Author: "J W McKee" / Language: undetermined - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"J W McKee"' showing total 26 results

Start Over Author "J W McKee" Language undetermined

26 results on '"J W McKee"'

1. Detection of quasi-periodic micro-structure in three millisecond pulsars with the Large European Array for Pulsars

Author: K Liu, J Antoniadis, C G Bassa, S Chen, I Cognard, M Gaikwad, H Hu, J Jang, G H Janssen, R Karuppusamy, M Kramer, K J Lee, R A Main, G Mall, J W McKee, M B Mickaliger, D Perrodin, S A Sanidas, B W Stappers, L Wang, W W Zhu, M Burgay, R Concu, A Corongiu, A Melis, M Pilia, and A Possenti
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Mathematics
Abstract: We report on the detection of quasi-periodic micro-structure in three millisecond pulsars (MSPs), PSRs J1022+1001, J2145-0750 and J1744-1134, using high time resolution data acquired with the Large European Array for Pulsars at a radio frequency of 1.4 GHz. The occurrence rate of quasi-periodic micro-structure is consistent among pulses with different peak flux densities. Using an auto-correlation analysis, we measure the periodicity and width of the micro-structure in these three pulsars. The detected micro-structure from PSRs J1022+1001 and J1744-1134 is often highly linearly polarised. In PSR J1022+1001, the linear polarisation position angles of micro-structure pulses are in general flat with a small degree of variation. Using these results, we further examine the frequency and rotational period dependency of micro-structure properties established in previous work, along with the angular beaming and temporal modulation models that explains the appearance of micro-structure. We also discuss a possible link of micro-structure to the properties of some of the recently discovered fast radio bursts which exhibit a very similar emission morphology., Comment: 8 pages, 6 figures, 1 table, published in MNRAS
Published: 2022

2. Robust parameter estimation from pulsar timing data

Author: A Samajdar, G Shaifullah, A Sesana, J Antoniadis, M Burgay, S Chen, I Cognard, L Guillemot, M Kramer, J W McKee, M B Mickaliger, G Theureau, E Van&nbsp, derundefined Wateren, Samajdar, A, Shaifullah, G, Sesana, A, Antoniadis, J, Burgay, M, Chen, S, Cognard, I, Guillemot, L, Kramer, M, W McKee, J, B Mickaliger, M, Theureau, G, Van&nbsp, E, and Wateren, D
Subjects: Space and Planetary Science, pulsars: general, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, General Relativity and Quantum Cosmology (gr-qc), gravitational wave, methods: data analysi, General Relativity and Quantum Cosmology
Abstract: Recently, global pulsar timing arrays have released results from searching for a nano-Hertz gravitational wave background signal. Although there has not been any definite evidence of the presence of such a signal in residuals of pulsar timing data yet, with more and improved data in future, a statistically significant detection is expected to be made. Stochastic algorithms are used to sample a very large parameter space to infer results from data. In this paper, we attempt to rule out effects arising from the stochasticity of the sampler in the inference process. We compare different configurations of nested samplers and the more commonly used markov chain monte carlo method to sample the pulsar timing array parameter space and account for times taken by the different samplers on same data. Although we obtain consistent results on parameters from different sampling algorithms, we propose two different samplers for robustness checks on data in the future to account for cross-checks between sampling methods as well as realistic run-times., Comment: 8 pages, 5 figures, 4 tables
Published: 2022

3. The CHIME Pulsar Project: System Overview

Author: A. Renard, Paul Demorest, Laura Newburgh, B. W. Meyers, J. R. Shaw, A. E. Sikora, Ingrid H. Stairs, T. L. Landecker, M. A. Dobbs, Mandana Amiri, N. T. Denman, Scott M. Ransom, Calvin Leung, Jing Luo, A. Naidu, Cherry Ng, C. Brar, Victoria M. Kaspi, C. M. Tan, K. Vanderlinde, J. W. McKee, I. Tretyakov, H. Wang, Xin Wang, M. Fandino, C. Patel, Hsiu-Hsien Lin, F. Q. Dong, Alex S. Hill, Kiyoshi Masui, C. Höfer, Emmanuel Fonseca, J. F. Cliche, P. J. Boyle, Mark Halpern, Kevin Bandura, D. Cubranic, Daniele Michilli, J. Mena-Parra, Shriharsh P. Tendulkar, P. Scholz, Deborah C. Good, T. Pinsonneault-Marotte, and Kathryn Crowter
Subjects: astronomy data analysis, Physics, astronomical instrumentation, pulsar timing method, 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, radio astronomy, 01 natural sciences, Astronomical instrumentation, Pulsar, Space and Planetary Science, 0103 physical sciences, astronomy data acquisition, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), radio pulsars, Radio astronomy
Abstract: We present the design, implementation and performance of a digital backend constructed for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) that uses accelerated computing to observe radio pulsars and transient radio sources. When operating, the CHIME correlator outputs 10 independent streams of beamformed data for the CHIME/Pulsar backend that digitally track specified celestial positions. Each of these independent streams are processed by the CHIME/Pulsar backend system which can coherently dedisperse, in real-time, up to dispersion measure values of 2500 pc/cm$^{-3}$ . The tracking beams and real-time analysis system are autonomously controlled by a priority-based algorithm that schedules both known sources and positions of interest for observation with observing cadences as small as one day. Given the distribution of known pulsars and radio-transient sources, the CHIME/Pulsar system can monitor up to 900 positions once per sidereal day and observe all sources with declinations greater than $-20^\circ$ once every $\sim$2 weeks. We also discuss the science program enabled through the current modes of data acquisition for CHIME/Pulsar that centers on timing and searching experiments., Comment: 18 pages, 9 figures, 1 table. Submitted to ApJS
Published: 2020
Full Text: View/download PDF

4. A pulsar-based time-scale from the International Pulsar Timing Array

Author: Sourav Chatterjee, Daniel J. Reardon, Ismaël Cognard, Gemma H. Janssen, Sarah Burke-Spolaor, Zaven Arzoumanian, Michael T. Lam, Kejia Lee, Michael Kramer, Benetge Perera, J. B. Wang, L. Guo, Renée Spiewak, Ryan Shannon, David J. Nice, Richard N. Manchester, N. D. R. Bhat, D. Matsakis, E. Graikou, Joseph Simon, Ingrid H. Stairs, R. N. Caballero, Shi Dai, Matthew Bailes, Christopher J. Russell, Alberto Sesana, Robert D. Ferdman, Lucas Guillemot, Delphine Perrodin, Xing-Jiang Zhu, Andrew Lyne, Chiara M. F. Mingarelli, C. G. Bassa, Benjamin Stappers, A. Brazier, R. van Haasteren, Timothy T. Pennucci, J. W. McKee, Yue-Fei Wang, Maura McLaughlin, Michael Keith, L. Toomey, Matthew Kerr, William A. Coles, Timothy Dolch, Stefan Oslowski, M. L. Tong, Stephen Taylor, D. J. Champion, Kang Liu, S. A. Sanidas, George Hobbs, J. K. Swiggum, Gregory Desvignes, Gilles Theureau, A. Possenti, T. J. W. Lazio, R. S. Lynch, G. Shaifullah, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Hobbs, G, Guo, L, Caballero, R, Coles, W, Lee, K, Manchester, R, Reardon, D, Matsakis, D, Tong, M, Arzoumanian, Z, Bailes, M, Bassa, C, Bhat, N, Brazier, A, Burke-Spolaor, S, Champion, D, Chatterjee, S, Cognard, I, Dai, S, Desvignes, G, Dolch, T, Ferdman, R, Graikou, E, Guillemot, L, Janssen, G, Keith, M, Kerr, M, Kramer, M, Lam, M, Liu, K, Lyne, A, Lazio, T, Lynch, R, Mckee, J, Mclaughlin, M, Mingarelli, C, Nice, D, Osłowski, S, Pennucci, T, Perera, B, Perrodin, D, Possenti, A, Russell, C, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Simon, J, Spiewak, R, Stairs, I, Stappers, B, Swiggum, J, Taylor, S, Theureau, G, Toomey, L, van Haasteren, R, Wang, J, Wang, Y, Zhu, X, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), ITA, USA, GBR, FRA, DEU, AUS, CAN, NLD, CHN, and HUN
Subjects: Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Stability (probability), general [pulsars], Pulsar, Millisecond pulsar, Observatory, pulsars: general, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, time, Physics, 010308 nuclear & particles physics, Gravitational wave, Spectral density, Astronomy and Astrophysics, Atomic clock, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics - Instrumentation and Methods for Astrophysics, Noise (radio), Astronomical and Space Sciences
Abstract: We have constructed a new timescale, TT(IPTA16), based on observations of radio pulsars presented in the first data release from the International Pulsar Timing Array (IPTA). We used two analysis techniques with independent estimates of the noise models for the pulsar observations and different algorithms for obtaining the pulsar timescale. The two analyses agree within the estimated uncertainties and both agree with TT(BIPM17), a post-corrected timescale produced by the Bureau International des Poids et Mesures (BIPM). We show that both methods could detect significant errors in TT(BIPM17) if they were present. We estimate the stability of the atomic clocks from which TT(BIPM17) is derived using observations of four rubidium fountain clocks at the US Naval Observatory. Comparing the power spectrum of TT(IPTA16) with that of these fountain clocks suggests that pulsar-based timescales are unlikely to contribute to the stability of the best timescales over the next decade, but they will remain a valuable independent check on atomic timescales. We also find that the stability of the pulsar-based timescale is likely to be limited by our knowledge of solar-system dynamics, and that errors in TT(BIPM17) will not be a limiting factor for the primary goal of the IPTA, which is to search for the signatures of nano-Hertz gravitational waves., Comment: accepted by MNRAS
Published: 2020
Full Text: View/download PDF

5. Dispersion measure variability for 36 millisecond pulsars at 150 MHz with LOFAR

Author: Rene P. Breton, C. Vocks, A. V. Bilous, Stefan Oslowski, J. Y. Donner, J. Künsemöller, Michael Kramer, A.-S. Bak Nielsen, Evan Keane, James M. Anderson, V. I. Kondratiev, M. Serylak, Caterina Tiburzi, B. Ciardi, O. Wucknitz, Marcus Brüggen, Charlotte Sobey, J. van Leeuwen, J. W. McKee, Joris P. W. Verbiest, Matthias Hoeft, J.-M. Grießmeier, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), CNRS-INSU, and European Project: 617199,EC:FP7:ERC,ERC-2013-CoG,ALERT(2014)
Subjects: ISM: structure, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Telescope, Pulsar, Millisecond pulsar, law, pulsars: general, 0103 physical sciences, Dispersion (optics), 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [PHYS]Physics [physics], 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, LOFAR, Astrophysics - Astrophysics of Galaxies, gravitational waves, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), ddc:520, Radio frequency, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Noise (radio)
Abstract: Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments, including pulsar timing arrays that aim to detect nanohertz gravitational waves. We aim to quantify the time-variable dispersion with much improved precision and characterise the spectrum of these variations. We use the pulsar timing technique to obtain highly precise dispersion measure (DM) time series. Our dataset consists of observations of 36 millisecond pulsars, which were observed for up to 7.1 years with the LOFAR telescope at a centre frequency of ~150 MHz. Seventeen of these sources were observed with a weekly cadence, while the rest were observed at monthly cadence. We achieve a median DM precision of the order of 10^-5 cm^-3 pc for a significant fraction of our sources. We detect significant variations of the DM in all pulsars with a median DM uncertainty of less than 2x10^-4 cm^-3 pc. The noise contribution to pulsar timing experiments at higher frequencies is calculated to be at a level of 0.1-10 us at 1.4 GHz over a timespan of a few years, which is in many cases larger than the typical timing precision of 1 us or better that PTAs aim for. We found no evidence for a dependence of DM on radio frequency for any of the sources in our sample. The DM time series we obtained using LOFAR could in principle be used to correct higher-frequency data for the variations of the dispersive delay. However, there is currently the practical restriction that pulsars tend to provide either highly precise times of arrival (ToAs) at 1.4 GHz or a high DM precision at low frequencies, but not both, due to spectral properties. Combining the higher-frequency ToAs with those from LOFAR to measure the infinite-frequency ToA and DM would improve the result., Comment: 16 pages, 8 figures, 2 tables
Published: 2020
Full Text: View/download PDF

6. Measuring Interstellar Delays of PSR J0613-0200 over 7 years, using the Large European Array for Pulsars

Author: M. Gaikwad, Kejia Lee, S. Sanidas, C. G. Bassa, Siyuan Chen, John Antoniadis, Mitchell B. Mickaliger, Gemma H. Janssen, Weiwei Zhu, Benjamin Stappers, Long Wang, H. Hu, G. Mall, Delphine Perrodin, Olaf Wucknitz, Michael Kramer, Caterina Tiburzi, Ramesh Karuppusamy, Ismaël Cognard, R. A. Main, J. W. McKee, Kang Liu, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), ITA, GBR, FRA, DEU, CAN, GRC, NLD, and CHN
Subjects: Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Telescope, pulsars: individual: PSR J0613−0200, Pulsar, Millisecond pulsar, law, pulsars: general, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Scintillation, 010308 nuclear & particles physics, Scattering, Gravitational wave, Spectral density, Astronomy and Astrophysics, Pulse (physics), Space and Planetary Science, [SDU]Sciences of the Universe [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract: Using data from the Large European Array for Pulsars (LEAP), and the Effelsberg telescope, we study the scintillation parameters of the millisecond pulsar J0613-0200 over a 7 year timespan. The "secondary spectrum" -- the 2D power spectrum of scintillation -- presents the scattered power as a function of time delay, and contains the relative velocities of the pulsar, observer, and scattering material. We detect a persistent parabolic scintillation arc, suggesting scattering is dominated by a thin, anisotropic region. The scattering is poorly described by a simple exponential tail, with excess power at high delays; we measure significant, detectable scattered power at times out to $\sim 5 \mu s$, and measure the bulk scattering delay to be between 50 to 200\,ns with particularly strong scattering throughout 2013. These delays are too small to detect a change of the pulse profile shape, yet they would change the times-of-arrival as measured through pulsar timing. The arc curvature varies annually, and is well fit by a one-dimensional scattering screen $\sim 40\%$ of the way towards the pulsar, with a changing orientation during the increased scattering in 2013. Effects of uncorrected scattering will introduce time delays correlated over time in individual pulsars, and may need to be considered in gravitational wave analyses. Pulsar timing programs would benefit from simultaneously recording in a way that scintillation can be resolved, in order to monitor the variable time delays caused by multipath propagation., Comment: 12 pages, 10 figures. Published in MNRAS
Published: 2020
Full Text: View/download PDF

7. The International Pulsar Timing Array: Second data release

Author: Sarah Burke-Spolaor, Robert D. Ferdman, Stephen Taylor, Lei Zhang, Janna Goldstein, Caterina Tiburzi, Alberto Sesana, Ingrid H. Stairs, Elizabeth C. Ferrara, N. D. R. Bhat, Benetge Perera, Aditya Parthasarathy, Michael Kramer, H. Hu, Richard N. Manchester, Joseph Simon, L. Lentati, Matthew Kerr, Shi Dai, R. N. Caballero, Megan E. DeCesar, Paul Demorest, A. Possenti, Xing-Jiang Zhu, Kathryn Crowter, Weiwei Zhu, C. G. Bassa, Emmanuel Fonseca, Kejia Lee, Scott M. Ransom, Michael Keith, Stefan Oslowski, Chiara M. F. Mingarelli, D. J. Champion, Ramesh Karuppusamy, David J. Nice, Andrew Lyne, Timothy T. Pennucci, Timothy Dolch, J. K. Swiggum, Benjamin Stappers, K. Islo, Lucas Guillemot, Michele Vallisneri, J. B. Wang, X. Siemens, Gregory Desvignes, Gilles Theureau, James M. Cordes, Ismaël Cognard, Renée Spiewak, Siyuan Chen, Jing Luo, S. A. Sanidas, P. T. Baker, A. Brazier, Songbo Zhang, Alberto Vecchio, George Hobbs, Delphine Perrodin, Michael T. Lam, Jeffrey S. Hazboun, M. Burgay, Daniel J. Reardon, Zaven Arzoumanian, G. Shaifullah, J. W. McKee, Maura McLaughlin, Christopher J. Russell, Sourav Chatterjee, Kang Liu, Matthew Bailes, Gemma H. Janssen, Ryan Shannon, E. Graikou, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Perera, B, Decesar, M, Demorest, P, Kerr, M, Lentati, L, Nice, D, Osłowski, S, Ransom, S, Keith, M, Arzoumanian, Z, Bailes, M, Baker, P, Bassa, C, Bhat, N, Brazier, A, Burgay, M, Burke-Spolaor, S, Caballero, R, Champion, D, Chatterjee, S, Chen, S, Cognard, I, Cordes, J, Crowter, K, Dai, S, Desvignes, G, Dolch, T, Ferdman, R, Ferrara, E, Fonseca, E, Goldstein, J, Graikou, E, Guillemot, L, Hazboun, J, Hobbs, G, Hu, H, Islo, K, Janssen, G, Karuppusamy, R, Kramer, M, Lam, M, Lee, K, Liu, K, Luo, J, Lyne, A, Manchester, R, Mckee, J, Mclaughlin, M, Mingarelli, C, Parthasarathy, A, Pennucci, T, Perrodin, D, Possenti, A, Reardon, D, Russell, C, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Siemens, X, Simon, J, Spiewak, R, Stairs, I, Stappers, B, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Vallisneri, M, Vecchio, A, Wang, J, Zhang, S, Zhang, L, Zhu, W, Zhu, X, Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Ephemeris, 01 natural sciences, Pulsar timing array, stars: neutron, neutron [stars], Pulsar, Millisecond pulsar, Observatory, pulsars: general, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, methods: data analysis, European Pulsar Timing Array, gravitational waves, Space and Planetary Science, [SDU]Sciences of the Universe [physics], pulsars, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Noise (radio), Methods: data analysi
Abstract: In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. We analyse and where possible combine high-precision timing data for 65 millisecond pulsars which are regularly observed by these groups. A basic noise analysis, including the processes which are both correlated and uncorrelated in time, provides noise models and timing ephemerides for the pulsars. We find that the timing precisions of pulsars are generally improved compared to the previous data release, mainly due to the addition of new data in the combination. The main purpose of this work is to create the most up-to-date IPTA data release. These data are publicly available for searches for low-frequency gravitational waves and other pulsar science., Comment: Submitted to MNRAS and in review, 23 pages, 5 figures
Published: 2019
Full Text: View/download PDF

8. High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array

Author: P. Lazarus, R. van Haasteren, Christine Jordan, Pablo Rosado, Jason W. T. Hessels, S. Babak, Alberto Sesana, Joris P. W. Verbiest, Chiara M. F. Mingarelli, Benjamin Stappers, A. Jessner, D. J. Champion, J. W. McKee, J. R. Gair, Lucas Guillemot, Delphine Perrodin, Antoine Petiteau, P. Brem, Michael Kramer, Ramesh Karuppusamy, Andrew Lyne, Ismaël Cognard, Gregory Desvignes, Gilles Theureau, Kejia Lee, G. Shaifullah, E. Graikou, M. Burgay, Stefan Oslowski, M. B. Purver, Caterina Tiburzi, R. Smits, K. Lazaridis, Stephen Taylor, R. N. Caballero, Kang Liu, C. G. Bassa, A. Lassus, Gemma H. Janssen, Alberto Vecchio, S. Sanidas, L. Lentati, A. Possenti, Desvignes, G, Caballero, R, Lentati, L, Verbiest, J, Champion, D, Stappers, B, Janssen, G, Lazarus, P, Osłowski, S, Babak, S, Bassa, C, Brem, P, Burgay, M, Cognard, I, Gair, J, Graikou, E, Guillemot, L, Hessels, J, Jessner, A, Jordan, C, Karuppusamy, R, Kramer, M, Lassus, A, Lazaridis, K, Lee, K, Liu, K, Lyne, A, Mckee, J, Mingarelli, C, Perrodin, D, Petiteau, A, Possenti, A, Purver, M, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Smits, R, Taylor, S, Theureau, G, Tiburzi, C, van Haasteren, R, Vecchio, A, Max-Planck-Institut für Radioastronomie (MPIFR), Cavendish Laboratory, University of Cambridge [UK] (CAM), Universität Bielefeld, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy ( ASTRON ), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of Amsterdam [Amsterdam] (UvA), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Theoretical Astrophysics [Pasadena] (TAPIR), California Institute of Technology (CALTECH), Birmingham City University (BCU), National Natural Science Foundation of China (Grant No.11373011)., European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: astro-ph.SR, FOS: Physical sciences, Proper motion, Astrophysics, Magnetar, 01 natural sciences, Radio spectrum, Radio telescope, Pulsar timing array, proper motions, Pulsar, Millisecond pulsar, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Stars: Distance, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Pulsars: General, Astronomy, Astronomy and Astrophysics, pulsars:general, European Pulsar Timing Array, Neutron star, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, stars: distances, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, stars:distances, astro-ph.IM
Abstract: We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 years. It forms the basis for the stochastic gravitational-wave background, anisotropic background, and continuous-wave limits recently presented by the EPTA elsewhere. The Bayesian timing analysis performed with TempoNest yields the detection of several new parameters: seven parallaxes, nine proper motions and, in the case of six binary pulsars, an apparent change of the semi-major axis. We find the NE2001 Galactic electron density model to be a better match to our parallax distances (after correction from the Lutz-Kelker bias) than the M2 and M3 models by Schnitzeler (2012). However, we measure an average uncertainty of 80\% (fractional) for NE2001, three times larger than what is typically assumed in the literature. We revisit the transverse velocity distribution for a set of 19 isolated and 57 binary MSPs and find no statistical difference between these two populations. We detect Shapiro delay in the timing residuals of PSRs J1600$-$3053 and J1918$-$0642, implying pulsar and companion masses $m_p=1.22_{-0.35}^{+0.5} \text{M}_{\odot}$, $m_c = 0.21_{-0.04}^{+0.06} \text{M}_{\odot }$ and $m_p=1.25_{-0.4}^{+0.6} \text{M}_{\odot}$, $m_c = 0.23_{-0.05}^{+0.07} \text{M}_{\odot }$, respectively. Finally, we use the measurement of the orbital period derivative to set a stringent constraint on the distance to PSRs J1012$+$5307 and J1909$-$3744, and set limits on the longitude of ascending node through the search of the annual-orbital parallax for PSRs J1600$-$3053 and J1909$-$3744., Comment: 42 pages, 11 figures. Accepted for publication in MNRAS
Published: 2016
Full Text: View/download PDF

9. From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release

Author: R. van Haasteren, Scott M. Ransom, S. Babak, Antoine Petiteau, Paul Demorest, L. Toomey, Gemma H. Janssen, Alberto Sesana, Marjorie Gonzalez, Sourav Chatterjee, A. Lassus, Ryan Shannon, Justin A. Ellis, Glenn Jones, E. Graikou, J. W. McKee, Kang Liu, Kejia Lee, Matthew Kerr, Sarah Burke-Spolaor, William A. Coles, Maura McLaughlin, G. Shaifullah, Stephen Taylor, Weiwei Zhu, P. Lazarus, S. A. Sanidas, D. J. Champion, Delphine Perrodin, R. N. Caballero, Kevin Stovall, Joris P. W. Verbiest, Benetge Perera, Richard N. Manchester, C. G. Bassa, Emmanuel Fonseca, Jonathan R. Gair, George Hobbs, D. R. Madison, R. Smits, Alberto Vecchio, Daniel R. Stinebring, Michael T. Lam, Daniel J. Reardon, X. P. You, Zaven Arzoumanian, Paul D. Lasky, Yue-Fei Wang, Lucas Guillemot, R. S. Lynch, Pablo Rosado, Lina Levin, Xing-Jiang Zhu, Chiara M. F. Mingarelli, L. Lentati, Benjamin Stappers, A. Possenti, T. J. W. Lazio, Robert D. Ferdman, Stefan Oslowski, J. K. Swiggum, X. Siemens, Gregory Desvignes, Gilles Theureau, Ramesh Karuppusamy, Ismaël Cognard, M. Burgay, Timothy T. Pennucci, Michele Vallisneri, J. B. Wang, James M. Cordes, Sean T. McWilliams, David J. Nice, P. Brem, W. van Straten, Caterina Tiburzi, N. D. R. Bhat, Shi Dai, Jason W. T. Hessels, Ingrid H. Stairs, Timothy Dolch, Michael Kramer, Michael Keith, Lentati, L, Shannon, R, Coles, W, Verbiest, J, van Haasteren, R, Ellis, J, Caballero, R, Manchester, R, Arzoumanian, Z, Babak, S, Bassa, C, Bhat, N, Brem, P, Burgay, M, Burke-Spolaor, S, Champion, D, Chatterjee, S, Cognard, I, Cordes, J, Dai, S, Demorest, P, Desvignes, G, Dolch, T, Ferdman, R, Fonseca, E, Gair, J, Gonzalez, M, Graikou, E, Guillemot, L, Hessels, J, Hobbs, G, Janssen, G, Jones, G, Karuppusamy, R, Keith, M, Kerr, M, Kramer, M, Lam, M, Lasky, P, Lassus, A, Lazarus, P, Lazio, T, Lee, K, Levin, L, Liu, K, Lynch, R, Madison, D, Mckee, J, Mclaughlin, M, Mcwilliams, S, Mingarelli, C, Nice, D, Osłowski, S, Pennucci, T, Perera, B, Perrodin, D, Petiteau, A, Possenti, A, Ransom, S, Reardon, D, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Siemens, X, Smits, R, Stairs, I, Stappers, B, Stinebring, D, Stovall, K, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Toomey, L, Vallisneri, M, van Straten, W, Vecchio, A, Wang, J, Wang, Y, You, X, Zhu, W, Zhu, X, High Energy Astrophys. & Astropart. Phys (API, FNWI), Cavendish Laboratory, University of Cambridge [UK] (CAM), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), University of California, University of California (UC), Max-Planck-Institut für Radioastronomie (MPIFR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Netherlands Institute for Radio Astronomy (ASTRON), Curtin University [Perth], Planning and Transport Research Centre (PATREC), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), National Radio Astronomy Observatory (NRAO), Center for Radiophysics and Space Research [Ithaca] (CRSR), Cornell University [New York], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Department of Astronomy [Ithaca], Department of Physics, Hillsdale College, Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of British Columbia (UBC), Vancouver Coastal Health, Department of Nuclear Medicine, Netherlands Institute for Radio Astronomy ( ASTRON ), ARC Centre of Excellence for Coral Reef Studies (CoralCoE), James Cook University (JCU), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Vrije Universiteit Medical Centre (VUMC), Vrije Universiteit Amsterdam [Amsterdam] (VU), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], National Radio Astronomy Observatory [Green Bank] (NRAO), Jodrell Bank Centre for Astrophysics (JBCA), Department of Physics, West Virginia University, West Virginia University, Theoretical Astrophysics [Pasadena] (TAPIR), California Institute of Technology (CALTECH), Physics Department, Lafayette College, Lafayette College [Easton], Department of Astronomy [Charlottesville], University of Virginia, APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), University of Wisconsin - Milwaukee, Department of Physics and Astronomy, University of British Columbia, Department of Physics and Astronomy [Oberlin], Oberlin College, Institute of Meteoritics [Albuquerque] (IOM), The University of New Mexico [Albuquerque], Department of Physics and Astronomy, West Virginia University, West Virginia University [Morgantown], Birmingham City University (BCU), Xinjiang Astronomical Observatory, Chinese Academy of Sciences [Beijing] (CAS), Huazhong University of Science and Technology [Wuhan] (HUST), School of Physical Science and Technology, Southwest University [Chongqing], Australian Research Council Discovery Project DP140102578NASA through Einstein Fellowship grant PF3-140116West Light Foundation of CAS XBBS201322 and NSFC project no.11403086National Science Fundation of China (NSFC) award number 11503007NNSF of China (U1231120) and FRFCU (XDJK2015B012), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), Cornell University, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), California Institute of Technology (CALTECH)-NASA, Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), University of Virginia [Charlottesville], 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)-Observatoire de Paris, and 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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, data analysis, pulsars: general [methods], FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Methods: Data analysi, Astrophysics, Astronomy & Astrophysics, general [pulsars], 01 natural sciences, General Relativity and Quantum Cosmology, pulsars:individual, Binary pulsar, Pulsar, 0103 physical sciences, data analysis [methods], Coherence (signal processing), Sensitivity (control systems), Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Stochastic process, Noise (signal processing), Model selection, Pulsars: General, Astronomy and Astrophysics, methods: data analysis, LIGO, Computational physics, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astronomical and Space Sciences
Abstract: We analyse the stochastic properties of the 49 pulsars that comprise the first International Pulsar Timing Array (IPTA) data release. We use Bayesian methodology, performing model selection to determine the optimal description of the stochastic signals present in each pulsar. In addition to spin-noise and dispersion-measure (DM) variations, these models can include timing noise unique to a single observing system, or frequency band. We show the improved radio-frequency coverage and presence of overlapping data from different observing systems in the IPTA data set enables us to separate both system and band-dependent effects with much greater efficacy than in the individual PTA data sets. For example, we show that PSR J1643$-$1224 has, in addition to DM variations, significant band-dependent noise that is coherent between PTAs which we interpret as coming from time-variable scattering or refraction in the ionised interstellar medium. Failing to model these different contributions appropriately can dramatically alter the astrophysical interpretation of the stochastic signals observed in the residuals. In some cases, the spectral exponent of the spin noise signal can vary from 1.6 to 4 depending upon the model, which has direct implications for the long-term sensitivity of the pulsar to a stochastic gravitational-wave (GW) background. By using a more appropriate model, however, we can greatly improve a pulsar's sensitivity to GWs. For example, including system and band-dependent signals in the PSR J0437$-$4715 data set improves the upper limit on a fiducial GW background by $\sim 60\%$ compared to a model that includes DM variations and spin-noise only., Comment: 29 pages. 16 figures. Accepted for publication in MNRAS
Published: 2016
Full Text: View/download PDF

10. The International Pulsar Timing Array: First data release

Author: Lucas Guillemot, Sourav Chatterjee, N. Garver-Daniels, D. R. Madison, Scott M. Ransom, J. K. Swiggum, Daniel R. Stinebring, Delphine Perrodin, Ingrid H. Stairs, Alberto Vecchio, Timothy Dolch, X. Siemens, Gregory Desvignes, Antoine Petiteau, Gilles Theureau, W. van Straten, J. B. Wang, X. P. You, Jason W. T. Hessels, Renée Spiewak, R. N. Caballero, Alberto Sesana, Stefan Oslowski, R. S. Lynch, Xing-Jiang Zhu, C. G. Bassa, Emmanuel Fonseca, Daniel J. Reardon, Yue-Fei Wang, Chiara M. F. Mingarelli, Benjamin Stappers, Kejia Lee, Stanislav Babak, Benetge Perera, Pablo Rosado, Zaven Arzoumanian, Richard N. Manchester, Paul Demorest, A. Brazier, Jonathan R. Gair, R. van Haasteren, Nipuni Palliyaguru, Lina Levin, R. Smits, Joseph Simon, P. Brem, Michele Vallisneri, Michael Kramer, James M. Cordes, Andrew Lyne, L. Lentati, Weiwei Zhu, Matthew Kerr, Peter A. Gentile, Michael Keith, A. Possenti, D. J. Champion, Caterina Tiburzi, T. J. W. Lazio, N. D. R. Bhat, A. Lassus, Stephen Taylor, Linqing Wen, Ryan Shannon, Glenn Jones, Shi Dai, E. Graikou, Gemma H. Janssen, S. J. Chamberlin, Kevin Stovall, Kang Liu, P. Lazarus, Ramesh Karuppusamy, S. A. Sanidas, Ismaël Cognard, George Hobbs, Robert D. Ferdman, Timothy T. Pennucci, M. Burgay, Sean T. McWilliams, David J. Nice, B. Christy, G. Shaifullah, L. Toomey, Justin A. Ellis, J. W. McKee, Maura McLaughlin, Paul D. Lasky, Michael T. Lam, Sarah Burke-Spolaor, Joris P. W. Verbiest, Marjorie Gonzalez, High Energy Astrophys. & Astropart. Phys (API, FNWI), Verbiest, J, Lentati, L, Hobbs, G, van Haasteren, R, Demorest, P, Janssen, G, Wang, J, Desvignes, G, Caballero, R, Keith, M, Champion, D, Arzoumanian, Z, Babak, S, Bassa, C, Bhat, N, Brazier, A, Brem, P, Burgay, M, Burke-Spolaor, S, Chamberlin, S, Chatterjee, S, Christy, B, Cognard, I, Cordes, J, Dai, S, Dolch, T, Ellis, J, Ferdman, R, Fonseca, E, Gair, J, Garver-Daniels, N, Gentile, P, Gonzalez, M, Graikou, E, Guillemot, L, Hessels, J, Jones, G, Karuppusamy, R, Kerr, M, Kramer, M, Lam, M, Lasky, P, Lassus, A, Lazarus, P, Lazio, T, Lee, K, Levin, L, Liu, K, Lynch, R, Lyne, A, Mckee, J, Mclaughlin, M, Mcwilliams, S, Madison, D, Manchester, R, Mingarelli, C, Nice, D, Osłowski, S, Palliyaguru, N, Pennucci, T, Perera, B, Perrodin, D, Possenti, A, Petiteau, A, Ransom, S, Reardon, D, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Siemens, X, Simon, J, Smits, R, Spiewak, R, Stairs, I, Stappers, B, Stinebring, D, Stovall, K, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Toomey, L, Vallisneri, M, van Straten, W, Vecchio, A, Wang, Y, Wen, L, You, X, Zhu, W, Zhu, X, Max-Planck-Institut für Radioastronomie (MPIFR), Cavendish Laboratory, University of Cambridge [UK] (CAM), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Netherlands Institute for Radio Astronomy (ASTRON), Xinjiang Astronomical Observatory, Chinese Academy of Sciences [Beijing] (CAS), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Curtin University [Perth], Planning and Transport Research Centre (PATREC), Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University [New York], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Pennsylvania State University (Penn State), Penn State System, Center for Radiophysics and Space Research [Ithaca] (CRSR), University of Maryland [College Park], University of Maryland System, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Department of Astronomy [Ithaca], Department of Physics, Hillsdale College, University of British Columbia (UBC), University of Edinburgh, Department of Physics and Astronomy, West Virginia University, West Virginia University [Morgantown], Vancouver Coastal Health, Department of Nuclear Medicine, Department of Physics, Columbia University, Columbia University [New York], Monash Centre for Astrophysics (MoCA), Monash University [Clayton], Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], National Radio Astronomy Observatory [Green Bank] (NRAO), Theoretical Astrophysics [Pasadena] (TAPIR), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Physics Department, Lafayette College, Lafayette College [Easton], Physics Department, Texas Tech University, Texas Tech University [Lubbock] (TTU), Department of Astronomy [Charlottesville], University of Virginia [Charlottesville], APC - Gravitation (APC-Gravitation), 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), University of Wisconsin - Milwaukee, Center for Gravitation, Cosmology and Astrophysics, Netherlands Institute for Radio Astronomy ( ASTRON ), Department of Physics and Astronomy, University of British Columbia, Department of Physics and Astronomy [Oberlin], Oberlin College, Department of Physics and Astronomy [Albuquerque], The University of New Mexico [Albuquerque], Birmingham City University (BCU), School of Physics [HUST], Huazhong University of Science and Technology [Wuhan] (HUST), School of Physics (University of Western Australia), Université, School of Physical Science and Technology, Southwest University [Chongqing], European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Max-Planck-Institut für Radioastronomie, Cavendish Laboratory - University of Cambridge, University of Cambridge [UK] ( CAM ), CSIRO Astronomy and Space Science, PO BOX 76, NSW 1710, Australia, Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), National Radio Astronomy Observatory [Socorro] ( NRAO ), National Radio Astronomy Observatory ( NRAO ), Netherlands Institute for Radio Astronomy, Chinese Academy of Sciences [Beijing] ( CAS ), NASA Goddard Space Flight Center ( GSFC ), Albert Einstein Institute, Max-Planck-Institut für Gravitationsphysik, Curtin University, Perth, Australia, Cornell Center for Astrophysics and Planetary Science ( CCAPS ), Cornell University, MPI for Gravitational Physics (Albert Einstein Institute), INAF-Osservatorio di Cagliari, PennState University [Pennsylvania] ( PSU ), Center for Radiophysics and Space Research [Ithaca] ( CRSR ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), University of British Columbia ( UBC ), University of Edimburgh, Kavli Institute for Astronomy and Astrophysics, National Radio Astronomy Observatory [Green Bank] ( NRAO ), Commonwealth Scientific and Industrial Research Organisation [Canberra] ( CSIRO ), TAPIR (Theoretical Astrophysics), California Institute of Technology, Texas Tech University [Lubbock] ( TTU ), Osservatorio Astronomico di Cagliari, Ist Nazl Astrofis, Osservatorio Astronomico di Cagliari, APC - Gravitation ( APC-Gravitation ), 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 ) -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 ) -Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Max-Planck-Institut-Max-Planck-Institut, Centre for Astrophysics and Supercomputing [Swinburne] ( CAS ), Anton Pannekoek Institute for Astronomy, University of Amsterdam, Max Planck Institut für Gravitationsphysik, Albert Einstein Institut, Physics and Astronomy Department [Oberlin], Center for Gravitational Wave Astronomy, The University of Texas at Brownsville and Texas Southmost College, Birmingham City University ( BCU ), School of Physics, Huazhong University of Science and Technology, Huazhong University of Science and Technology, School of Physics ( University of Western Australia ), European Project : 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET ( 2014 ), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), University of Virginia, 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)-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)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), 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)-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, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI)
Subjects: data analysis, data analysis, pulsars: general [methods], FOS: Physical sciences, Methods: Data analysi, general [pulsars], 01 natural sciences, 7. Clean energy, Set (abstract data type), Pulsar timing array, Pulsar, 0103 physical sciences, data analysis [methods], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, instrumentation, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Pulsars: General, Astronomy, Astronomy and Astrophysics, methods: data analysis, Data set, European Pulsar Timing Array, Neutron star, gravitational waves, Space and Planetary Science, pulsars, Measurement uncertainty, Astrophysics - Instrumentation and Methods for Astrophysics, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Algorithm, astro-ph.IM
Abstract: The highly stable spin of neutron stars can be exploited for a variety of (astro-)physical investigations. In particular arrays of pulsars with rotational periods of the order of milliseconds can be used to detect correlated signals such as those caused by gravitational waves. Three such "Pulsar Timing Arrays" (PTAs) have been set up around the world over the past decades and collectively form the "International" PTA (IPTA). In this paper, we describe the first joint analysis of the data from the three regional PTAs, i.e. of the first IPTA data set. We describe the available PTA data, the approach presently followed for its combination and suggest improvements for future PTA research. Particular attention is paid to subtle details (such as underestimation of measurement uncertainty and long-period noise) that have often been ignored but which become important in this unprecedentedly large and inhomogeneous data set. We identify and describe in detail several factors that complicate IPTA research and provide recommendations for future pulsar timing efforts. The first IPTA data release presented here (and available online) is used to demonstrate the IPTA's potential of improving upon gravitational-wave limits placed by individual PTAs by a factor of ~2 and provides a 2-sigma limit on the dimensionless amplitude of a stochastic GWB of 1.7x10^{-15} at a frequency of 1 yr^{-1}. This is 1.7 times less constraining than the limit placed by (Shannon et al. 2015), due mostly to the more recent, high-quality data they used., 25 pages, 6 tables, 5 figures. Accepted for publication in MNRAS
Published: 2016
Full Text: View/download PDF

11. A double-blind, placebo-controlled interaction study between oxcarbazepine and carbamazepine, sodium valproate and phenytoin in epileptic patients

Author: R. A. Gillham, M. J. Brodie, G. Forrest, D. Connelly, S. M. Walker, P. J. W. Mckee, and Jackie Blacklaw
Subjects: Adult, Male, Phenytoin, medicine.medical_treatment, Oxcarbazepine, Placebo, Double-Blind Method, Pharmacokinetics, medicine, Humans, Drug Interactions, Pharmacology (medical), Active metabolite, Pharmacology, Epilepsy, business.industry, Valproic Acid, Carbamazepine, Middle Aged, Drug interaction, Anticonvulsant, Anesthesia, Anticonvulsants, Female, business, Research Article, Half-Life, medicine.drug
Abstract: 1. The effect of carbamazepine (CBZ), sodium valproate (VPA) and phenytoin (PHT) on the pharmacokinetics of oxcarbazepine (OXC) was explored in three groups of 12 epileptic patients taking one of these drug as monotherapy. 2. Each patient took a single 600 mg dose of OXC followed 7 days later by 3 weeks' treatment with OXC 300 mg thrice daily and matched placebo in random order. 3. Seven untreated patients, acting as controls, were prescribed the single OXC dose and 3 weeks' active treatment only. 4. In those patients completing the study, the area under the concentration-time curve (AUC) at steady-state for hydroxycarbazepine (OHCZ), the active metabolite of OXC, was significantly lower in the CBZ-treated group than in controls (P < 0.05). 5. No other differences in AUCs or elimination half-lives for OHCZ were found between treated and untreated patients following single or multiple OXC dosing. 6. Median AUCs of CBZ, VPA and PHT during a dosage interval did not differ significantly after treatment with OXC and placebo. 7. Ten patients completing the study complained of side-effects during treatment with OXC compared with one taking placebo (P < 0.01). 8. There were no important changes in cognitive function testing during administration of OXC compared with placebo. 9. Standard doses of OXC can be given as add-on therapy in epileptic patients receiving CBZ, VPA or PHT without producing a clinically relevant pharmacokinetic interaction.
Published: 1994
Full Text: View/download PDF

12. Effect of vigabatrin on sedation and cognitive function in patients with refractory epilepsy

Author: J. Blacklaw, P. J. W. Mckee, MartinJ. Brodie, and R A Gillham
Subjects: Adult, Male, Time Factors, Adolescent, genetic structures, Sedation, medicine.medical_treatment, Neuropsychological Tests, Placebo, Vigabatrin, Epilepsy, Cognition, Double-Blind Method, Memory, medicine, Humans, Aminocaproates, Psychomotor learning, Analysis of Variance, Neuropsychology, Middle Aged, medicine.disease, Crossover study, Psychiatry and Mental health, Anticonvulsant, Anesthesia, Anticonvulsants, Female, Surgery, Neurology (clinical), medicine.symptom, Sleep, Psychology, Follow-Up Studies, Research Article, medicine.drug
Abstract: Twenty-four patients with refractory epilepsy on one or more antiepileptic drugs were given additional vigabatrin (1 g twice daily for six weeks, followed by 1.5 g twice daily for a further six weeks) and matched placebo in a double blind, randomised, crossover study. A battery of neuropsychological tests was administered at baseline and at weeks two, six and 12 of both treatment periods. No significant differences were found between vigabatrin and placebo at any time point for any of the objective tests of cognitive function. Patients, however, reported a greater degree of sedation after two and six weeks on vigabatrin than during the equivalent placebo phase (p < 0.01), although no such difference was apparent at 12 weeks. Follow up over a mean of 14.75 months in 12 responders, who continued on vigabatrin, revealed a significant improvement (all p < 0.01) on each of three composite scales (three psychomotor tests, four memory tests, three self rating scales) compared with their scores during the double blind trial. Vigabatrin did not cause cognitive impairment either acutely or in the long term. Phased introduction, however, seems a prudent policy to allow tolerance to early subjective sedation.
Published: 1993
Full Text: View/download PDF

13. Double dummy comparison between once and twice daily dosing with modified-release carbamazepine in epileptic patients

Author: P. J. W. Mckee, R. A. Gillham, J. Blacklaw, M. J. Brodie, and A. Carswell
Subjects: Adult, Male, Cmax, Placebo, Drug Administration Schedule, Cmin, Double-Blind Method, medicine, Humans, Pharmacology (medical), Dosing, Morning, Pharmacology, Cross-Over Studies, Epilepsy, business.industry, Carbamazepine, Middle Aged, Crossover study, Anesthesia, Anticonvulsants, Female, business, Research Article, medicine.drug, Blood sampling
Abstract: 1. Fourteen patients with refractory epilepsy on a twice daily regimen of modified-release carbamazepine (CBZ-MR. Tegretol Retard. Ciba Pharmaceuticals) completed a balanced, double-blind, double dummy, random order, crossover comparison of 8 weeks treatment with once (o.d.) and twice daily (b.d.) dosing. In order to obtain a profile of serum CBZ concentrations over 24 h on once daily dosing, patients were randomised to taking it in the morning (o.d. a.m.) or evening (o.d. p.m.) for 4 weeks. Each treatment was taken with a placebo of the other and total tablet numbers were matched. Blood sampling was undertaken 0, 2, 4, 6, 8, 10, 12 and 24 h after the morning tablets at the end of each 4 week treatment period. 2. Overall, trough serum drug concentrations (Cmin) were lower with once daily dosing (Cmin: b.d. 7.5 mg l-1, o.d. 6.5 mg l-1, P < 0.05, 95% CI of the difference -1.3 to -0.1), but no significant differences were found in average (Cav) or peak (Cmax) concentrations, AUC values or fluctuations in CBZ concentrations. 3. Pharmacokinetic parameters for CBZ 10.11 epoxide, the active metabolite of CBZ did not differ significantly between the dosage schedules. 4. Seizure control was similar during once and twice daily dosing with CBZ-MR (median seizures/month (range): b.d. 1 (0-14.5), o.d. 0.5 (0-11), NS, 95% CI of the difference -1.8 to + 0.25). 5. There were no differences in psychomotor performance between the treatment periods. 6. More patients (n = 11) preferred treatment (P < 0.05) with once daily than twice daily dosing (n = 3) with CBZ-MR. 7. Once daily dosing with CBZ-MR should be possible in the majority of patients receiving the drug as monotherapy.
Published: 1993
Full Text: View/download PDF

14. Variability and clinical relevance of the interaction between sodium valproate and carbamazepine in epileptic patients

Author: Elaine Butler, J. Blacklaw, MartinJ. Brodie, P. J. W. Mckee, and R. A. Gillham
Subjects: Adult, Male, Adolescent, medicine.medical_treatment, Sodium, chemistry.chemical_element, Pharmacology, Epilepsy, Cognition, Pharmacokinetics, medicine, Humans, Drug Interactions, Active metabolite, Chemotherapy, business.industry, Valproic Acid, Carbamazepine, Middle Aged, Drug interaction, medicine.disease, Anticonvulsant, Neurology, chemistry, Female, lipids (amino acids, peptides, and proteins), Neurology (clinical), business, medicine.drug
Abstract: Twenty-four epileptic patients (16 females, 8 males; aged 13-62 years) were studied before and after the addition of sodium valproate (VPA) 500 mg twice daily for 5 days. All had been established previously on carbamazepine (CBZ) as monotherapy (300-1600 mg daily in divided doses). Sixteen of these patients undertook a battery of cognitive function tests before and after VPA introduction. VPA had no effect on total or free CBZ concentrations. However, median concentrations of the active metabolite, CBZ 10,11 epoxide (CBZ-E), were significantly increased (CBZ-E before VPA 1.3 mg/l, after VPA 2.1 mg/l, P less than 0.01). The median rise was 25%, although the extent of the interaction ranged from a 25% decrease to an increase of 123% in CBZ-E concentrations. This was related to the marked inter-individual variation in circulating VPA (mean 25-69 mg/l), as CBZ-E concentrations correlated significantly with total (r = 0.5, P less than 0.05, 95% CI 0 to +0.08) and free (r = 0.7, P less than 0.001, 95% CI +0.09 to +0.25) VPA levels in individual patients. Although uncontrolled, no deterioration in performance of any of the cognitive function tests was observed following the addition of VPA. This study does not support immediate clinical relevance for this drug interaction between VPA and CBZ.
Published: 1992
Full Text: View/download PDF

15. Rapid tolerance to acute psychomotor impairment with carbamazepine in epileptic patients

Author: M. J. Brodie, P. J. W. Mckee, and J. G. Larkin
Subjects: Adult, Male, medicine.medical_specialty, Adolescent, medicine.medical_treatment, Gastroenterology, Epilepsy, Oral administration, Internal medicine, Humans, Medicine, Pharmacology (medical), Active metabolite, Pharmacology, Psychomotor learning, Psychomotor function, business.industry, Drug Tolerance, Carbamazepine, Middle Aged, medicine.disease, Anticonvulsant, Anesthesia, Finger tapping, Female, business, Psychomotor Performance, Research Article, medicine.drug
Abstract: Thirteen patients with newly diagnosed epilepsy performed a battery of psychomotor function tests before and during the first 12 weeks of carbamazepine (CBZ) therapy. Movement time (P less than 0.025), total choice reaction time (P less than 0.025), finger tapping rate (P less than 0.005) and number cancellation (P less than 0.05) were all significantly impaired after 1 week's treatment, but had returned to baseline by 4 weeks. Mean (+/- s.d.) serum CBZ concentrations and those of its active metabolite CBZ 10,11 epoxide (CBZ-E) were comparable at 1 (CBZ: 8.5 +/- 2.1 mg l-1, CBZ-E: 1.1 +/- 0.68 mg l-1) and 4 weeks (CBZ: 8.1 +/- 4.4 mg l-1, CBZ-E: 0.93 +/- 0.27 mg l-1). These results suggest the rapid development of tolerance to the acute deleterious psychomotor effects of CBZ.
Published: 1992
Full Text: View/download PDF

16. Nimodipine in refractory epilepsy: A placebo-controlled, add-on study

Author: J. G. Larkin, P. J. W. Mckee, MartinJ. Brodie, G. G. Thompson, J. Blacklaw, and I.C Morgan
Subjects: Adult, Male, Adolescent, medicine.medical_treatment, Blood Pressure, Placebo, Epilepsy, Double-Blind Method, medicine, Humans, Pulse, Nimodipine, Polypharmacy, business.industry, Middle Aged, medicine.disease, Crossover study, Clinical trial, Anticonvulsant, Blood pressure, Neurology, Anesthesia, Female, Epilepsies, Partial, Neurology (clinical), business, medicine.drug
Abstract: Twenty-two patients (8 male, 14 female) with refractory epilepsy entered a balanced, double-blind, placebo-controlled crossover trial of nimodipine as adjunctive therapy. Treatment periods of 12 weeks (nimodipine 30 mg tds, 60 mg tds, 90 mg tds each for 4 weeks and matched placebo) were followed by wash-out intervals of 4 weeks. Five patients withdrew (2 side-effects, 1 intercurrent illness, 2 non-compliance). Median values (placebo vs. nimodipine) did not vary for total (17 vs. 18), partial (14 vs. 18) and generalised tonic-clonic seizures (2 vs. 5) or seizure days (13 vs. 13). Monthly analysis also failed to uncover any benefit for nimodipine. Side-effects were reported no more frequently with nimodipine than with placebo and pulse and blood pressure did not alter significantly. Antiepileptic drug levels were not affected by nimodipine treatment but circulating nimodipine concentrations were low. In this trial, nimodipine did not fulfil the promise of its success in animal models of epilepsy. Enzyme induction by concurrent antiepileptic therapy may provide an explanation.
Published: 1991
Full Text: View/download PDF

17. Physical and comparative mapping of distal mouse chromosome 16. 5 p5

Author: D E, Cabin, J W, McKee-Johnson, L E, Matesic, T, Wiltshire, E E, Rue, A E, Mjaatvedt, Y K, Huo, J R, Korenberg, and R H, Reeves
Subjects: Expressed Sequence Tags, Genetic Markers, Letter, Chromosomes, Human, Pair 21, Molecular Sequence Data, Trisomy, Blotting, Northern, Physical Chromosome Mapping, Chromosomes, Contig Mapping, Disease Models, Animal, Mice, Animals, Humans, RNA, Down Syndrome, Sequence Tagged Sites
Abstract: Distal mouse Chromosome 16 (Chr. 16) includes a region of conserved linkage with human Chromosome 21 (Chr. 21). Mouse models of Down syndrome based on trisomy of distal Chr. 16 have several phenotypes similar to those seen in human patients and have proven useful for correlating dosage imbalance of specific genes with specific developmental anomalies. The degree to which such findings can be related to Down syndrome depends on how well the conserved synteny is maintained. Twenty-four genes have been mapped in both species and there are no discordancies, but the region could carry hundreds of genes. Comparative sequence represents the ultimate comparative map and will aid in identification of genes and their regulatory sequences. A physical map of the distal 4.5 Mb of Chr. 16 has been assembled as an essential step toward a map of sequence-ready templates. The map consists of 51 YACs and 15 BACs and includes 18 transcripts, 9 of which are mapped for the first time in mouse, and 3 of which are, for the first time, described in either species. YAC fragmentation was used to precisely localize the 49 markers on the map. Comparison of this physical map with that of the corresponding region on Chr. 21 shows conservation not only of gene order but of size in the 3 Mb from Cbr1 to Ets2; distal to Ets2, the human map is expanded.
Published: 1998

18. Fragmentation and integrative modification of YACs

Author: J W, McKee-Johnson and R H, Reeves
Subjects: Genetic Markers, Recombination, Genetic, Blotting, Southern, Mutagenesis, Insertional, Transformation, Genetic, Genetic Vectors, DNA, Recombinant, Cloning, Molecular, Selection, Genetic, Chromosomes, Artificial, Yeast, Electrophoresis, Gel, Pulsed-Field, Gene Library, Repetitive Sequences, Nucleic Acid
Published: 1996

19. Adjuvant vigabatrin in refractory epilepsy: a ceiling to effective dosage in individual patients?

Author: P. J. W. Mckee, M. J. Brodie, Jackie Blacklaw, GG Thompson, R. A. Gillham, and E. Friel
Subjects: Adult, Male, Adolescent, Placebo, Vigabatrin, Drug Administration Schedule, law.invention, Placebos, Epilepsy, Pharmacotherapy, Randomized controlled trial, Double-Blind Method, law, Statistical significance, medicine, Adjuvant therapy, Humans, Aminocaproates, business.industry, Middle Aged, medicine.disease, Confidence interval, Treatment Outcome, Neurology, Anesthesia, Anticonvulsants, Drug Therapy, Combination, Female, Neurology (clinical), Epilepsies, Partial, business, medicine.drug
Abstract: A double-blind, randomized, cross-over study of additional vigabatrin (gamma-vinyl-GABA, VGB, 1.0 g twice daily for 6 weeks, followed by 1.5 g twice daily for 6 weeks) and matched placebo was undertaken in 24 patients with refractory epilepsy. Nineteen completed the trial satisfactorily. Fewer seizure days were reported during VGB treatment [placebo 41, VGB 23, p < 0.05, 95% confidence interval (CI) -1.5 to -14]. An overall reduction in median seizure numbers failed to reach statistical significance (n = 19; placebo 52, VGB 32, NS, 95% CI -18 to +24). Subgroup analysis, however, showed a significant reduction in partial seizures (n = 17) with 2 g VGB daily (placebo 22, VGB 13, p < 0.05, 95% CI -0.5 to -16.5), but not with higher dosage (placebo 28, VGB 22, NS, 95% CI -18 to +11). A deterioration in control of partial seizures as compared with the equivalent placebo phase was observed when patients were changed from 2 to 3 g/day VGB (2 g VGB 13, 3 g VGB 22, p = 0.05, 95% CI 0 to +20). Loss of efficacy was noted in 3 patients, and seizure control worsened slightly in 5 others. One previously resistant patient developed a therapeutic response, and 2 other patients reported an additional useful reduction in seizures. In the remaining 8 patients, seizure frequency did not change. VGB did not appear to benefit tonic-clonic seizures. Serum VGB concentrations were higher during treatment with 3 g (15.5 +/- 8.9 mg/L) daily than with 2 g (13.5 +/- 11.2 mg/L). No important alterations were noted in the concentrations of concomitantly administered antiepileptic drugs (AEDs) throughout the trial. VGB is useful adjuvant therapy for treatment of partial seizures. There may be a ceiling to effective dosage. This demands individual dose titration for each patient.
Published: 1993

20. Five years of anticonvulsant monitoring on site at the epilepsy clinic

Author: Martin J. Brodie, P. J. W. Mckee, I. W. Percy-Robb, A. F. Brodie, and J. G. Larkin
Subjects: Phenytoin, medicine.medical_specialty, Outpatient Clinics, Hospital, Time Factors, medicine.medical_treatment, Epilepsy, Pharmacokinetics, Internal medicine, medicine, Humans, Pharmacology (medical), Prospective Studies, Pharmacology, biology, business.industry, Valproic Acid, Carbamazepine, biology.organism_classification, medicine.disease, Drug concentration, Anticonvulsant, Scotland, Tasa, Anesthesia, Phenobarbital, Anticonvulsants, Drug Monitoring, business, medicine.drug
Abstract: The influence of antiepileptic drug monitoring on site at the epilepsy clinic was assessed in a prospective way by recording physicians' decisions before and after the drug concentration became available over the five-year period including 1986 to 1990. A total of 2,857 assays (1,121 carbamazepine, 798 phenytoin, 622 sodium valproate, and 72 phenobarbital) were performed during 2,696 hospital attendances on 618 epileptic patients. A gradual reduction in the proportion of visits monitored annually was observed (1986: 42%; 1987: 51%; 1988: 44%; 1989: 39%; 1990: 28%; p0.01). In 481 (17.8%) visits a change in management resulted from knowledge of the drug concentration. This was not an automatic response, as a large minority of unexpected results did not produce such an alteration. The proportion of decisions to adjust the drug dose after an unexpected result, however, tended to increase over the years of the study (1986: 43%; 1987: 70%; 1988: 60%; 1989: 78%; 1990: 54%; p0.01). Changes in anticonvulsant dose following an unexpected result were observed in "low" (59%), "therapeutic" (61%), and "high" (52%) concentration categories. Possible benefit for patients can be inferred from the observation that more assay results fell within the target range in the last (61%) compared with the first (33%) year of monitoring (p0.01).
Published: 1993

21. Managing seizures in the casualty department

Author: J. G. Larkin, Martin J. Brodie, J. A. Dawson, P. J. W. Mckee, and E. A. Wilson
Subjects: Adult, Male, Pediatrics, medicine.medical_specialty, Letter, Adolescent, MEDLINE, Epilepsy, Seizures, medicine, Humans, Child, Referral and Consultation, General Environmental Science, Aged, business.industry, General Engineering, General Medicine, Risk factor (computing), Middle Aged, medicine.disease, Hospitalization, Scotland, Emergency medicine, General Earth and Planetary Sciences, Anticonvulsants, Female, Emergencies, business, Emergency Service, Hospital, Research Article
Published: 1990

22. Myoclonic Epilepsy — Pitfalls in Diagnosis and Management

Author: J. G. Larkin, MartinJ. Brodie, P. J. W. Mckee, and G. McGinn
Subjects: Adult, Male, Phenytoin, Pediatrics, medicine.medical_specialty, Adolescent, Epilepsies, Myoclonic, 030204 cardiovascular system & hematology, Diagnosis, Differential, 03 medical and health sciences, 0302 clinical medicine, Seizures, medicine, Humans, 030212 general & internal medicine, business.industry, Valproic Acid, General Medicine, Carbamazepine, medicine.disease, Adult life, Myoclonic epilepsy, Female, business, medicine.drug
Abstract: Three cases of myoclonic epilepsy presenting in adolescence are described. Seizures were uninfluenced by treatment with carbamazepine. Substitution of sodium valproate in early adult life resulted in all becoming seizure-free. A high degree of clinical awareness is required in making the correct diagnosis and in choosing appropriate therapy for this form of epilepsy which can present with generalised tonic-clonic or partial seizures.
Published: 1991
Full Text: View/download PDF

23. Determination of beta-choriogonadotropin in human plasma; evaluation and comparison of five 'kit' methods

Author: J T France, P I Hair, J W McKee, and B S Knox
Subjects: Gynecology, medicine.medical_specialty, Analyte, business.operation, business.industry, Biochemistry (medical), Clinical Biochemistry, Trophoblastic Tumor, Radioimmunoassay, Mallinckrodt, Human plasma, medicine, business, Volume concentration
Abstract: We evaluated five quantitative, commercially available radioimmunoassay methods (Beta-Tec, BIO-RIA, Cambridge Nuclear, Mallinckrodt, and Serono) for rapid determination of the beta-subunit of human choriogonadotropin in serum or plasma. Only three of the kits (Beta-Tec, Mallinckrodt, and Serono) were found suitable for reliable determination of low concentrations of this analyte, which is of importance in the early diagnosis of trophoblastic disease in men and monitoring effectiveness of chemotherapy of trophoblastic tumors in men and women.
Published: 1980
Full Text: View/download PDF

24. Observations on the Kinetics and Control of Gas Core Reactors

Author: J. W. McKee and R. D. MacLain
Subjects: Nuclear and High Energy Physics, Fission products, Neutron economy, Materials science, Xenon-135, Nuclear Theory, Mechanics, Neutron temperature, Nuclear physics, Nuclear Energy and Engineering, Neutron cross section, Iodine pit, Neutron, Electrical and Electronic Engineering, Nuclear Experiment, Delayed neutron
Abstract: An expression is developed relating fission product residence time to fission product mass number for a hypothetical gas core vortex reactor. Utilizing the expression and considering that the fission products, Kr-87, Br-87, Kr-93, I-137, arid I-138, are also delayed neutron precursors, a modified effective delayed neutron fraction is calculated for U-233, U-235, and Pu-239 fueled cores. Temperature coefficients for the referene cores are developed as functions of reflector temperature, assuming a Maxwellian neutron spectrum. Utilizing these power coefficients and the modified effective delayed neutron fractions, the consequences of reactivity perturbations in the reference cores are analyzed. It is shown that optimally moderated gaseous fission cores should possess a high degree of inherent stability.
Published: 1962
Full Text: View/download PDF

25. Determination of beta-choriogonadotropin in human plasma; evaluation and comparison of five 'kit' methods

Author: B S, Knox, J W, McKee, P I, Hair, and J T, France
Subjects: Male, Macromolecular Substances, Reference Values, Radioimmunoassay, Humans, Female, Reagent Kits, Diagnostic, Luteinizing Hormone, Chorionic Gonadotropin
Abstract: We evaluated five quantitative, commercially available radioimmunoassay methods (Beta-Tec, BIO-RIA, Cambridge Nuclear, Mallinckrodt, and Serono) for rapid determination of the beta-subunit of human choriogonadotropin in serum or plasma. Only three of the kits (Beta-Tec, Mallinckrodt, and Serono) were found suitable for reliable determination of low concentrations of this analyte, which is of importance in the early diagnosis of trophoblastic disease in men and monitoring effectiveness of chemotherapy of trophoblastic tumors in men and women.
Published: 1980

26. Some physiological aspects of joints in health and disease. II. Physiology of abnormal joints

Author: G D, MASON, W A, SELLE, and J W, McKEE
Subjects: Health, Arthritis, Humans, Joints
Published: 1954

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources

Refine your results

26 results on '"J W McKee"'

1. Detection of quasi-periodic micro-structure in three millisecond pulsars with the Large European Array for Pulsars

2. Robust parameter estimation from pulsar timing data

3. The CHIME Pulsar Project: System Overview

4. A pulsar-based time-scale from the International Pulsar Timing Array

5. Dispersion measure variability for 36 millisecond pulsars at 150 MHz with LOFAR

6. Measuring Interstellar Delays of PSR J0613-0200 over 7 years, using the Large European Array for Pulsars

7. The International Pulsar Timing Array: Second data release

8. High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array

9. From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release

10. The International Pulsar Timing Array: First data release

11. A double-blind, placebo-controlled interaction study between oxcarbazepine and carbamazepine, sodium valproate and phenytoin in epileptic patients

12. Effect of vigabatrin on sedation and cognitive function in patients with refractory epilepsy

13. Double dummy comparison between once and twice daily dosing with modified-release carbamazepine in epileptic patients

14. Variability and clinical relevance of the interaction between sodium valproate and carbamazepine in epileptic patients

15. Rapid tolerance to acute psychomotor impairment with carbamazepine in epileptic patients

16. Nimodipine in refractory epilepsy: A placebo-controlled, add-on study

17. Physical and comparative mapping of distal mouse chromosome 16. 5 p5

18. Fragmentation and integrative modification of YACs

19. Adjuvant vigabatrin in refractory epilepsy: a ceiling to effective dosage in individual patients?

20. Five years of anticonvulsant monitoring on site at the epilepsy clinic

21. Managing seizures in the casualty department

22. Myoclonic Epilepsy — Pitfalls in Diagnosis and Management

23. Determination of beta-choriogonadotropin in human plasma; evaluation and comparison of five 'kit' methods

24. Observations on the Kinetics and Control of Gas Core Reactors

25. Determination of beta-choriogonadotropin in human plasma; evaluation and comparison of five 'kit' methods

26. Some physiological aspects of joints in health and disease. II. Physiology of abnormal joints

Catalog

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Journal

Database

Publisher

26 results on '"J W McKee"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources