregosa, Paul van Mulbregt, and SciPy 1. 0 Contributors

Published
2019

17. Highly polarized microstructure from the repeating FRB 20180916B

Author

A. Keimpema, K. Nimmo, F. Kirsten, Z. Paragi, Benito Marcote, Anne M. Archibald, Ramesh Karuppusamy, Jason W. T. Hessels, D. Z. Li, James M. Cordes, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Linear polarization, Scattering, Fast radio burst, Astrophysics::High Energy Astrophysical Phenomena, Astronomy and Astrophysics, Astrophysics, Polarization (waves), Position angle, 01 natural sciences, Orders of magnitude (time), 0103 physical sciences, Very-long-baseline interferometry, 010303 astronomy & astrophysics, Circular polarization, 0105 earth and related environmental sciences
Abstract

Fast radio bursts (FRBs) are bright, coherent, short-duration radio transients of as-yet unknown extragalactic origin. FRBs exhibit a variety of spectral, temporal and polarimetric properties that can unveil clues into their emission physics and propagation effects in the local medium. Here, we present the high-time-resolution (down to 1 μs) polarimetric properties of four 1.7 GHz bursts from the repeating FRB 20180916B, which were detected in voltage data during observations with the European Very Long Baseline Interferometry Network. We observe a range of emission timescales that spans three orders of magnitude, with the shortest component width reaching 3–4 μs (below which we are limited by scattering). We demonstrate that all four bursts are highly linearly polarized (≳80%), show no evidence of significant circular polarization (≲15%), and exhibit a constant polarization position angle (PPA) during and between bursts. On short timescales (≲100 μs), however, there appear to be subtle PPA variations (of a few degrees) across the burst profiles. These observational results are most naturally explained in an FRB model in which the emission is magnetospheric in origin, in contrast to models in which the emission originates at larger distances in a relativistic shock. High-time-resolution observations of the repeating fast radio burst source FRB 20180916B reveal changes to the polarization properties of the emission on timescales of a few microseconds, indicating an origin in the source magnetosphere.

Published
2021

18. Quasi-simultaneous Radio/X-Ray Observations of the Candidate Transitional Millisecond Pulsar 3FGL J1544.6-1125 during its Low-luminosity Accretion-disk State

Author

Amruta D. Jaodand, Adam T. Deller, Nina Gusinskaia, Jason W. T. Hessels, James C. A. Miller-Jones, Anne M. Archibald, Slavko Bogdanov, Cees Bassa, Rudy Wijnands, Alessandro Patruno, Sotiris Sanidas, European Commission, Australian Research Council, National Aeronautics and Space Administration (US), Columbia University, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Millisecond pulsars, Radio continuum emission, Accretion, Space and Planetary Science, Binary pulsars, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

3FGL J1544.6-1125 is a candidate transitional millisecond pulsar (tMSP). Similar to the well-established tMSPs - PSR J1023+0038, IGR J18245-2452, and XSS J12270-4859 -- 3FGL J1544.6-1125 shows $\gamma$-ray emission and discrete X-ray "low" and "high" modes during its low-luminosity accretion-disk state. Coordinated radio/X-ray observations of PSR J1023+0038 in its current low-luminosity accretion-disk state showed rapidly variable radio continuum emission-possibly originating from a compact, self-absorbed jet, the "propellering" of accretion material, and/or pulsar moding. 3FGL J1544.6-1125 is currently the only other (candidate) tMSP system in this state, and can be studied to see whether tMSPs are typically radio-loud compared to other neutron star binaries. In this work, we present a quasi-simultaneous Very Large Array and Swift radio/X-ray campaign on 3FGL J1544.6-1125. We detect 10 GHz radio emission varying in flux density from $47.7 \pm 6.0$ $\mu$Jy down to $\sim$15 $\mu$Jy (3$\sigma$ upper limit) at four epochs spanning three weeks. At the brightest epoch, the radio luminosity is $L_{5 GHz}$ $= (2.17 \pm 0.17) \times 10^{27}$ erg s$^{-1}$ for a quasi-simultaneous X-ray luminosity $L_{2-10 keV}$ $= (4.32 \pm 0.23) \times 10^{33}$ erg s$^{-1}$ (for an assumed distance of 3.8 kpc). These luminosities are close to those of PSR J1023+0038, and the results strengthen the case that 3FGL J1544.6-1125 is a tMSP showing similar phenomenology to PSR J1023+0038., Comment: Accepted for publication in the Astrophysical Journal

Published
2021

19. Quasi-simultaneous radio and X-ray observations of Aql X-1: Probing low luminosities

Author

Craig O. Heinke, Nathalie Degenaar, Jason W. T. Hessels, John A. Tomsick, J. Moldon, Adam Deller, N. V. Gusinskaia, Rudy Wijnands, Anne M. Archibald, James Miller-Jones, Alessandro Patruno, European Commission, Australian Research Council, Netherlands Organization for Scientific Research, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Binary number, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Luminosity, X-rays: binaries, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Jet (fluid), Accretion (meteorology), 010308 nuclear & particles physics, neutron [Stars], Astronomy and Astrophysics, Stars: neutron, Neutron star, Space and Planetary Science, binaries [X-rays], Outflow, Astrophysics - High Energy Astrophysical Phenomena, Order of magnitude
Abstract

Aql X-1 is one of the best-studied neutron star low-mass X-ray binaries. It was previously targeted using quasi-simultaneous radio and X-ray observations during at least 7 different accretion outbursts. Such observations allow us to probe the interplay between accretion inflow (X-ray) and jet outflow (radio). Thus far, these combined observations have only covered one order of magnitude in radio and X-ray luminosity range; this means that any potential radio - X-ray luminosity correlation, $L_R \propto L_X^{\beta}$, is not well constrained ($\beta \approx$ 0.4-0.9, based on various studies) or understood. Here we present quasi-simultaneous Very Large Array and Swift-XRT observations of Aql X-1's 2016 outburst, with which we probe one order of magnitude fainter in radio and X-ray luminosity compared to previous studies ($6 \times 10^{34} < L_X < 3 \times 10^{35}$ erg s$^{-1}$, i.e., the intermediate to low-luminosity regime between outburst peak and quiescence). The resulting radio non-detections indicate that Aql X-1's radio emission decays more rapidly at low X-ray luminosities than previously assumed - at least during the 2016 outburst. Assuming similar behaviour between outbursts, and combining all available data, this can be modelled as a steep $\beta=1.17^{+0.30}_{-0.21}$ power-law index or as a sharp radio cut-off at $L_X \lesssim 5 \times 10^{35}$ erg s$^{-1}$ (given our deep radio upper limits at X-ray luminosities below this value). We discuss these results in the context of other similar studies., Comment: 15 pages, 11 figures, 3 tables, accepted for publication in MNRAS

Published
2020

20. The GBT 350-MHz Drift Scan Pulsar Survey: III. Detection of a magnetic field in the eclipsing material of PSR J2256-1024

Author

Kathryn Crowter, Christie A. McPhee, Duncan R. Lorimer, J. Boyles, Mallory S. E. Roberts, Scott M. Ransom, Jason W. T. Hessels, Kevin Stovall, Ryan S. Lynch, Maura McLaughlin, Anne M. Archibald, Ingrid H. Stairs, Joeri van Leeuwen, C. Karako-Argaman, High Energy Astrophys. & Astropart. Phys (API, FNWI), and Faculty of Science

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Linear polarization, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Polarization (waves), 01 natural sciences, Magnetic field, Wavelength, symbols.namesake, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Faraday effect, symbols, Potential source, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
Abstract

We present the first measurement of a non-zero magnetic field in the eclipsing material of a black widow pulsar. Black widows are millisecond pulsars which are ablating their companions; therefore they are often proposed as one potential source of isolated millisecond pulsars. PSR J2256-1024 is an eclipsing black widow discovered at radio wavelengths and later also observed in the X-ray and gamma parts of the spectrum. Here we present the radio timing solution for PSR J2256-1024, polarization profiles at 350, 820, and 1500~MHz and an investigation of changes in the polarization profile due to eclipsing material in the system. In the latter we find evidence of Faraday rotation in the linear polarization shortly after eclipse, measuring a rotation measure of 0.44(6) rad per meter squared and a corresponding line-of-sight magnetic field of 3.5(17) mG., 14 pages, 8 figures

Published
2020

21. Author Correction: SciPy 1.0: fundamental algorithms for scientific computing in Python

Author

Pauli Virtanen, Robert Kern, Antônio H. Ribeiro, Eric Moore, Andrew Nelson, Yu Feng, Paul van Mulbregt, Josef Perktold, Robert Cimrman, Tyler Reddy, Anne M. Archibald, Ralf Gommers, CJ Carey, K. Jarrod Millman, Jonathan Bright, Charles R. Harris, Warren Weckesser, Travis E. Oliphant, SciPy . Contributors, Eric Jones, Nikolay Mayorov, Pearu Peterson, Jake Vanderplas, Joshua Wilson, Stefan van der Walt, David Cournapeau, Eric Larson, Ian Henriksen, Fabian Pedregosa, Matthew Brett, Evgeni Burovski, Eric Quintero, Matt Haberland, Denis Laxalde, and Ilhan Polat

Subjects
Technology, Computer science, computer.software_genre, Biochemistry, History, 21st Century, Models, Biological, Biophysical chemistry, Computer Simulation, Author Correction, Molecular Biology, computer.programming_language, Programming language, Published Erratum, Computational Biology, Signal Processing, Computer-Assisted, Cell Biology, Python (programming language), History, 20th Century, Computational biology and bioinformatics, Nonlinear Dynamics, Perspective, Linear Models, Programming Languages, computer, Algorithms, Software, Biotechnology
Abstract

SciPy is an open-source scientific computing library for the Python programming language. Since its initial release in 2001, SciPy has become a de facto standard for leveraging scientific algorithms in Python, with over 600 unique code contributors, thousands of dependent packages, over 100,000 dependent repositories and millions of downloads per year. In this work, we provide an overview of the capabilities and development practices of SciPy 1.0 and highlight some recent technical developments., This Perspective describes the development and capabilities of SciPy 1.0, an open source scientific computing library for the Python programming language.

Published
2020

22. Common-spectrum process versus cross-correlation for gravitational-wave searches using pulsar timing arrays

Author

Joseph D. Romano, Anne M. Archibald, Xavier Siemens, and Jeffrey S. Hazboun

Subjects
Physics, Cross-correlation, 010308 nuclear & particles physics, Gravitational wave, Estimator, FOS: Physical sciences, Astrophysics, General Relativity and Quantum Cosmology (gr-qc), Expected value, 01 natural sciences, General Relativity and Quantum Cosmology, Pulsar, Frequentist inference, Observatory, 0103 physical sciences, 010306 general physics, Noise (radio)
Abstract

The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has recently reported strong statistical evidence for a common-spectrum red-noise process for all pulsars, as seen in their 12.5-yr analysis for an isotropic stochastic gravitational-wave background. However, there is currently very little evidence for quadrupolar spatial correlations across the pulsars in the array, which is needed to make a confident claim of detection of a stochastic background. Here we give a frequentist analysis of a very simple signal+noise model showing that the current lack of evidence for spatial correlations is consistent with the magnitude of the correlation coefficients for pairs of Earth-pulsar baselines in the array, and the fact that pulsar timing arraysbare most-likely operating in the intermediate-signal regime. We derive analytic expressions that allow one to compare the expected values of the signal-to-noise ratios for both the common-spectrum and cross-correlation estimators., Comment: 9 pages, 3 figures

Published
2020
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23. PINT: A Modern Software Package for Pulsar Timing

Author

Matthew Kerr, Kevin Stovall, Jing Luo, Fredrick A. Jenet, Jonathan Colen, Chloe A. Champagne, Paul S. Ray, Ross J. Jennings, Camryn Phillips, Paul Demorest, Scott M. Ransom, Rutger van Haasteren, Anne M. Archibald, Josef Zimmerman, Michael T. Lam, Matteo Bachetti, ITA, and USA

Subjects
010308 nuclear & particles physics, business.industry, Computer science, NumPy, Software development, FOS: Physical sciences, Astronomy and Astrophysics, Modular design, Python (programming language), computer.software_genre, 01 natural sciences, Extensibility, Software, Pulsar, Space and Planetary Science, 0103 physical sciences, Test suite, Operating system, business, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, computer, Instrumentation and Methods for Astrophysics (astro-ph.IM), computer.programming_language
Abstract

Over the past few decades, the measurement precision of some pulsar-timing experiments has advanced from ~10 us to ~10 ns, revealing many subtle phenomena. Such high precision demands both careful data handling and sophisticated timing models to avoid systematic error. To achieve these goals, we present PINT (PINT Is Not Tempo3), a high-precision Python pulsar timing data analysis package, which is hosted on GitHub and available on Python Package Index (PyPI) as pint-pulsar. PINT is well-tested, validated, object-oriented, and modular, enabling interactive data analysis and providing an extensible and flexible development platform for timing applications. It utilizes well-debugged public Python packages (e.g., the NumPy and Astropy libraries) and modern software development schemes (e.g., version control and efficient development with git and GitHub) and a continually expanding test suite for improved reliability, accuracy, and reproducibility. PINT is developed and implemented without referring to, copying, or transcribing the code from other traditional pulsar timing software packages (e.g., TEMPO and TEMPO2) and therefore provides a robust tool for cross-checking timing analyses and simulating pulse arrival times. In this paper, we describe the design, usage, and validation of PINT, and we compare timing results between it and TEMPO and TEMPO2., Comment: Re-submitted to the Astrophysical Journal at December 31st, 2020

Published
2020
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24. Testing the Universality of Free Fall with the Triple System J0337+1715

Author

R. S. Lynch, Duncan R. Lorimer, Scott M. Ransom, Anne M. Archibald, N. V. Gusinskaia, Jason W. T. Hessels, Ingrid H. Stairs, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, 010504 meteorology & atmospheric sciences, Triple system, Astrophysics::High Energy Astrophysical Phenomena, White dwarf, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Universality (dynamical systems), Gravitation, Neutron star, Theory of relativity, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

The millisecond pulsar PSR J0337+1715 is in a mildly relativistic hierarchical triple system with two white dwarfs. This offers the possibility of testing the universality of free fall: does the neutron star fall with the same acceleration as the inner white dwarf in the gravity of the outer white dwarf? We have carried out an intensive pulsar timing campaign, yielding some 27000 pulse time-of-arrival (TOA) measurements with a median uncertainty of 1.2 μs. Here we describe our analysis procedure and timing model.

Published
2018

25. FRB 121102 Bursts Show Complex Time-Frequency Structure

Author

Cees Bassa, Liam Connor, Julia Deneva, J. M. Cordes, Jason W. T. Hessels, Andrew Seymour, V. M. Kaspi, Fronefield Crawford, Shami Chatterjee, Maura McLaughlin, Vishal Gajjar, Ben Stappers, D. Michilli, Scott M. Ransom, Geoffrey C. Bower, Emily Petroff, Laura Spitler, K. Gourdji, Casey J. Law, Zsolt Paragi, Shriharsh P. Tendulkar, Benito Marcote, Anne M. Archibald, A. Keimpema, P. Scholz, Ryan S. Lynch, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
010504 meteorology & atmospheric sciences, Non-thermal [radiation mechanisms], Astrophysics::High Energy Astrophysical Phenomena, radio continuum: general, FOS: Physical sciences, Astrophysics, 01 natural sciences, General [radio continuum], Dwarf [Galaxies], 0103 physical sciences, Dispersion (optics), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Envelope (waves), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nebula, Fast radio burst, Astronomy and Astrophysics, galaxies: dwarf, radiation mechanisms: non-thermal, Secular variation, Pulse (physics), Space and Planetary Science, Stochastic drift, Radio frequency, Astrophysics - High Energy Astrophysical Phenomena
Abstract

FRB 121102 is the only known repeating fast radio burst source. Here we analyze a wide-frequency-range (1-8 GHz) sample of high-signal-to-noise, coherently dedispersed bursts detected using the Arecibo and Green Bank telescopes. These bursts reveal complex time-frequency structures that include sub-bursts with finite bandwidths. The frequency-dependent burst structure complicates the determination of a dispersion measure (DM); we argue that it is appropriate to use a DM metric that maximizes frequency-averaged pulse structure, as opposed to peak signal-to-noise, and find DM = 560.57 +/- 0.07 pc/cc at MJD 57644. After correcting for dispersive delay, we find that the sub-bursts have characteristic frequencies that typically drift lower at later times in the total burst envelope. In the 1.1-1.7 GHz band, the ~ 0.5-1-ms sub-bursts have typical bandwidths ranging from 100-400 MHz, and a characteristic drift rate of ~ 200 MHz/ms towards lower frequencies. At higher radio frequencies, the sub-burst bandwidths and drift rate are larger, on average. While these features could be intrinsic to the burst emission mechanism, they could also be imparted by propagation effects in the medium local to the source. Comparison of the burst DMs with previous values in the literature suggests an increase of Delta(DM) ~ 1-3 pc/cc in 4 years, though this could be a stochastic variation as opposed to a secular trend. This implies changes in the local medium or an additional source of frequency-dependent delay. Overall, the results are consistent with previously proposed scenarios in which FRB 121102 is embedded in a dense nebula., Comment: Submitted to ApJ; comments welcome

Published
2019
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26. The Green Bank North Celestial Cap Pulsar Survey

Author

Megan E. DeCesar, M. D. Rohr, Emmanuel Fonseca, R. Roekle, J. G. Martinez, A. N. Walker, Maura McLaughlin, L. Daniels, Bingyi Cui, Renée Spiewak, Scott M. Ransom, J. van Leeuwen, S. Leake, Ryan S. Lynch, Anne M. Archibald, A. Mata, J. Flanigan, V. M. Kaspi, B. L. Wells, Joseph K. Swiggum, H. Al Noori, Kevin Stovall, David L. Kaplan, Ingrid H. Stairs, D. Day, C. Karako-Argaman, A. Cruz, Christopher M. Biwer, N. Meyers, L. P. Dartez, X. Siemens, Jason Boyles, Mallory S. E. Roberts, Jason W. T. Hessels, R. J. Aloisi, J. Hinojosa, A. Schuett, S. Banaszak, V. I. Kondratiev, A. J. Ford, Lina Levin, P. Chawla, G. Lunsford, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Compact star, 01 natural sciences, Pulsar, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Extreme value theory, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Spin-½
Abstract

We present timing solutions for four pulsars discovered in the Green Bank Northern Celestial Cap (GBNCC) survey. All four pulsars are isolated with spin periods between 0.26$\,$s and 1.84$\,$s. PSR J0038$-$2501 has a 0.26$\,$s period and a period derivative of ${7.6} \times {10}^{-19}\,{\rm s\,s}^{-1}$, which is unusually low for isolated pulsars with similar periods. This low period derivative may be simply an extreme value for an isolated pulsar or it could indicate an unusual evolution path for PSR J0038$-$2501, such as a disrupted recycled pulsar (DRP) from a binary system or an orphaned central compact object (CCO). Correcting the observed spin-down rate for the Shklovskii effect suggests that this pulsar may have an unusually low space velocity, which is consistent with expectations for DRPs. There is no X-ray emission detected from PSR J0038$-$2501 in an archival swift observation, which suggests that it is not a young orphaned CCO. The high dispersion measure of PSR J1949+3426 suggests a distance of 12.3$\,$kpc. This distance indicates that PSR J1949+3426 is among the most distant 7% of Galactic field pulsars, and is one of the most luminous pulsars., Comment: 7 pages, 5 figures

Published
2019

27. Universality of free fall from the orbital motion of a pulsar in a stellar triple system

Author

Ryan S. Lynch, David L. Kaplan, N. V. Gusinskaia, Duncan R. Lorimer, Scott M. Ransom, Adam Deller, Ingrid H. Stairs, Anne M. Archibald, Jason W. T. Hessels, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, Multidisciplinary, 010308 nuclear & particles physics, General relativity, Strong gravity, White dwarf, Astrophysics, 01 natural sciences, Alternatives to general relativity, Gravitation, Gravitational field, Pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Gravitational binding energy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Einstein's theory of gravity, general relativity, has passed stringent tests in laboratories, elsewhere in the Solar Sytem, and in pulsar binaries. Nevertheless it is known to be incompatible with quantum mechanics and must differ from the true behaviour of matter in strong fields and at small spatial scales. A key aspect of general relativity to test is the strong equivalence principle (SEP), which states that all freely falling objects, regardless of how strong their gravity, experience the same acceleration in the same gravitational field. Essentially all alternatives to general relativity violate this principle at some level. Previous direct tests of the SEP are limited by the weak gravity of the bodies in the Earth-Moon-Sun system or by the weak gravitational pull of the Galaxy on pulsar-white dwarf binaries. PSR~J0337+1715 is a hierarchical stellar triple system, where the inner binary consists of a millisecond radio pulsar in a $1.6$-day orbit with a white dwarf. This inner binary is in a $327$-day orbit with another white dwarf. In this system, the pulsar and the inner companion fall toward the outer companion with an acceleration about $10^8$ times greater than that produced by falling in the Galactic potential, and the pulsar's gravitational binding energy is roughly $10\%$ of its mass. Here we report that in spite of the pulsar's strong gravity, the accelerations experienced by it and the inner white dwarf differ by a fraction of no more than $2.6\times 10^{-6}$ ($95\%$ confidence level). We can roughly compare this to other SEP tests by using the strong-field Nordtvedt parameter $\hat\eta_N$. Our limit on $\hat\eta_N$ is a factor of ten smaller than that obtained from (weak-field) Solar-System SEP tests and a factor of almost a thousand smaller than that obtained from other strong-field SEP tests.

Published
2018

28. The Green Bank North Celestial Cap Pulsar Survey

Author

Ryan S. Lynch, G. Lunsford, Victoria M. Kaspi, J. Flanigan, Mallory S. E. Roberts, Maura McLaughlin, Fredrick A. Jenet, Kevin Stovall, Hind Al Noori, Renée Spiewak, L. P. Dartez, Jason Boyles, D. Day, Megan E. DeCesar, A. J. Ford, Bingyi Cui, S. Leake, Anne M. Archibald, Arielle N. Walker, Emmanuel Fonseca, S. Bradley Cenko, M. D. Rohr, Scott M. Ransom, V. I. Kondratiev, Ingrid H. Stairs, J. Hinojosa, B. L. Wells, Jason W. T. Hessels, S. Banaszak, A. Mata, Xavier Siemens, Lina Levin, Pradip Gatkine, Joeri van Leeuwen, P. Chawla, J. G. Martinez, Joseph K. Swiggum, David L. Kaplan, C. Karako-Argaman, Christopher M. Biwer, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Proper motion, 010308 nuclear & particles physics, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, Green Bank Telescope, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Shapiro delay, general [pulsars], Binary pulsar, Neutron star, Pulsar, proper motions, surveys, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
Abstract

We provide timing solutions for 45 radio pulsars discovered by the Robert C. Byrd Green Bank Telescope. These pulsars were found in the Green Bank North Celestial Cap pulsar survey, an all-GBT-sky survey being carried out at a frequency of 350 MHz. We include pulsar timing data from the Green Bank Telescope and Low Frequency Array. Our sample includes five fully recycled millisecond pulsars (MSPs, three of which are in a binary system), a new relativistic double neutron star system, an intermediate mass binary pulsar, a mode-changing pulsar, a 138-ms pulsar with a very low magnetic field, and several nulling pulsars. We have measured two post-Keplerian parameters and thus the masses of both objects in the double neutron star system. We also report a tentative companion mass measurement via Shapiro delay in a binary MSP. Two of the MSPs can be timed with high precision and have been included in pulsar timing arrays being used to search for low-frequency gravitational waves, while a third MSP is a member of the black widow class of binaries. Proper motion is measurable in five pulsars and we provide an estimate of their space velocity. We report on an optical counterpart to a new black widow system and provide constraints on the optical counterparts to other binary MSPs. We also present a preliminary analysis of nulling pulsars in our sample. These results demonstrate the scientific return of long timing campaigns on pulsars of all types., Accepted for publication in The Astrophysical Journal; 30 pages, 9 figures, 8 tables

Published
2018
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29. An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102

Author

George Heald, F. Fernandez, Laura Spitler, Elizabeth A. K. Adams, Daniele Michilli, Robert Wharton, Casey Brinkman, P. J. Van Rooy, Geoffrey C. Bower, Vishal Gajjar, Gregory Hellbourg, Charlotte Sobey, Benito Marcote, T. J. W. Lazio, Casey J. Law, D. Whitlow, A. Seymour, Shriharsh P. Tendulkar, Scott M. Ransom, C. G. Bassa, V. M. Kaspi, Andrew Siemion, Maura McLaughlin, R. S. Lynch, James M. Cordes, Paul Demorest, K. Gourdji, Zsolt Paragi, Jason W. T. Hessels, Anne M. Archibald, Shami Chatterjee, Natasha Maddox, P. Scholz, Slavko Bogdanov, High Energy Astrophys. & Astropart. Phys (API, FNWI), API Other Research (FNWI), and Astronomy

Subjects
POLARIZATION, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, SAGITTARIUS-A-ASTERISK, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Supernova remnant, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nebula, Multidisciplinary, 010308 nuclear & particles physics, Fast radio burst, Canadian Hydrogen Intensity Mapping Experiment, FARADAY-ROTATION, FIELDS, Redshift, Black hole, CRAB-NEBULA, Neutron star, Crab Nebula, GAMMA-RAY, HOST GALAXY, SUPERNOVA REMNANT, BLACK-HOLE, X-RAY, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Fast radio bursts (FRBs) are millisecond-duration, extragalactic radio flashes of unknown physical origin. FRB 121102, the only known repeating FRB source, has been localized to a star-forming region in a dwarf galaxy at redshift z = 0.193, and is spatially coincident with a compact, persistent radio source. The origin of the bursts, the nature of the persistent source, and the properties of the local environment are still debated. Here we present bursts that show ~100% linearly polarized emission at a very high and variable Faraday rotation measure in the source frame: RM_src = +1.46 x 10^5 rad m^-2 and +1.33 x 10^5 rad m^-2 at epochs separated by 7 months, in addition to narrow (< 30 mus) temporal structure. The large and variable rotation measure demonstrates that FRB 121102 is in an extreme and dynamic magneto-ionic environment, while the short burst durations argue for a neutron star origin. Such large rotation measures have, until now, only been observed in the vicinities of massive black holes (M_BH > 10^4 MSun). Indeed, the properties of the persistent radio source are compatible with those of a low-luminosity, accreting massive black hole. The bursts may thus come from a neutron star in such an environment. However, the observed properties may also be explainable in other models, such as a highly magnetized wind nebula or supernova remnant surrounding a young neutron star., Published in Nature: DOI: 10.1038/nature25149

Published
2018

30. Highest Frequency Detection of FRB 121102 at 4-8 GHz Using the Breakthrough Listen Digital Backend at the Green Bank Telescope

Author

David MacMahon, Andrew Siemion, Dan Werthimer, Geoffrey C. Bower, Maura McLaughlin, Casey Brinkman, Danny C. Price, Scott M. Ransom, Yunfan Gerry Zhang, Laura Spitler, Jason W. T. Hessels, D. Michilli, Nectaria A. B. Gizani, Anne M. Archibald, V. M. Kaspi, Ryan S. Lynch, T. J. W. Lazio, Griffin Foster, Matt Lebofsky, P. Scholz, Howard Isaacson, Gregory Hellbourg, Casey J. Law, J. Emilio Enriquez, Steve Croft, Shriharsh P. Tendulkar, Suvro Chatterjee, Vishal Gajjar, Andrew Seymour, Sarah Burke-Spolaor, J. M. Cordes, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Scintillation, 010308 nuclear & particles physics, Fast radio burst, Linear polarization, Canadian Hydrogen Intensity Mapping Experiment, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Green Bank Telescope, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Polarization (waves), Position angle, 01 natural sciences, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Circular polarization
Abstract

We report the first detections of the repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using the 4$-$8 GHz receiver of the Robert C. Byrd Green Bank Telescope with the Breakthrough Listen digital backend. We present the spectral, temporal and polarization properties of 21 bursts detected within the first 60 minutes of a total 6-hour observations. These observations comprise the highest burst density yet reported in the literature, with 18 bursts being detected in the first 30 minutes. A few bursts clearly show temporal sub-structures with distinct spectral properties. These sub-structures superimpose to provide enhanced peak signal-to-noise ratio at higher trial dispersion measures. Broad features occur in $\sim 1$ GHz wide subbands that typically differ in peak frequency between bursts within the band. Finer-scale structures ($\sim 10-50$ MHz) within these bursts are consistent with that expected from Galactic diffractive interstellar scintillation. The bursts exhibit nearly 100% linear polarization, and a large average rotation measure of 9.359$\pm$0.012 $\times$ 10$^{\rm 4}$ rad m$^{\rm -2}$ (in the observer's frame). No circular polarization was found for any burst. We measure an approximately constant polarization position angle in the 13 brightest bursts. The peak flux densities of the reported bursts have average values (0.2$\pm$0.1 Jy), similar to those seen at lower frequencies ($, Accepted for publication in ApJ

Published
2018

31. A decade of transitional millisecond pulsars

Author

Amruta Jaodand, Anne M. Archibald, Jason W. T. Hessels, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Millisecond, History, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, 01 natural sciences, System a, Neutron star, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
Abstract

Transitional millisecond pulsars (tMSPs), which are systems that harbor a pulsar in the throes of the recycling process, have emerged as a new source class since the discovery of the first such system a decade ago. These systems switch between accretion-powered low-mass X-ray binary (LMXB) and rotation-powered radio millisecond pulsar (RMSP) states, and provide exciting avenues to understand the physical processes that spin-up neutron stars to millisecond periods. During the last decade, three tMSPs, as well as a candidate source, have been extensively probed using systematic, multi-wavelength campaigns. Here we review the observational highlights from these campaigns and our general understanding of tMSPs., 4 pages, 2 figures, to appear in Proceedings of IAU Symposium 337: Pulsar Astrophysics - The Next 50 Years

Published
2017

32. Simultaneous Chandra and VLA Observations of the Transitional Millisecond Pulsar PSR J1023+0038: Anti-correlated X-ray and Radio Variability

Author

Anne M. Archibald, Adam T. Deller, Jason W. T. Hessels, James Miller-Jones, Amruta Jaodand, Slavko Bogdanov, Caroline D'Angelo, Alessandro Patruno, Cees Bassa, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Magnetosphere, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Accretion (astrophysics), Black hole, Jansky, Neutron star, Pulsar, Space and Planetary Science, Observatory, Millisecond pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present coordinated Chandra X-ray Observatory and Karl G. Jansky Very Large Array observations of the transitional millisecond pulsar PSR J1023+0038 in its low-luminosity accreting state. The unprecedented five hours of strictly simultaneous X-ray and radio continuum coverage for the first time unambiguously show a highly reproducible, anti-correlated variability pattern. The characteristic switches from the X-ray high mode into a low mode are always accompanied by a radio brightening with duration that closely matches the X-ray low mode interval. This behavior cannot be explained by a canonical inflow/outflow accretion model where the radiated emission and the jet luminosity are powered by, and positively correlated with, the available accretion energy. We interpret this phenomenology as alternating episodes of low-level accretion onto the neutron star during the X-ray high mode that are interrupted by rapid ejections of plasma by the active rotation-powered pulsar, possibly initiated by a reconfiguration of the pulsar magnetosphere, that cause a transition to a less luminous X-ray mode. The observed anti-correlation between radio and X-ray luminosity has an additional consequence: transitional MSPs can make excursions into a region of the radio/X-ray luminosity plane previously thought to be occupied solely by black hole X-ray binary sources. This complicates the use of this luminosity relation to identify candidate black holes, suggesting the need for additional discriminants when attempting to establish the true nature of the accretor., 11 pages, 6 figures; submitted to the Astrophysical Journal

Published
2017

33. Toward an Empirical Theory of Pulsar Emission

Author

Joanna M. Rankin, Joel M. Weisberg, Willem van Straten, Joeri van Leeuwen, Scott M. Ransom, Anne M. Archibald, Ingrid H. Stairs, Jason W. T. Hessels, Dipanjan Mitra, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Flux tube, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Plasma oscillation, 01 natural sciences, Magnetic field, Dipole, Astrophysics - Solar and Stellar Astrophysics, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Polar, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The five-component profile of the 2.7-ms pulsar J0337+1715 appears to exhibit the best example to date of a core/double-cone emission-beam structure in a millisecond pulsar (MSP). Moreover, three other MSPs, the Binary Pulsar B1913+16, B1953+29 and J1022+1001, seem to exhibit core/single-cone profiles. These configurations are remarkable and important because it has not been clear whether MSPs and slow pulsars exhibit similar emission-beam configurations, given that they have considerably smaller magnetospheric sizes and magnetic field strengths. MSPs thus provide an extreme context for studying pulsar radio emission. Particle currents along the magnetic polar flux tube connect processes just above the polar cap through the radio-emission region to the light-cylinder and the external environment. In slow pulsars radio-emission heights are typically about 500 km around where the magnetic field is nearly dipolar, and estimates of the physical conditions there point to radiation below the plasma frequency and emission from charged solitons by the curvature process. We are able to estimate emission heights for the four MSPs and carry out a similar estimation of physical conditions in their much lower emission regions. We find strong evidence that MSPs also radiate by curvature emission from charged solitons., 14 pages, published in ApJ

Published
2017
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34. A Search for Fast Radio Bursts with the GBNCC Pulsar Survey

Author

Mallory S. E. Roberts, J. van Leeuwen, V. M. Kaspi, Anne M. Archibald, Scott M. Ransom, V. I. Kondratiev, Kevin Stovall, Ryan S. Lynch, Duncan R. Lorimer, Kaustubh Rajwade, A. Josephy, Megan E. DeCesar, David L. Kaplan, P. Chawla, C. Karako-Argaman, Lina Levin, Maura McLaughlin, Ingrid H. Stairs, Jason W. T. Hessels, Joseph K. Swiggum, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, Flux distribution, education.field_of_study, 010308 nuclear & particles physics, Scattering, Canadian Hydrogen Intensity Mapping Experiment, statistical [methods], Monte Carlo method, Bandwidth (signal processing), Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, general [pulsars], 01 natural sciences, surveys, Pulsar, Space and Planetary Science, 0103 physical sciences, data analysis [methods], education, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics
Abstract

We report on a search for Fast Radio Bursts (FRBs) with the Green Bank Northern Celestial Cap (GBNCC) Pulsar Survey at 350 MHz. Pointings amounting to a total on-sky time of 61 days were searched to a DM of 3000 pc cm$^{-3}$ while the rest (23 days; 29% of the total time) were searched to a DM of 500 pc cm$^{-3}$. No FRBs were detected in the pointings observed through May 2016. We estimate a 95% confidence upper limit on the FRB rate of $3.6\times 10^3$ FRBs sky$^{-1}$ day$^{-1}$ above a peak flux density of 0.63 Jy at 350 MHz for an intrinsic pulse width of 5 ms. We place constraints on the spectral index $\alpha$ by running simulations for different astrophysical scenarios and cumulative flux density distributions. The non-detection with GBNCC is consistent with the 1.4-GHz rate reported for the Parkes surveys for $\alpha > +0.35 $ in the absence of scattering and free-free absorption and $\alpha > -0.3$ in the presence of scattering, for a Euclidean flux distribution. The constraints imply that FRBs exhibit either a flat spectrum or a spectral turnover at frequencies above 400 MHz. These constraints also allow estimation of the number of bursts that can be detected with current and upcoming surveys. We predict that CHIME may detect anywhere from several to $\sim$50 FRBs a day (depending on model assumptions), making it well suited for interesting constraints on spectral index, the log $N$-log $S$ slope and pulse profile evolution across its bandwidth (400-800 MHz)., Comment: 18 pages, 10 figures, Accepted for publication in ApJ

Published
2017
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35. Conquering systematics in the timing of the pulsar triple system J0337+1715

Author

Duncan R. Lorimer, Scott Ransom, N. V. Gusinskaia, Anne M. Archibald, Ingrid H. Stairs, Jason W. T. Hessels, Ryan S. Lynch, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, History, 010308 nuclear & particles physics, General relativity, Astrophysics::High Energy Astrophysical Phenomena, Binary number, White dwarf, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Computer Science Applications, Education, Numerical integration, Gravitation, Radio telescope, Neutron star, Pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

PSR J0337+1715 is a millisecond radio pulsar in a hierarchical stellar triple system containing two white dwarfs. The pulsar orbits the inner white dwarf every 1.6 days. In turn, this inner binary system orbits the outer white dwarf every 327 days. The gravitational influence of the outer white dwarf strongly accelerates the inner binary, making this system an excellent laboratory in which to test the strong equivalence principle (SEP) of general relativity – especially because the neutron star has significant gravitational self-binding energy. This system has been intensively monitored using three radio telescopes: Arecibo, Green Bank and Westerbork. Using the more than 25000 pulse times of arrival (TOAs) collected to date, we have modeled the system using direct 3-body numerical integration. Here we present our efforts to quantify the effects of systematics in the TOAs and timing residuals, which can limit the precision to which we can test the SEP in this system. In this work we describe Fourier-based techniques that we apply to the residuals in order to isolate the effects of systematics that could masquerade as an SEP violation. We also demonstrate that tidal effects are insignificant in the modeling.

Published
2017
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36. emcee v3: A Python ensemble sampling toolkit for affine-invariant MCMC

Author

David W. Hogg, Will M. Farr, Miguel de Val-Borro, Daniel Foreman-Mackey, Joe Zuntz, Peter K. G. Williams, Andrew Nelson, Tobias Erhardt, Oriol Abril Pla, Anne M. Archibald, Ilya Pashchenko, Manodeep Sinha, and Jeremy S. Sanders

Subjects
FOS: Computer and information sciences, 0303 health sciences, Programming language, Probabilistic logic, FOS: Physical sciences, Markov chain Monte Carlo, Python (programming language), computer.software_genre, Statistics - Computation, 01 natural sciences, 03 medical and health sciences, symbols.namesake, 0103 physical sciences, symbols, Affine invariant, Graphical model, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, computer, Implementation, Computation (stat.CO), 030304 developmental biology, computer.programming_language
Abstract

emcee is a Python library implementing a class of affine-invariant ensemble samplers for Markov chain Monte Carlo (MCMC). This package has been widely applied to probabilistic modeling problems in astrophysics where it was originally published, with some applications in other fields. When it was first released in 2012, the interface implemented in emcee was fundamentally different from the MCMC libraries that were popular at the time, such as PyMC, because it was specifically designed to work with "black box" models instead of structured graphical models. This has been a popular interface for applications in astrophysics because it is often non-trivial to implement realistic physics within the modeling frameworks required by other libraries. Since emcee's release, other libraries have been developed with similar interfaces, such as dynesty (Speagle 2019). The version 3.0 release of emcee is the first major release of the library in about 6 years and it includes a full re-write of the computational backend, several commonly requested features, and a set of new "move" implementations., Comment: Published in the Journal for Open Source Software

Published
2019
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37. Timing Observations of PSR J1023+0038 During a Low-Mass X-ray Binary State

Author

Amruta Jaodand, Alessandro Patruno, Anne M. Archibald, Adam T. Deller, Jason W. T. Hessels, Slavko Bogdanov, Caroline D'Angelo, and Cees Bassa

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Angular momentum, Accretion (meteorology), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Neutron star, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Low Mass, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Transitional millisecond pulsars (tMSPs) switch, on roughly multi-year timescales, between rotation-powered radio millisecond pulsar (RMSP) and accretion-powered low-mass X-ray binary (LMXB) states. The tMSPs have raised several questions related to the nature of accretion flow in their LMXB state and the mechanism that causes the state switch. The discovery of coherent X-ray pulsations from PSR J1023+0038 (while in the LMXB state) provides us with the first opportunity to perform timing observations and to compare the neutron star's spin variation during this state to the measured spin-down in the RMSP state. Whereas the X-ray pulsations in the LMXB state likely indicate that some material is accreting onto the neutron star's magnetic polar caps, radio continuum observations indicate the presence of an outflow. The fraction of the inflowing material being ejected is not clear, but it may be much larger than that reaching the neutron star's surface. Timing observations can measure the total torque on the neutron star. We have phase-connected nine XMM-Newton observations of PSR J1023+0038 over the last 2.5 years of the LMXB state to establish a precise measurement of spin evolution. We find that the average spin-down rate as an LMXB is 26.8+/-0.4% faster than the rate (-2.39x10^-15 Hz s-1) determined during the RMSP state. This shows that negative angular momentum contributions (dipolar magnetic braking and outflow) exceed positive ones (accreted material), and suggests that the pulsar wind continues to operate at a largely unmodified level. We discuss implications of this tight observational constraint in the context of possible accretion models., 19 pages, 7 Figures, Accepted for publication in the Astrophysical Journal

Published
2016

38. Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013

Author

Alejandro Garcia, Michael E Zucker, Courtney R. Epstein, Roman Schnabel, S. Mastrogiovanni, J. E. Brau, A. A. van Veggel, Efim A. Khazanov, G. Ballardin, B. D. Lackey, L. Pinard, J. L. Willis, D. J. McManus, Howard Pan, Denis Martynov, R. Robie, Marco Bazzan, Kipp Cannon, M. Steinke, A. Kutynia, F. Clara, D. Meacher, M. Fays, B. M. Levine, J. Flanigan, A. Cumming, Aaron Buikema, C. C. Wipf, E. J. King, M. J. Cowart, V. Dolique, Federico Ferrini, R. S. Ottens, G. Vajente, P. Kumar, Q. Chu, W. Z. Korth, K. Siellez, C. Baune, Laura Cadonati, E. Genin, F. Baldaccini, Evan Ochsner, D. Ugolini, N. Letendre, B. R. Hall, A. J. Weinstein, A. Di Lieto, V. Boschi, G. Mazzolo, M. Landry, S. Ascenzi, M. Lormand, J. Bergman, H. J. Bulten, J. P. Zendri, Michael Kramer, B. Mours, G. McIntyre, P. Thomas, Z. Patrick, V. Malvezzi, David Jones, Erik Katsavounidis, Vladimir B. Braginsky, H. Vahlbruch, T. Chalermsongsak, Alessandro Bertolini, K. Riles, H. Middleton, M. Weinert, F. Fidecaro, G. M. Guidi, M. Barsuglia, A. Grant, N. Mazumder, M. Prijatelj, T. Dal Canton, J. Warner, H. N. Isa, M. J. Hart, C. J. Bell, N. A. Robertson, L. Kleybolte, J. C. Driggers, P. Puppo, A. W. Muir, C. L. Mueller, C. C. Arceneaux, R. Cavalieri, H. Rew, R. Passaquieti, A. Perreca, Marco Cavaglia, S. J. Chamberlin, M. Vasúth, G. Dojcinoski, Francesco Pannarale, H. Qi, R. F. Cardoso, J. K. Blackburn, A. Sawadsky, Timothy MacDonald, Leo Singer, T. Isogai, M. Branchesi, A. K. Srivastava, Robinjeet Singh, E. Chassande-Mottin, J. C. Batch, Jonathan Cripe, Sheila Rowan, G. A. Prodi, R. DeSalvo, K. Mason, Márton Tápai, David Jonathan Hofman, E. C. Ferreira, E. A. Huerta, B. Behnke, R. Birney, Susan M. Scott, I. Khan, Y. Wang, G. M. Harry, D. Rosińska, K. Venkateswara, Aaron Berndsen, Patrice Hello, Laleh Sadeghian, V. P. Mitrofanov, S. T. Countryman, A. W. Heptonstall, Vivien Raymond, Peter R. Saulson, L. Cerboni Baiardi, T. D. Abbott, O. Puncken, A. Ford, V. Necula, Surabhi Sachdev, Christopher J. Moore, Daniele Trifirò, Chad Hanna, K. A. Hodge, Bala R. Iyer, J. M. Gonzalez Castro, Yuri Levin, S. McCormick, O. V. Palashov, Sean T. McWilliams, M. Merzougui, Carl-Johan Haster, C. Aulbert, F. Piergiovanni, Chang-Hwan Lee, G. Cerretani, L. Trozzo, S. Mirshekari, M. C. Araya, Sanjeev Dhurandhar, Jason W. T. Hessels, Albert Lazzarini, Y. Minenkov, E. G. Thomas, A. Basti, P. G. Murray, Todd Adams, R. Goetz, F. Frasconi, Tarun Souradeep, Liam Cunningham, R. M. Martin, Robert Stone, A. Di Virgilio, A. R. Williamson, W. Del Pozzo, P. F. Cohadon, H. Heitmann, Roy Williams, G. Pillant, V. V. Frolov, L. Rolland, W. D. Vousden, Albrecht Rüdiger, J. Oberling, A. Singhal, L. Matone, Fabrizio Barone, Haocun Yu, Fiodor Sorrentino, B. K. Berger, M. Davier, M. J. Yap, Samaya Nissanke, Jens Birch, Z. Frei, T. Penucci, M. Ast, O. E. S. Sauter, F. Mezzani, Fabien Kéfélian, J. H. Hough, M. Mohan, K. G. Arun, T. Huynh-Dinh, J. Luo, K. Haris, Chunglee Kim, Xing-Jiang Zhu, V. Sequino, M. S. Shahriar, S. Huang, P. Bacon, Daniel E. Holz, S. Márka, D. Barta, J. S. Kissel, V. I. Kondratiev, B. J. J. Slagmolen, Joshua Yablon, D. Passuello, N. Man, Fan Zhang, Collin D. Capano, D. J. Vine, J. R. Palamos, T. Z. Summerscales, Stanislav Babak, D. Day, Namjun Kim, J.-D. Fournier, M. H. Wimmer, K. Kokeyama, J. J. Hacker, Philip F. Hopkins, William Yam, L. Wallace, S. Chung, S. Farinon, M. Constancio, Duncan A. Brown, T. Sadecki, A. Królak, R. Frey, Kenneth A. Strain, Jimin George, M. Sieniawska, A. Moggi, Kevin M. Ryan, H. J. Jang, Gregory Ashton, Fabio Marchesoni, Maria Ilaria Del Principe, B. Patricelli, F. Garufi, C. M. Reed, M. Korobko, G. D. Meadors, Margaret Millhouse, S. Grunewald, M. Agathos, S. G. Gaonkar, D. Bersanetti, S. R. Morriss, Riccardo Bassiri, Magnus Manske, E. Maros, Douglas R. Cook, A. Viceré, Yi Chen, M. E. Normandin, G. Bogaert, Haixing Miao, K. Haughian, J. Eichholz, B. C. Stephens, Marc Favata, V. M. Kaspi, Roger Jones, V. J. Roma, Michele Zanolin, Michael Pürrer, Serena Vinciguerra, F. Nocera, D. J. White, I. Fiori, D. J. Hosken, C. Zhao, E. Coccia, C. Graef, B. A. Weaver, J. G. Rollins, Kyungmin Kim, D. D. Brown, B. O'Reilly, T. J. Massinger, T. Vo, O. J. Piccinni, S. B. Coughlin, S. L. Danilishin, M. Shaltev, O. Bock, L. Di Fiore, James G. Bartlett, K. L. Dooley, G. Mendell, T. Di Girolamo, L.-W. Wei, N. van Bakel, Lisa Barsotti, R. J. G. Jonker, I. Kowalska, S. Kaufer, Eric Oelker, M. Boer, J. B. Kanner, Rainer Weiss, S. Penn, D. Schuette, A. Giazotto, R. Pedurand, Benno Willke, Joonghan Kim, A. Grado, Fredrick A. Jenet, P. Shawhan, Alberto Vecchio, L. Prokhorov, I. Ferrante, C. Cahillane, Will M. Farr, Subhabrata Mitra, R. W. P. Drever, E. A. Quintero, J. Hennig, G. L. Mansell, Jessica Steinlechner, A. Neunzert, Duncan R. Lorimer, Nam-Gyu Kim, S. A. Usman, G. D. Hammond, D. H. Shoemaker, M. Kasprzack, P. Couvares, P. Charlton, Kejia Lee, P. Brockill, G. Vedovato, D. B. Kozak, Tyson Littenberg, T. B. Edo, Gavin Davies, A. Lenon, B. L. Pearlstone, M. Ducrot, Archisman Ghosh, X. F. Wang, Rebecca Fisher, Maura McLaughlin, H. Fehrmann, W. W. Johnson, G. P. Newton, M. Fyffe, Michael L. Gorodetsky, T. Westphal, Ryan Lynch, M. Heurs, S. S. Premachandra, A. Masserot, V. Dattilo, Tejinder Kaur, Edwin J. Son, K. Kawabe, D. Huet, S. H. Huttner, F. Cleva, Marie-Anne Bizouard, S. Walsh, A. Sheperd, Maximiliano Isi, Zifan Zhou, M. Montani, Alessandra Buonanno, R. Metzdorff, Nancy Aggarwal, Zahoor Ali Khan, V. Fafone, Andrew Melatos, Kendall Ackley, R. K. Nayak, D. Mendoza-Gandara, J-Y. Vinet, B. Shapiro, Reed Essick, R. Everett, Jan Harms, D. Talukder, C. V. Torres, S. M. Aston, C. Vorvick, I. W. Harry, Satyanarayan Ray Pitambar Mohapatra, Viswanath Bavigadda, A. Sevigny, P. B. Graff, I. A. Bilenko, J. L. Wright, Alessandra Corsi, David J. Ottaway, A. Paoli, A. R. Wade, R. S. Lynch, G. Kuehn, C. M. Mow-Lowry, Sergey P. Vyatchanin, A. Idrisy, M. Yvert, Lionel Martellini, Kazuhiro Agatsuma, F. Magaña-Sandoval, R. M. Magee, Peter Fritschel, Gabriela Gonzalez, Benjamin William Allen, P. J. Sutton, P. Bojtos, David Blair, Karsten Danzmann, J. Betzwieser, M. Gosselin, Alex B. Nielsen, J. H. Romie, G. Serna, Stefan Hild, Y. Ma, P. Chawla, S. Kandhasamy, B. Sorazu, T. Etzel, Hua Wang, S. E. Hollitt, Vicky Kalogera, G. Lunsford, D. B. Kelley, C. Palomba, J.-M. Isac, Heinz-Bernd Eggenstein, Zhihui Du, V. Predoi, I. W. Martin, L. Rei, M. Masso-Reid, Mark Hannam, I. Dave, Adam A. Libson, M. Fletcher, B. Hughey, Evan Goetz, Michael W. Coughlin, A. L. Stuver, J. E. Lord, M. Mageswaran, C. C. Yancey, A. Ain, B. F. Whiting, J. Casanueva Diaz, Lei Zhang, P. Schale, E. Cuoco, A. Gupta, M. Tonelli, Larry R. Price, John Miller, Leopoldo Milano, Slawomir Gras, C. Bond, Nergis Mavalvala, Sascha Husa, A. Gennai, H. P. Daveloza, C. Van Den Broeck, Arielle N. Walker, Jordan Camp, P. Wessels, T. T. Nguyen, C. S. Unnikrishnan, Lloyd Paul Aiello, R. Douglas, F. J. Raab, David E. McClelland, Scott M. Ransom, B. C. Pant, N. Indik, Andrea Chincarini, T. Prestegard, S. S. Eikenberry, M. S. Kehl, A. Post, Yanxi Zhang, M. Bejger, Hartmut Grote, F. Marion, E. J. Daw, J. Schmidt, Kevin Stovall, C. Krueger, Rosa Poggiani, V. Germain, V. Frey, Jong H. Chow, Paolo Addesso, K. D. Giardina, G. Losurdo, L. Conti, Ingrid H. Stairs, M. Vardaro, A. Pasqualetti, A. Mytidis, A. Pele, P. Raffai, R. Chakraborty, D. M. Macleod, S. E. Gossan, G. Greco, L. E. Wade, J. S. Lange, B. L. Swinkels, Neil J. Cornish, Evan Keane, G. Bergmann, J. Hanks, N. A. Strauss, Timothy A Welborn, V. Tiwari, K. Gill, Walter Winkler, Jiayi Qin, A. Singer, M. C. Díaz, Samuel Deléglise, L. P. Dartez, C. Pankow, P. M. Meyers, Hyun Lee, M. D. Rohr, J. Calderón Bustillo, Jerome Degallaix, Y. Setyawati, C. Casentini, Sebastian Khan, F. Carbognani, E. O. Lebigot, T. Denker, Christopher P. L. Berry, A. D. Silva, H. J. Pletsch, Enrico Calloni, G. Traylor, Thomas Corbitt, L. Salconi, C. A. Costa, L. R. Cominsky, R. Gustafson, M. P. Thirugnanasambandam, N. Straniero, G. Wu, F. Robinet, S. Meshkov, Seog Oh, W. G. Anderson, G. Cella, Giacomo Ciani, B. P. Abbott, E. K. Gustafson, Meng Wang, D.B. DeBra, A. Bisht, M. Leonardi, S. E. Zuraw, Sourav Ghosh, Imre Bartos, V. Quetschke, Bangalore Suryanarayana Sathyaprakash, Martin M. Fejer, J. R. Smith, R. Bork, L. van der Schaaf, S. A. Pai, Cody Messick, Yann Bouffanais, A. Bohe, A. C. Green, Fausto Acernese, Fumiko Kawazoe, D. Moraru, A. S. Markosyan, Madeline Wade, P. Leaci, A. Colla, Harald Lück, D. Verkindt, J. N. Marx, Vuk Mandic, Gianpietro Cagnoli, László Á. Gergely, Tania Regimbau, M. M. Hanke, Barry C. Barish, Christian D. Ott, K. Nedkova, S. Tiwari, S. B. Anderson, M. Cho, Paul J. Groot, M. Zevin, A. Staley, L. Zangrando, Sung-Po Chao, John A. Clark, S. Jawahar, T. Theeg, Ben Farr, V. Re, E. A. Houston, X. Guo, Matthew Evans, S. Vass, A. Glaefke, C. Tomlinson, J. D. Lough, R. Coyne, Mi Zhang, C. Gray, G. H. Ogin, Soma Mukherjee, S. C. McGuire, J. F. Read, M. K. Gupta, J. G. Martinez, John Veitch, S. Di Pace, J. C. Barayoga, D. Nolting, M. Neri, J. A. Giaime, S. Raja, S. E. Strigin, Y. M. Kim, R. De Rosa, Ruslan Vaulin, David B. Tanner, F. Jiménez-Forteza, H. Radkins, N. S. Darman, N. Arnaud, Maggie Tse, Christophe Collette, Ho-Gyu Lee, K. A. Thorne, C. Messenger, Fabrice Matichard, R. Inta, Aviral Singh, P. J. King, W. Kells, S. Klimenko, M. MacInnis, M. Mantovani, H. R. Paris, L. Kuo, H. Yamamoto, E. Capocasa, Thibaut Jacqmin, C. I. Torrie, A. Mata, P. Rapagnani, D. R. Ingram, A. Bozzi, B. A. Boom, S. D'Antonio, A. Allocca, M. Brinkmann, F. Vetrano, J. Zweizig, D. C. Coyne, E. L. Merilh, K. Izumi, M. C. Tringali, I. Nardecchia, Anne M. Archibald, Sebastian Steinlechner, Andreas Freise, Vincenzo Pierro, Paul D. Lasky, S. G. Crowder, J. van Leeuwen, I. Maksimovic, A. Rocchi, D. V. Voss, R. L. Ward, G. Hemming, Matthew Pitkin, D. Stiles, N. Gehrels, N. A. Gordon, Xavier Siemens, P. J. Veitch, Andrew Lundgren, M. Factourovich, S. Koley, S. Leake, A. Schönbeck, T. P. Downes, R. L. Savage, A. S. Bell, D. Pascucci, Mallory S. E. Roberts, J. R. Sanders, J. Prasad, W. Katzman, F. Y. Khalili, M. Saleem, Carlos Cepeda, Robert J. McCarthy, H. Fair, M. Pichot, Andrea Taracchini, J. V. van Heijningen, David Coward, Sheon Chua, R. Bonnand, N. Leroy, M. Granata, Marek Szczepanczyk, Minchuan Zhou, G. Wang, C. Bradaschia, P. Oppermann, Linqing Wen, Ik Siong Heng, K. N. Mukund, Steven Bloemen, Jonathan R. Gair, M. Pedraza, H. A. G. Gabbard, M. Chan, Ettore Majorana, Christie A. McPhee, W. Engels, S. M. Koehlenbeck, Eric Thrane, Maria Alessandra Papa, F. Cavalier, A. Zadro.zny, C. Michel, G. Valdes, S. E. Dwyer, David Keitel, G. Islas, G. Debreczeni, Chia-Liang Cheng, Antoine Heidmann, Gleb Romanov, Nicholas Smith, Qi Fang, Rui Miguel Faisca Rodrigues Pereira, D. Töyrä, N. A. Lockerbie, H. Overmier, T. Hardwick, D. Steinmeyer, P. Ehrens, F. Travasso, Blake Moore, Sarah Caudill, R. Quitzow-James, R. Day, F. Ohme, V. B. Adya, William Parker, Z. Shao, M. Razzano, A. Nitz, S. Banaszak, D. Simakov, E. Schreiber, G. Kang, A. Pal-Singh, M. Was, A. L. Miller, B. Sandeen, M. C. Edwards, C. Bogan, J. Hinojosa, Thomas Dent, Vladimir Dergachev, S. Karki, D. Sellers, James Whelan, M. Bitossi, K. Wette, F. Martelli, Karan Jani, Suvadeep Bose, Gijs Nelemans, Graham Woan, P. Astone, Larne Pekowsky, Robert L. Byer, V. Kondrashov, I. Di Palma, Stuart Reid, A. Samajdar, P. Ajith, M. Punturo, H. Vocca, J. Meidam, John J. Oh, Timothy Evans, Eugeniy E. Mikhailov, R. Gouaty, Z. Márka, E. D. Hall, Jolien D. E. Creighton, S. Caride, Arunava Mukherjee, R. Mittleman, Nelson Christensen, Riccardo Sturani, M. T. Hartman, V. Kringel, Rory Smith, C. Adams, R. M. Blair, D. Sigg, S. W. Ballmer, K. Holt, D. M. Shoemaker, G. Gemme, V. Sandberg, Bernard F. Schutz, D. S. Rabeling, Li Ju, H. Wittel, Daniel A. Shaddock, M. Phelps, T. T. Fricke, C. V. Kalaghatgi, J. Hanson, D. Hoak, Michelle E. Walker, G. Moreno, D. Sentenac, M. Di Giovanni, K. E. Gushwa, Matthew Heintze, Rocco Romano, J. S. Key, John D. Scott, D. L. Kinzel, R. A. Mercer, Tomasz Bulik, M. Turconi, Patrick Brady, J. S. Areeda, D. Fiorucci, Richard J. Oram, François Bondu, Guido Mueller, Joseph D. Romano, J. Ming, A. Conte, T. A. Callister, N. Kijbunchoo, Michael Thomas, Sebastien Biscans, David Murphy, A. Effler, A. L. Lombardi, M. Drago, Guenakh Mitselmakher, J. R. Leong, G. Stratta, Jesper Munch, M. van Beuzekom, C. C. Buchanan, M. Haney, P. Popolizio, Koji Arai, H. S. Cho, P. Fulda, Kasem Mossavi, Jade Powell, V. Mangano, Achamveedu Gopakumar, M. De Laurentis, E. J. Sanchez, S. E. Barclay, David H. Reitze, Yi-Ming Hu, Tjonnie G. F. Li, Eric Howell, F. Ricci, S. Leavey, L. K. Nuttall, J. Boyles, M. R. Abernathy, G. Billingsley, A. M. Sergeev, D. Buskulic, J. Logue, B. Lantz, C. Affeldt, R. Taylor, R. T. DeRosa, T. P. Bodiya, R. M. S. Schofield, M. Oliver, Benjamin J. Owen, J. F. J. van den Brand, M. Tacca, Martin Hendry, E. Cesarini, Kieran Craig, K. V. Tokmakov, Antonios Kontos, Debnandini Mukherjee, J. O'Dell, Junwei Cao, M. Lorenzini, S. Doravari, Samuele Cortese, Innocenzo M. Pinto, A. F. Brooks, S. Privitera, L. Sammut, S. E. Whitcomb, V. Loriette, Francesco Salemi, Rana X. Adhikari, Christelle Lesvigne-Buy, Jessica McIver, P. A. Altin, B. L. Wells, Alexander Khalaidovski, B. Machenschalk, F. Donovan, A. Chiummo, Luca Gammaitoni, D. Barker, B. Sassolas, R. Kennedy, D. C. Vander-Hyde, C. Karako-Argaman, M. K. M. Bader, A. Brillet, D. Tuyenbayev, Christopher M. Biwer, S. Frasca, Tristan Briant, G. Gaur, Stephen Fairhurst, Carl Blair, Archana Pai, F. Paoletti, P. Ruggi, A. Mullavey, L. Sun, Xiaohui Fan, Richard O'Shaughnessy, B. Barr, Malik Rakhmanov, J. Worden, P. T. Baker, N. M. Brown, Roland Schilling, Swetha Bhagwat, S. P. Tarabrin, L. Naticchioni, Salvatore Vitale, Richard J. Abbott, A. L. Urban, R. Flaminio, J.-P. Coulon, Odylio D. Aguiar, H. S. Chen, László Gondán, Angus Cherry, C. Lazzaro, Patricia Schmidt, V. Brisson, A. M. Sintes, P. Aufmuth, Chandra Kant Mishra, R. Bhandare, Piotr Jaranowski, California Institute of Technology, Louisiana State University, Fisciano, Complesso Universitario di Monte S. Angelo, University of Florida, LIGO Livingston Observatory, CNRS/IN2P3, University of Sannio at Benevento, Max-Planck-Institut für Gravitationsphysik, Science Park, Massachusetts Institute of Technology, Instituto Nacional de Pesquisas Espaciais, Gran Sasso Science Institute, Sezione di Roma Tor Vergata, Inter-University Centre for Astronomy and Astrophysics, Tata Institute of Fundamental Research, University of Wisconsin-Milwaukee, Leibniz Universität Hannover, Università di Pisa, Sezione di Pisa, Australian National University, University of Mississippi, California State University Fullerton, Université Paris-Saclay, Chennai Mathematical Institute, Università di Roma Tor Vergata, University of Southampton, Universität Hamburg, Sezione di Roma, Sorbonne Paris Cité, Montana State University, Università di Perugia, Sezione di Perugia, European Gravitational Observatory (EGO), Syracuse University, University of Glasgow, LIGO Hanford Observatory, RMKI, Columbia University, Stanford University, Dipartimento di Fisica e Astronomia, Sezione di Padova, CAMK-PAN, University of Birmingham, Università degli Studi di Genova, Sezione di Genova, RRCAT, Lomonosov Moscow State University, University of the West of Scotland, University of Western Australia, Radboud University Nijmegen, Observatoire Côte d'Azur, Lendulet Astrophysics Research Group, Université de Rennes 1, Washington State University, Università degli Studi di Urbino Carlo Bo, Sezione di Firenze, University of Oregon, Collège de France, Astronomical Observatory Warsaw University, VU University Amsterdam, University of Maryland, Georgia Institute of Technology, Université Claude Bernard Lyon 1, IEEC, NASA/Goddard Space Flight Center, University of Toronto, Tsinghua University, University of Michigan, National Tsing Hua University, Charles Sturt University, University of Chicago, Caltech CaRT, Korea Institute of Science and Technology Information, Carleton College, Università di Roma la Sapienza, University of Brussels, Sonoma State University, Texas Tech University, Cardiff University, University of Minnesota, University of Melbourne, University of Texas Rio Grande Valley, University of Sheffield, Dipartimento di Fisica, Trento Institute for Fundamental Physics and Applications, Montclair State University, Pennsylvania State University, National Astronomical Observatory of Japan, University of Edinburgh, Indian Institute of Technology, Institute for Plasma Research, University of Szeged, Embry-Riddle Aeronautical University, Osservatorio Astronomico di Capodimonte, American University, University of Massachusetts-Amherst, University of Adelaide, West Virginia University, University of Biał Ystok, University of Strathclyde, CET Campus, Northwestern University, Institute of Applied Physics, Pusan National University, Hanyang University, NCBJ, IM-PAN, Rochester Institute of Technology, Monash University, Seoul National University, University of Alabama in Huntsville, CNRS, Southern University and A and M College, College of William and Mary, Universidade Estadual Paulista (UNESP), University of Cambridge, IISER-Kolkata, HSIC, Whitman College, National Institute for Mathematical Sciences, Université de Lyon, Hobart and William Smith Colleges, University of Zielona Góra, Andrews University, Università di Siena, Trinity University, University of Washington, Kenyon College, Abilene Christian University, Netherlands Institute for Radio Astronomy, University of British Columbia, Western Kentucky University, McGill University, Ohio State University, University of Amsterdam, Jodrell Bank Observatory, Lebedev Physical Institute, Max Planck Institute for Radio Astronomy, University of Manchester, National Radio Astronomy Observatory, University of Virginia, Inc., University of New Mexico, Colorado State University, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des matériaux avancés (LMA), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Science and Engineering Research Board, Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada, Alfred P. Sloan Foundation, Carnegie Trust for the Universities of Scotland, Science and Technology Facilities Council, Ontario Ministry of Economic Development and Innovation, Ministerio de Economía y Competitividad, Scottish Funding Council, Seventh Framework Programme, Industry Canada, Council of Scientific and Industrial Research, Australian Research Council, Royal Society, Narodowe Centrum Nauki, National Aeronautics and Space Administration, 617199, European Research Council, Centre National de la Recherche Scientifique, Max-Planck-Gesellschaft, Department of Science and Technology, Ministry of Science and Technology, Research Corporation for Science Advancement, National Science Foundation, Leverhulme Trust, David and Lucile Packard Foundation, Országos Tudományos Kutatási Alapprogramok, State of Niedersachsen, International Science Linkages, Conselleria d’Economia i Competitivitat and Conselleria d’Educaci, Universitats of the Govern de les Illes Balears, Lyon Institute of Origins, Brazilian Ministry of Science, Technology, and Innovation, Ministry of Human Resource Development, Scottish Universities Physics Alliance, Stichting voor Fundamenteel Onderzoek der Materie, Istituto Nazionale di Fisica Nucleare, National Research Foundation of Korea, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, LIGO, VIRGO, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules ( LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Savoie Mont Blanc ( USMB [Université de Savoie] [Université de Chambéry] ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de l'Accélérateur Linéaire ( LAL ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux ( ARTEMIS ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Institut de Physique de Rennes ( IPR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire des matériaux avancés ( LMA ), Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), The LIGO Scientific Collaboration, The Virgo Collaboration, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), (Astro)-Particles Physics, Abbott, B. P., Abbott, R., Abbott, T. D., Abernathy, M. R., Acernese, F., Ackley, K., Adams, C., Adams, T., Addesso, P., Adhikari, R. X., Adya, V. B., Affeldt, C., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O. D., Aiello, L., Ain, A., Ajith, P., Allen, B., Allocca, A., Altin, P. A., Anderson, S. B., Anderson, W. G., Arai, K., Araya, M. C., Arceneaux, C. C., Areeda, J. S., Arnaud, N., Arun, K. G., Ascenzi, S., Ashton, G., Ast, M., Aston, S. M., Astone, P., Aufmuth, P., Aulbert, C., Babak, S., Bacon, P., Bader, M. K. M., Baker, P. T., Baldaccini, F., Ballardin, G., Ballmer, S. W., Barayoga, J. C., Barclay, S. E., Barish, B. C., Barker, D., Barone, F., Barr, B., Barsotti, L., Barsuglia, M., Barta, D., Bartlett, J., Bartos, I., Bassiri, R., Basti, A., Batch, J. C., Baune, C., Bavigadda, V., Bazzan, M., Behnke, B., Bejger, M., Bell, A. S., Bell, C. J., Berger, B. K., Bergman, J., Bergmann, G., Berry, C. P. L., Bersanetti, D., Bertolini, A., Betzwieser, J., Bhagwat, S., Bhandare, R., Bilenko, I. A., Billingsley, G., Birch, J., Birney, R., Biscans, S., Bisht, A., Bitossi, M., Biwer, C., Bizouard, M. A., Blackburn, J. K., Blair, C. D., Blair, D. G., Blair, R. M., Bloemen, S., Bock, O., Bodiya, T. P., Boer, M., Bogaert, G., Bogan, C., Bohe, A., Bojtos, P., Bond, C., Bondu, F., Bonnand, R., Boom, B. A., Bork, R., Boschi, V., Bose, S., Bouffanais, Y., Bozzi, A., Bradaschia, C., Brady, P. R., Braginsky, V. B., Branchesi, M., Brau, J. E., Briant, T., Brillet, A., Brinkmann, M., Brisson, V., Brockill, P., Brooks, A. F., Brown, D. A., Brown, D. D., Brown, N. M., Buchanan, C. C., Buikema, A., Bulik, T., Bulten, H. J., Buonanno, A., Buskulic, D., Buy, C., Byer, R. L., Cadonati, L., Cagnoli, G., Cahillane, C., Calderón Bustillo, J., Callister, T., Calloni, Enrico, Camp, J. B., Cannon, K. C., Cao, J., Capano, C. D., Capocasa, E., Carbognani, F., Caride, S., Casanueva Diaz, J., Casentini, C., Caudill, S., Cavaglià, M., Cavalier, F., Cavalieri, R., Cella, G., Cepeda, C. B., Cerboni Baiardi, L., Cerretani, G., Cesarini, E., Chakraborty, R., Chalermsongsak, T., Chamberlin, S. J., Chan, M., Chao, S., Charlton, P., Chassande Mottin, E., Chen, H. Y., Chen, Y., Cheng, C., Chincarini, A., Chiummo, A., Cho, H. S., Cho, M., Chow, J. H., Christensen, N., Chu, Q., Chua, S., Chung, S., Ciani, G., Clara, F., Clark, J. A., Cleva, F., Coccia, E., Cohadon, P. F., Colla, A., Collette, C. G., Cominsky, L., Constancio, M., Conte, A., Conti, L., Cook, D., Corbitt, T. R., Cornish, N., Corsi, A., Cortese, S., Costa, C. A., Coughlin, M. W., Coughlin, S. B., Coulon, J. P., Countryman, S. T., Couvares, P., Coward, D. M., Cowart, M. J., Coyne, D. C., Coyne, R., Craig, K., Creighton, J. D. E., Cripe, J., Crowder, S. G., Cumming, A., Cunningham, L., Cuoco, E., Dal Canton, T., Danilishin, S. L., D'Antonio, S., Danzmann, K., Darman, N. S., Dattilo, V., Dave, I., Daveloza, H. P., Davier, M., Davies, G. S., Daw, E. J., Day, R., Debra, D., Debreczeni, G., Degallaix, J., DE LAURENTIS, Martina, Deléglise, S., Del Pozzo, W., Denker, T., Dent, T., Dergachev, V., DE ROSA, Rosario, Derosa, R. T., Desalvo, R., Dhurandhar, S., Díaz, M. C., Di Fiore, L., Di Giovanni, M., DI GIROLAMO, Tristano, Di Lieto, A., Di Pace, S., Di Palma, I., Di Virgilio, A., Dojcinoski, G., Dolique, V., Donovan, F., Dooley, K. L., Doravari, S., Douglas, R., Downes, T. P., Drago, M., Drever, R. W. P., Driggers, J. C., Du, Z., Ducrot, M., Dwyer, S. E., Edo, T. B., Edwards, M. C., Effler, A., Eggenstein, H. B., Ehrens, P., Eichholz, J., Eikenberry, S. S., Engels, W., Essick, R. C., Etzel, T., Evans, M., Evans, T. M., Everett, R., Factourovich, M., Fafone, V., Fair, H., Fairhurst, S., Fan, X., Fang, Q., Farinon, S., Farr, B., Farr, W. M., Favata, M., Fays, M., Fehrmann, H., Fejer, M. M., Ferrante, I., Ferreira, E. C., Ferrini, F., Fidecaro, F., Fiori, I., Fiorucci, D., Fisher, R. P., Flaminio, R., Fletcher, M., Fournier, J. D., Frasca, S., Frasconi, F., Frei, Z., Freise, A., Frey, R., Frey, V., Fricke, T. T., Fritschel, P., Frolov, V. V., Fulda, P., Fyffe, M., Gabbard, H. A. G., Gair, J. R., Gammaitoni, L., Gaonkar, S. G., Garufi, Fabio, Gaur, G., Gehrels, N., Gemme, G., Genin, E., Gennai, A., George, J., Gergely, L., Germain, V., Ghosh, Archisman, Ghosh, S., Giaime, J. A., Giardina, K. D., Giazotto, A., Gill, K., Glaefke, A., Goetz, E., Goetz, R., Gondan, L., González, G., Gonzalez Castro, J. M., Gopakumar, A., Gordon, N. A., Gorodetsky, M. L., Gossan, S. E., Gosselin, M., Gouaty, R., Grado, A., Graef, C., Graff, P. B., Granata, M., Grant, A., Gras, S., Gray, C., Greco, G., Green, A. C., Groot, P., Grote, H., Grunewald, S., Guidi, G. M., Guo, X., Gupta, A., Gupta, M. K., Gushwa, K. E., Gustafson, E. K., Gustafson, R., Hacker, J. J., Hall, B. R., Hall, E. D., Hammond, G., Haney, M., Hanke, M. M., Hanks, J., Hanna, C., Hannam, M. D., Hanson, J., Hardwick, T., Harms, J., Harry, G. M., Harry, I. W., Hart, M. J., Hartman, M. T., Haster, C. J., Haughian, K., Heidmann, A., Heintze, M. C., Heitmann, H., Hello, P., Hemming, G., Hendry, M., Heng, I. S., Hennig, J., Heptonstall, A. W., Heurs, M., Hild, S., Hoak, D., Hodge, K. A., Hofman, D., Hollitt, S. E., Holt, K., Holz, D. E., Hopkins, P., Hosken, D. J., Hough, J., Houston, E. A., Howell, E. J., Hu, Y. M., Huang, S., Huerta, E. A., Huet, D., Hughey, B., Husa, S., Huttner, S. H., Huynh Dinh, T., Idrisy, A., Indik, N., Ingram, D. R., Inta, R., Isa, H. N., Isac, J. M., Isi, M., Islas, G., Isogai, T., Iyer, B. R., Izumi, K., Jacqmin, T., Jang, H., Jani, K., Jaranowski, P., Jawahar, S., Jiménez Forteza, F., Johnson, W. W., Jones, D. I., Jones, R., Jonker, R. J. G., Ju, L., Haris, K., Kalaghatgi, C. V., Kalogera, V., Kandhasamy, S., Kang, G., Kanner, J. B., Karki, S., Kasprzack, M., Katsavounidis, E., Katzman, W., Kaufer, S., Kaur, T., Kawabe, K., Kawazoe, F., Kéfélian, F., Kehl, M. S., Keitel, D., Kelley, D. B., Kells, W., Kennedy, R., Key, J. S., Khalaidovski, A., Khalili, F. Y., Khan, I., Khan, S., Khan, Z., Khazanov, E. A., Kijbunchoo, N., Kim, Chunglee, Kim, J., Kim, K., Kim, Nam Gyu, Kim, Namjun, Kim, Y. M., King, E. J., King, P. J., Kinzel, D. L., Kissel, J. S., Kleybolte, L., Klimenko, S., Koehlenbeck, S. M., Kokeyama, K., Koley, S., Kondrashov, V., Kontos, A., Korobko, M., Korth, W. Z., Kowalska, I., Kozak, D. B., Kringel, V., Królak, A., Krueger, C., Kuehn, G., Kumar, P., Kuo, L., Kutynia, A., Lackey, B. D., Landry, M., Lange, J., Lantz, B., Lasky, P. D., Lazzarini, A., Lazzaro, C., Leaci, P., Leavey, S., Lebigot, E. O., Lee, C. H., Lee, H. K., Lee, H. M., Lee, K., Lenon, A., Leonardi, M., Leong, J. R., Leroy, N., Letendre, N., Levin, Y., Levine, B. M., Li, T. G. F., Libson, A., Littenberg, T. B., Lockerbie, N. A., Logue, J., Lombardi, A. L., Lord, J. E., Lorenzini, M., Loriette, V., Lormand, M., Losurdo, G., Lough, J. D., Lück, H., Lundgren, A. P., Luo, J., Lynch, R., Ma, Y., Macdonald, T., Machenschalk, B., Macinnis, M., Macleod, D. M., Magaña Sandoval, F., Magee, R. M., Mageswaran, M., Majorana, E., Maksimovic, I., Malvezzi, V., Man, N., Mandic, V., Mangano, V., Mansell, G. L., Manske, M., Mantovani, M., Marchesoni, F., Marion, F., Márka, S., Márka, Z., Markosyan, A. S., Maros, E., Martelli, F., Martellini, L., Martin, I. W., Martin, R. M., Martynov, D. V., Marx, J. N., Mason, K., Masserot, A., Massinger, T. J., Masso Reid, M., Mastrogiovanni, S., Matichard, F., Matone, L., Mavalvala, N., Mazumder, N., Mazzolo, G., Mccarthy, R., Mcclelland, D. E., Mccormick, S., Mcguire, S. C., Mcintyre, G., Mciver, J., Mcmanus, D. J., Mcwilliams, S. T., Meacher, D., Meadors, G. D., Meidam, J., Melatos, A., Mendell, G., Mendoza Gandara, D., Mercer, R. A., Merilh, E. L., Merzougui, M., Meshkov, S., Messenger, C., Messick, C., Metzdorff, R., Meyers, P. M., Mezzani, F., Miao, H., Michel, C., Middleton, H., Mikhailov, E. E., Milano, Leopoldo, Miller, A. L., Miller, J., Millhouse, M., Minenkov, Y., Ming, J., Mirshekari, S., Mishra, C., Mitra, S., Mitrofanov, V. P., Mitselmakher, G., Mittleman, R., Moggi, A., Mohan, M., Mohapatra, S. R. P., Montani, M., Moore, B. C., Moore, C. J., Moraru, D., Moreno, G., Morriss, S. R., Mossavi, K., Mours, B., Mow Lowry, C. M., Mueller, C. L., Mueller, G., Muir, A. W., Mukherjee, Arunava, Mukherjee, D., Mukherjee, S., Mukund, K. N., Mullavey, A., Munch, J., Murphy, D. J., Murray, P. G., Mytidis, A., Nardecchia, I., Naticchioni, L., Nayak, R. K., Necula, V., Nedkova, K., Nelemans, G., Neri, M., Neunzert, A., Newton, G., Nguyen, T. T., Nielsen, A. B., Nissanke, S., Nitz, A., Nocera, F., Nolting, D., Normandin, M. E. N., Nuttall, L. K., Oberling, J., Ochsner, E., O'Dell, J., Oelker, E., Ogin, G. H., Oh, J. J., Oh, S. H., Ohme, F., Oliver, M., Oppermann, P., Oram, Richard J., O'Reilly, B., O'Shaughnessy, R., Ott, C. D., Ottaway, D. J., Ottens, R. S., Overmier, H., Owen, B. J., Pai, A., Pai, S. A., Palamos, J. R., Palashov, O., Palomba, C., Pal Singh, A., Pan, H., Pankow, C., Pannarale, F., Pant, B. C., Paoletti, F., Paoli, A., Papa, M. A., Paris, H. R., Parker, W., Pascucci, D., Pasqualetti, A., Passaquieti, R., Passuello, D., Patricelli, B., Patrick, Z., Pearlstone, B. L., Pedraza, M., Pedurand, R., Pekowsky, L., Pele, A., Penn, S., Pereira, R., Perreca, A., Phelps, M., Piccinni, O. J., Pichot, M., Piergiovanni, F., Pierro, V., Pillant, G., Pinard, L., Pinto, I. M., Pitkin, M., Pletsch, H. J., Poggiani, R., Popolizio, P., Post, A., Powell, J., Prasad, J., Predoi, V., Premachandra, S. S., Prestegard, T., Price, L. R., Prijatelj, M., Principe, M., Privitera, S., Prodi, G. A., Prokhorov, L., Puncken, O., Punturo, M., Puppo, P., Pürrer, M., Qi, H., Qin, J., Quetschke, V., Quintero, E. A., Quitzow James, R., Raab, F. J., Rabeling, D. S., Radkins, H., Raffai, P., Raja, S., Rakhmanov, M., Rapagnani, P., Raymond, V., Razzano, M., Re, V., Read, J., Reed, C. M., Regimbau, T., Rei, L., Reid, S., Reitze, D. H., Rew, H., Ricci, F., Riles, K., Robertson, N. A., Robie, R., Robinet, F., Rocchi, A., Rolland, L., Rollins, J. G., Roma, V. J., Romano, J. D., Romano, R., Romanov, G., Romie, J. H., Rosińska, D., Rowan, S., Rüdiger, A., Ruggi, P., Ryan, K., Sachdev, S., Sadecki, T., Sadeghian, L., Salconi, L., Saleem, M., Salemi, F., Samajdar, A., Sammut, L., Sanchez, E. J., Sandberg, V., Sandeen, B., Sanders, J. R., Sassolas, B., Sathyaprakash, B. S., Saulson, P. R., Sauter, O. E. S., Savage, R. L., Sawadsky, A., Schale, P., Schilling, R., Schmidt, J., Schmidt, P., Schnabel, R., Schofield, R. M. S., Schönbeck, A., Schreiber, E., Schuette, D., Schutz, B. F., Scott, J., Scott, S. M., Sellers, D., Sentenac, D., Sequino, V., Sergeev, A., Serna, G., Setyawati, Y., Sevigny, A., Shaddock, D. A., Shahriar, M. S., Shaltev, M., Shao, Z., Shapiro, B., Shawhan, P., Sheperd, A., Shoemaker, D. H., Shoemaker, D. 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Mikhailov, E. .e., Milano, L., Miller, A. .l., Mitrofanov, V. .p., Mohapatra, S. .r. .p., MONTANI, MATTEO, Moore, B. .c., Moore, C. .j., Morriss, S. .r., Mow Lowry, C. .m., Mueller, C. .l., Muir, A. .w., Mukund, K. .n., Murphy, D. .j., Murray, P. .g., Nayak, R. .k., Nguyen, T. .t., Nielsen, A. .b., Normandin, M. .e. .n., Nuttall, L. .k., O’Dell, J., Ogin, G. .h., Oh, J. .j., Oh, S. .h., O’Reilly, B., O’Shaughnessy, R., Ott, C. .d., Ottaway, D. .j., Ottens, R. .s., Owen, B. .j., Pai, S. .a., Palamos, J. .r., Pant, B. .c., Papa, M. .a., Paris, H. .r., Pearlstone, B. .l., Piccinni, O. .j., PIERGIOVANNI, FRANCESCO, Pinto, I. .m., Pletsch, H. .j., Premachandra, S. .s., Price, L. .r., Prodi, G. .a., Quintero, E. .a., Raab, F. .j., Rabeling, D. .s., Reed, C. .m., Reitze, D. .h., Robertson, N. .a., Rollins, J. .g., Roma, V. .j., Romano, J. .d., Romie, J. .h., Sanchez, E. .j., Sanders, J. .r., Sathyaprakash, B. .s., Saulson, P. .r., Sauter, O. .e. .s., Savage, R. .l., Schofield, R. .m. .s., Schutz, B. .f., Scott, S. .m., Shaddock, D. .a., Shahriar, M. .s., Shoemaker, D. .h., Shoemaker, D. .m., Silva, A. .d., Singer, L. .p., Sintes, A. .m., Slagmolen, B. .j. .j., Smith, J. .r., Smith, N. .d., Smith, R. .j. .e., Son, E. .j., Srivastava, A. .k., Stephens, B. .c., Strain, K. .a., STRATTA, MARIA GIULIANA, Strauss, N. .a., Stuver, A. .l., Summerscales, T. .z., Sutton, P. .j., Swinkels, B. .l., Szczepańczyk, M. .j., Tanner, D. .b., Tarabrin, S. .p., Thirugnanasambandam, M. .p., Thomas, E. .g., Thorne, K. .a., Tokmakov, K. .v., Torres, C. .v., Torrie, C. .i., Tringali, M. .c., Unnikrishnan, C. .s., Urban, A. .l., Usman, S. .a., van Bakel, N., van Beuzekom, M., van den Brand, J. .f. .j., Vander Hyde, D. .c., van der Schaaf, L., van Heijningen, J. .v., van Veggel, A. .a., Veitch, P. .j., VETRANO, FLAVIO, VICERE', ANDREA, Vine, D. .j., Voss, D. .v., Vousden, W. .d., Vyatchanin, S. .p., Wade, A. .r., Wade, L. .e., Ward, R. .l., Weinstein, A. .j., Whelan, J. .t., Whitcomb, S. .e., White, D. .j., Whiting, B. .f., Williams, R. .d., Williamson, A. .r., Willis, J. .l., Wimmer, M. .h., Wipf, C. .c., Wright, J. .l., Yancey, C. .c., Yap, M. .j., Zhu, X. .j., Zucker, M. .e., Zuraw, S. .e., Archibald, A. .m., Cardoso, R. .f., Dartez, L. .p., Epstein, C. .r., Ford, A. .j., Hessels, J. .w. .t., Jenet, F. .a., Kaspi, V. .m., Keane, E. .f., Kondratiev, V. .i., Lynch, R. .s., Martinez, J. .g., Mclaughlin, M. .a., Mcphee, C. .a., Roberts, M. .s. .e., Rohr, M. .d. .w., Stairs, I. .h., van Leeuwen, J., Walker, A. .n., Wells, B. .l., CALTECH, Louisiana State Univ, Univ Salerno, Ist Nazl Fis Nucl, Univ Florida, LIGO Livingston Observ, Univ Savoie Mont Blanc, Univ Sannio Benevento, Max Planck Inst Gravitat Phys, NIKHEF H, MIT, Inst Nacl Pesquisas Espaciais, Inter Univ Ctr Astron & Astrophys, Tata Inst Fundamental Res, Univ Wisconsin, Leibniz Univ Hannover, Univ Pisa, Australian Natl Univ, Univ Mississippi, Calif State Univ Fullerton, Univ Paris Saclay, Chennai Math Inst, Univ Roma Tor Vergata, Univ Southampton, Univ Hamburg, Universidade de São Paulo (USP), Montana State Univ, Univ Perugia, EGO, Syracuse Univ, Univ Glasgow, LIGO Hanford Observ, Columbia Univ, Stanford Univ, Univ Padua, CAMK PAN, Univ Birmingham, Univ Genoa, Lomonosov Moscow State Univ, Univ West Scotland, Univ Western Australia, Radboud Univ Nijmegen, Univ Cote Azur, MTA Eotvos Univ, Univ Rennes 1, Washington State Univ, Univ Urbino Carlo Bo, Univ Oregon, Univ Paris 06, Warsaw Univ, Vrije Univ Amsterdam, Univ Maryland, Georgia Inst Technol, CNRS IN2P3, Univ Lyon 1, Univ Illes Balears, Univ Naples Federico II, NASA, Univ Toronto, Tsinghua Univ, Univ Michigan, Natl Tsing Hua Univ, Charles Sturt Univ, Univ Chicago, Korea Inst Sci & Technol Informat, Carleton Coll, Univ Roma La Sapienza, Univ Brussels, Sonoma State Univ, Texas Tech Univ, Cardiff Univ, Univ Minnesota, Univ Melbourne, Univ Texas Rio Grande Valley, Univ Sheffield, Univ Trento, Montclair State Univ, Penn State Univ, Natl Astron Observ Japan, Univ Edinburgh, Indian Inst Technol, Inst Plasma Res, Univ Szeged, Embry Riddle Aeronaut Univ, Amer Univ, Univ Massachusetts, Univ Adelaide, W Virginia Univ, Univ Bialystok, Univ Strathclyde, IISER TVM, Northwestern Univ, Inst Appl Phys, Pusan Natl Univ, Hanyang Univ, IM PAN, Rochester Inst Technol, Monash Univ, Seoul Natl Univ, Univ Alabama, Univ Camerino, Southern Univ, A&M Coll, Coll William & Mary, Universidade Estadual Paulista (Unesp), Univ Cambridge, IISER Kolkata, Rutherford Appleton Lab, Whitman Coll, Natl Inst Math Sci, Univ Lyon, Hobart & William Smith Coll, Univ Zielona Gora, Andrews Univ, Univ Siena, Trinity Univ, Univ Washington, Kenyon Coll, Abilene Christian Univ, ASTRON, Univ British Columbia, Western Kentucky Univ, McGill Univ, Ohio State Univ, Univ Amsterdam, SKA Org, Lebedev Phys Inst, Max Planck Inst Radioastron, Univ Manchester, Natl Radio Astron Observ, Univ Virginia, Eureka Sci Inc, Univ New Mexico, Colorado State Univ, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Radio Transients, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Nuclear and High Energy Physics, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, detection, FOS: Physical sciences, Gravitational Wave, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Coincidence, GAMMA-RAY BURST, ENERGY, Pulsar, Settore FIS/05 - Astronomia e Astrofisica, Gravitational Waves, Radio Transients, 0103 physical sciences, Binary star, coincidence, 010303 astronomy & astrophysics, QC, QB, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gravitational Waves, PLASMA, 010308 nuclear & particles physics, Gravitational wave, ORIGIN, Settore FIS/01 - Fisica Sperimentale, Green Bank Telescope, Astrophysics::Instrumentation and Methods for Astrophysics, [ PHYS.ASTR.HE ] Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], PULSARS, LIGO, PULSES, Neutron star, Physics and Astronomy, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, GW, Gamma-ray burst, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Copyright © 2016 American Physical Society and reproduced in accordance with the publisher copyright policy, We present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, the current analysis serves as a prototype for similar future searches using more sensitive second-generation interferometers.

Published
2016
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39. Search for Optical Pulsations in PSR J0337+1715

Author

J. C. van Eyken, G. Ulbricht, Seth R. Meeker, M. J. Strader, David L. Kaplan, Paul Szypryt, Anne M. Archibald, Bruce Bumble, Christopher Stoughton, Benjamin A. Mazin, and Alex B. Walter

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Pulsar planet, Astrophysics::Instrumentation and Methods for Astrophysics, White dwarf, Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, law.invention, Telescope, Neutron star, Pulsar, Space and Planetary Science, Observatory, Millisecond pulsar, law, 0103 physical sciences, Magnitude (astronomy), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010306 general physics, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We report on a search for optical pulsations from PSR J0337+1715 at its observed radio pulse period. PSR J0337+1715 is a millisecond pulsar (2.7 ms spin period) in a triple hierarchical system with two white dwarfs, and has a known optical counterpart with g-band magnitude 18. The observations were done with the Array Camera for Optical to Near-IR Spectrophotometry (ARCONS) at the 200" Hale telescope at Palomar Observatory. No significant pulsations were found in the range 4000-11000 angstroms, and we can limit pulsed emission in g-band to be fainter than 25 mag., Comment: 4 pages, 2 figures, accepted to MNRAS

Published
2016

40. Conquering systematics in the timing of the pulsar triple system J0337+1715: Towards a unique and robust test of the strong equivalence principle

Author

N. V. Gusinskaia, Ryan S. Lynch, Scott Ransom, Anne M. Archibald, Ingrid H. Stairs, Jason W. T. Hessels, and Duncan R. Lorimer

Subjects
Physics, General relativity, Astrophysics::High Energy Astrophysical Phenomena, White dwarf, Binary number, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Numerical integration, Gravitation, Radio telescope, Neutron star, Pulsar, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

PSR J0337+1715 is a millisecond radio pulsar in a hierarchical stellar triple system containing two white dwarfs. The pulsar orbits the inner white dwarf every 1.6 days. In turn, this inner binary system orbits the outer white dwarf every 327 days. The gravitational influence of the outer white dwarf strongly accelerates the inner binary, making this system an excellent laboratory in which to test the strong equivalence principle (SEP) of general relativity – especially because the neutron star has significant gravitational self-binding energy. This system has been intensively monitored using three radio telescopes: Arecibo, Green Bank and Westerbork. Using the more than 25000 pulse times of arrival (TOAs) collected to date, we have modeled the system using direct 3-body numerical integration. Here we present our efforts to quantify the effects of systematics in the TOAs and timing residuals, which can limit the precision to which we can test the SEP in this system. In this work we describe Fourier-based techniques that we apply to the residuals in order to isolate the effects of systematics that could masquerade as an SEP violation. We also demonstrate that tidal effects are insignificant in the modeling.

Published
2017
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41. X-ray variability and evidence for pulsations from the unique radio pulsar/X-ray binary transition object FIRST J102347.6+003841

Author

Jason W. T. Hessels, Anne M. Archibald, Scott M. Ransom, Slavko Bogdanov, Ingrid H. Stairs, Victoria M. Kaspi, Maura McLaughlin, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Neutron star, Stars, Astrophysics - Solar and Stellar Astrophysics, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Binary star, Astrophysics::Solar and Stellar Astrophysics, Roche lobe, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, X-ray pulsar
Abstract

We report on observations of the unusual neutron-star binary system FIRST J102347.6+003841 carried out using the XMM-Newton satellite. This system consists of a radio millisecond pulsar in an 0.198-day orbit with a ~0.2 solar-mass Roche-lobe-filling companion, and appears to have had an accretion disk in 2001. We observe a hard power-law spectrum (\Gamma = 1.26(4)) with a possible thermal component, and orbital variability in X-ray flux and possibly hardness of the X-rays. We also detect probable pulsations at the pulsar period (single-trial significance ~4.5 sigma from an 11(2)% modulation), which would make this the first system in which both orbital and rotational X-ray pulsations are detected. We interpret the emission as a combination of X-rays from the pulsar itself and from a shock where material overflowing the companion meets the pulsar wind. The similarity of this X-ray emission to that seen from other millisecond pulsar binary systems, in particular 47 Tuc W (PSR J0024-7204W) and PSR J1740-5340, suggests that they may also undergo disk episodes similar to that seen in J1023 in 2001., Comment: 14 pages, 5 figures, 1 table; accepted to ApJ

Published
2010
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42. SDSS J102347.6+003841: A MILLISECOND RADIO PULSAR BINARY THAT HAD A HOT DISK DURING 2000-2001

Author

Ingrid H. Stairs, John R. Thorstensen, Anne M. Archibald, Scott M. Ransom, Zhongxiang Wang, Duncan R. Lorimer, and Victoria M. Kaspi

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Brown dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Orbital period, 01 natural sciences, Spectral line, Neutron star, Stars, Pulsar, Space and Planetary Science, Millisecond pulsar, Sky, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common
Abstract

The Sloan Digital Sky Survey (SDSS) source J102347.6+003841 was recently revealed to be a binary 1.69 millisecond radio pulsar with a 4.75 hr orbital period and a ~0.2 M_sun companion. Here we analyze the SDSS spectrum of the source in detail. The spectrum was taken on 2001 February 1, when the source was in a bright state and showed broad, double-peaked hydrogen and helium lines -- dramatically different from the G-type absorption spectrum seen from 2003 onward. The lines are consistent with emission from a disk around the compact primary. We derive properties of the disk by fitting the SDSS continuum with a simple disk model, and find a temperature range of 2000--34000 K from the outer to inner edge of the disk. The disk inner and outer radii were approximately 10^9 and 5.7x10^10 cm, respectively. These results further emphasize the unique feature of the source: it is likely a system at the end of its transition from an X-ray binary to a recycled radio pulsar. The disk mass is estimated to have been ~10^23 g, most of which would have been lost due to pulsar wind ablation (or due to the propeller effect if the disk had extended inside the light cylinder of the pulsar) before the final disk disruption event. The system could undergo repeated episodes of disk formation. Close monitoring of the source is needed to catch the system in its bright state again, so that this unusual example of a pulsar-disk interaction can be studied in much finer detail, Comment: 8 pages, 5 figures. Accepted for publication in ApJ

Published
2009
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43. No Detectable Radio Emission from the Magnetar‐Like Pulsar in Kes 75

Author

Victoria M. Kaspi, Anne M. Archibald, Maura McLaughlin, and Margaret A. Livingstone

Subjects
Physics, 010504 meteorology & atmospheric sciences, Astrophysics (astro-ph), Green Bank Telescope, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Magnetar, 01 natural sciences, law.invention, Magnetic field, Telescope, Dipole, Pulsar, Space and Planetary Science, law, 0103 physical sciences, Supernova remnant, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

The rotation-powered pulsar PSR J1846-0258 in the supernova remnant Kes 75 was recently shown to have exhibited magnetar-like X-ray bursts in mid-2006. Radio emission has not yet been observed from this source, but other magnetar-like sources have exhibited transient radio emission following X-ray bursts. We report on a deep 1.9 GHz radio observation of PSR J1846-0258 with the 100-m Green Bank Telescope in late 2007 designed to search for radio pulsations or bursts from this target. We have also analyzed three shorter serendipitous 1.4 GHz radio observations of the source taken with the 64-m Parkes telescope during the 2006 bursting period. We detected no radio emission from PSR J1846-0258 in either the Green Bank or Parkes datasets. We place an upper limit of 4.9 \mu Jy on coherent pulsed emission from PSR J1846-0258 based on the 2007 November 2 observation, and an upper limit of 27 \mu Jy around the time of the X-ray bursts. Serendipitously, we observed radio pulses from the nearby RRAT J1846-02, and place a 3\sigma confidence level upper limit on its period derivative of 1.7 * 10^{-13}, implying its surface dipole magnetic field is less than 2.6 * 10^{13} G., Comment: 15 pages, 2 figures, submitted to ApJ

Published
2008
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44. The Long‐Term Radiative Evolution of Anomalous X‐Ray Pulsar 1E 2259+586 After Its 2002 Outburst

Author

Peter M. Woods, Anne M. Archibald, Victoria M. Kaspi, Weiwei Zhu, Rim Dib, and Fotis P. Gavriil

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Flux, Astronomy, Astronomy and Astrophysics, Astrophysics, Magnetar, Power law, Anomalous X-ray pulsar, Neutron star, Pulsar, Space and Planetary Science, Radiative transfer, X-ray pulsar
Abstract

We present an analysis of five XMM-Newton observations of the anomalous X-ray pulsar (AXP) 1E 2259+586 taken in 2004 and 2005 during its relaxation following its 2002 outburst. We compare these data with those of five previous XMM-Newton observations taken in 2002 and 2003, and find the observed flux decay is well described by a power law of index –0.69 ± 0.03. As of mid-2005, the source may still have been brighter than preoutburst, and was certainly hotter. We find a strong correlation between hardness and flux, as seen in other AXPs. We discuss the implications of these results for the magnetar model.

Published
2008
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45. Radio Imaging Observations of PSR J1023+0038 in an LMXB State

Author

Zsolt Paragi, Anne M. Archibald, Jason W. T. Hessels, Adam T. Deller, George Heald, Alessandro Patruno, James Miller-Jones, J. Moldon, N. Vilchez, Kapteyn Astronomical Institute, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Brightness, European VLBI Network, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Compact star, 01 natural sciences, Jansky, X-rays: binaries, accretion, Millisecond pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, accretion disks, Astronomy and Astrophysics, LOFAR, Accretion (astrophysics), 3. Good health, Neutron star, Astrophysics - Solar and Stellar Astrophysics, pulsars: individual: PSR J1023+0038, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, radio continuum: stars
Abstract

The transitional millisecond pulsar binary system PSR J1023+0038 re-entered an accreting state in 2013 June, in which it bears many similarities to low-mass X-ray binaries (LMXBs) in quiescence or near-quiescence. At a distance of just 1.37 kpc, PSR J1023+0038 offers an unsurpassed ability to study low-level accretion onto a highly-magnetized compact object. We have monitored PSR J1023+0038 intensively using radio imaging with the Karl G. Jansky Very Large Array, the European VLBI Network and LOFAR, seeing rapidly variable, flat spectrum emission that persists over a period of 6 months. The flat spectrum and variability are indicative of synchrotron emission originating in an outflow from the system, most likely in the form of a compact, partially self-absorbed jet, as is seen in LMXBs at higher accretion rates. The radio brightness, however, greatly exceeds extrapolations made from observations of more vigorously accreting neutron star LMXB systems. We postulate that PSR J1023+0038 is undergoing radiatively inefficient 'propeller-mode' accretion, with the jet carrying away a dominant fraction of the liberated accretion luminosity. We confirm that the enhanced gamma-ray emission seen in PSR J1023+0038 since it re-entered an accreting state has been maintained; the increased gamma-ray emission in this state can also potentially be associated with propeller-mode accretion. Similar accretion modes can be invoked to explain the radio and X-ray properties of the other two known transitional millisecond pulsar systems XSS J12270-4859 and PSR J1824-2452I (M28I), suggesting that radiatively inefficient accretion may be an ubiquitous phenomenon amongst (at least one class of) neutron star binaries at low accretion rates., updated to the version accepted by ApJ (updated references and expanded discussion), 19 pages in emulateapj format, 10 figures, 2 tables

Published
2015

46. Coordinated X-Ray, Ultraviolet, Optical, and Radio Observations of the PSR J1023+0038 System in a Low-mass X-Ray Binary State

Author

Slavko Bogdanov, Gemma H. Janssen, Jason W. T. Hessels, Javier Moldon, Caroline D'Angelo, Ben Stappers, Rudy Wijnands, George Heald, Andrew Lyne, Cees Bassa, Shriharsh P. Tendulkar, Benetge Perera, Zsolt Paragi, Jules P. Halpern, Anne M. Archibald, Alessandro Patruno, Adam T. Deller, Kapteyn Astronomical Institute, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Pulsar planet, X-ray binary, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Binary pulsar, stars: neutron, X-rays: binaries, Pulsar, Millisecond pulsar, pulsars: general, 0103 physical sciences, Binary system, 010306 general physics, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astronomy, Astronomy and Astrophysics, Neutron star, pulsars: individual: PSR J1023+0038, 13. Climate action, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Low Mass
Abstract

The PSR J1023+0038 binary system hosts a neutron star and a low-mass, main-sequence-like star. It switches on year timescales between states as an eclipsing radio millisecond pulsar and a low-mass X-ray binary. We present a multi-wavelength observational campaign of PSR J1023+0038 in its most recent low-mass X-ray binary state. Two long XMM-Newton observations reveal that the system spends ~70% of the time in a $\approx$$3\times10^{33}$ erg/s X-ray luminosity mode, which, as shown in Archibald et al. (2014), exhibits coherent X-ray pulsations. This emission is interspersed with frequent lower flux mode intervals with $\approx$$5\times 10^{32}$ erg/s and sporadic flares reaching up to $\approx$$10^{34}$ erg/s, with neither mode showing significant X-ray pulsations. The switches between the three flux modes occur on timescales of order 10 s. In the UV and optical, we observe occasional intense flares coincident with those observed in X-rays. Our radio timing observations reveal no pulsations at the pulsar period during any of the three X-ray modes, presumably due to complete quenching of the radio emission mechanism by the accretion flow. Radio imaging detects highly variable, flat-spectrum continuum emission from PSR J1023+0038, consistent with an origin in a weak jet-like outflow. Our concurrent X-ray and radio continuum data sets do not exhibit any correlated behavior. The observational evidence we present bears qualitative resemblance to the behavior predicted by some existing propeller and trapped disk accretion models although none can fully account for all aspects of the rich phenomenology of this system., Comment: 24 pages, 15 figures; accepted for publication in the Astrophysical Journal

Published
2015

47. Discovery and Follow-up of Rotating Radio Transients with the Green Bank and LOFAR Telescopes

Author

Anne M. Archibald, Jason W. T. Hessels, Lina Levin, Fredrick A. Jenet, Jason Boyles, Maura McLaughlin, J. van Leeuwen, Scott M. Ransom, X. Siemens, Mallory S. E. Roberts, Ryan S. Lynch, Ingrid H. Stairs, Joseph K. Swiggum, David L. Kaplan, C. Karako-Argaman, E. C. Madsen, V. M. Kaspi, V. I. Kondratiev, Kevin Stovall, Duncan R. Lorimer, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Green Bank Telescope, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, LOFAR, Astrophysics::Cosmology and Extragalactic Astrophysics, Low frequency, 01 natural sciences, Activity spectrum, Pulsar, Space and Planetary Science, 0103 physical sciences, Dispersion (optics), Radio frequency, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Fourier domain
Abstract

We have discovered 21 Rotating Radio Transients (RRATs) in data from the Green Bank Telescope (GBT) 350-MHz Drift-scan and the Green Bank North Celestial Cap pulsar surveys using a new candidate sifting algorithm. RRATs are pulsars with sporadic emission that are detected through their bright single pulses rather than Fourier domain searches. We have developed {\tt RRATtrap}, a single-pulse sifting algorithm that can be integrated into pulsar survey data analysis pipelines in order to find RRATs and Fast Radio Bursts. We have conducted follow-up observations of our newly discovered sources at several radio frequencies using the GBT and Low Frequency Array (LOFAR), yielding improved positions and measurements of their periods, dispersion measures, and burst rates, as well as phase-coherent timing solutions for four of them. The new RRATs have dispersion measures (DMs) ranging from 15 to 97 pc cm$^{-3}$, periods of 240 ms to 3.4 s, and estimated burst rates of 20 to 400 pulses hr$^{-1}$ at 350 MHz. We use this new sample of RRATs to perform statistical comparisons between RRATs and canonical pulsars in order to shed light on the relationship between the two populations. We find that the DM and spatial distributions of the RRATs agree with those of the pulsars found in the same survey. We find evidence that slower pulsars (i.e. $P>200$ ms) are preferentially more likely to emit bright single pulses than are faster pulsars ($P, 18 pages, 13 figures, 5 tables, published in ApJ

Published
2015
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48. Accretion-powered pulsations in an apparently quiescent neutron star binary

Author

Cees Bassa, Anne M. Archibald, Gemma H. Janssen, Caroline D'Angelo, Ben Stappers, Alessandro Patruno, Andrew Lyne, Adam T. Deller, Rudy Wijnands, Jason W. T. Hessels, Slavko Bogdanov, V. M. Kaspi, Shriharsh P. Tendulkar, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Millisecond, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Binary number, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Accretion (astrophysics), Luminosity, Neutron star, Pulsar, Space and Planetary Science, Millisecond pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, X-ray pulsar
Abstract

Accreting millisecond X-ray pulsars are an important subset of low-mass X-ray binaries in which coherent X-ray pulsations can be observed during occasional, bright outbursts (X-ray luminosity $L_X\sim 10^{36}$ erg s$^{-1}$). These pulsations show that matter is being channeled onto the neutron star's magnetic poles. However, such sources spend most of their time in a low-luminosity, quiescent state ($L_X\lesssim 10^{34}$ erg s$^{-1}$), where the nature of the accretion flow onto the neutron star (if any) is not well understood. Here we report that the millisecond pulsar/low-mass X-ray binary transition object PSR J1023+0038 intermittently shows coherent X-ray pulsations at luminosities nearly 100 times fainter than observed in any other accreting millisecond X-ray pulsar. We conclude that in spite of its low luminosity PSR J1023+0038 experiences episodes of channeled accretion, a discovery that challenges existing models for accretion onto magnetized neutron stars., 9 pages, 7 figures, 1 table; accepted in ApJ

Published
2014

49. A state change in the low-mass X-ray binary XSS J12270-4859

Author

Evan Keane, Anne M. Archibald, Gemma H. Janssen, Stephane Corbel, B. Monard, Philip G. Edwards, Jason W. T. Hessels, C. G. Bassa, Slavko Bogdanov, Shriharsh P. Tendulkar, Elizabeth K. Mahony, Ben Stappers, Alessandro Patruno, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Millisecond, Astrophysics::High Energy Astrophysical Phenomena, Pulsar planet, X-ray binary, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, Orbital period, Binary pulsar, Photometry (astronomy), Pulsar, Space and Planetary Science, Millisecond pulsar, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Millisecond radio pulsars acquire their rapid rotation rates through mass and angular momentum transfer in a low-mass X-ray binary system. Recent studies of PSR J1824-2452I and PSR J1023+0038 have observationally demonstrated this link, and they have also shown that such systems can repeatedly transition back-and-forth between the radio millisecond pulsar and low-mass X-ray binary states. This also suggests that a fraction of such systems are not newly born radio millisecond pulsars but are rather suspended in a back-and-forth state switching phase, perhaps for giga-years. XSS J12270-4859 has been previously suggested to be a low-mass X-ray binary, and until recently the only such system to be seen at MeV-GeV energies. We present radio, optical and X-ray observations that offer compelling evidence that XSS J12270-4859 is a low-mass X-ray binary which transitioned to a radio millisecond pulsar state between 2012 November 14 and 2012 December 21. Though radio pulsations remain to be detected, we use optical and X-ray photometry/spectroscopy to show that the system has undergone a sudden dimming and no longer shows evidence for an accretion disk. The optical observations constrain the orbital period to 6.913+-0.002 hr., 7 pages, 3 figures, submitted for publication in MNRAS

Published
2014

50. X-Ray Observations of XSS J12270-4859 in a New Low State: A Transformation to a Disk-free Rotation-powered Pulsar Binary

Author

Anne M. Archibald, Cees Bassa, Slavko Bogdanov, Gemma H. Janssen, Jason W. T. Hessels, Ben Stappers, Alessandro Patruno, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Nebula, Brightness, Astrophysics::High Energy Astrophysical Phenomena, Binary number, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Pulsar, Space and Planetary Science, Millisecond pulsar, Astrophysics - High Energy Astrophysical Phenomena, Phenomenology (particle physics), Galaxy cluster, Order of magnitude, Astrophysics::Galaxy Astrophysics
Abstract

We present XMM-Newton and Chandra observations of the low-mass X-ray binary XSS J12270--4859, which experienced a dramatic decline in optical/X-ray brightness at the end of 2012, indicative of the disappearance of its accretion disk. In this new state, the system exhibits previously absent orbital-phase-dependent, large-amplitude X-ray modulations with a decline in flux at superior conjunction. The X-ray emission remains predominantly non-thermal but with an order of magnitude lower mean luminosity and significantly harder spectrum relative to the previous high flux state. This phenomenology is identical to the behavior of the radio millisecond pulsar binary PSR J1023+0038 in the absence of an accretion disk, where the X-ray emission is produced in an intra-binary shock driven by the pulsar wind. This further demonstrates that XSS J12270-4859 no longer has an accretion disk and has transformed to a full-fledged eclipsing "redback" system that hosts an active rotation-powered millisecond pulsar. There is no evidence for diffuse X-ray emission associated with the binary that may arise due to outflows or a wind nebula. An extended source situated 1.5' from XSS J12270--4859 is unlikely to be associated, and is probably a previously uncatalogued galaxy cluster., Comment: 8 pages, 6 figures; accepted for publication in the Astrophysical Journal

Published
2014
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