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1. Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548

Author

B. J. Shappee, J. M. Gelbord, Alessandro Siviero, Marianne Vestergaard, M. Spencer, G. A. Borman, Kevin V. Croxall, Michael Fausnaugh, Rick Edelson, M. C. Bottorff, Yair Krongold, Jeremy Jones, A. Skielboe, Nicolas Tejos, T. Hutchison, F. MacInnis, J. E. Brown, Catherine J. Grier, Hyun-Il Sung, M. L. Nguyen, Ryan Norris, Alis J. Deason, Haojing Yan, Susanna Bisogni, D. M. Crenshaw, J. A. Kennea, Alexei V. Filippenko, P. Ochner, S. V. Nazarov, A. A. Breeveld, Keith Horne, I. M. McHardy, Y. Weiss, E. Holmbeck, Wei Zhu, Michael T. Carini, J. A. Nousek, Hagai Netzer, A. Bigley, S. Hicks, Michael D. Joner, Kirk T. Korista, S. A. Klimanov, S. C. Kim, G. De Rosa, Jon C. Mauerhan, E. R. Manne-Nicholas, J. van Saders, Isaac Shivvers, Aaron J. Barth, Christopher S. Kochanek, Vardha N. Bennert, Ying Zu, Sang Chul Kim, Kelly D. Denney, Scott M. Adams, S. G. Sergeev, L. Gonzalez, F. Müller Sánchez, H. Yuk, Steven Villanueva, N. Gehrels, J. J. Jensen, R. McGurk, M. Im, Miao Li, K. Flatland, Garrett Somers, Jamie Tayar, D. Mudd, S. Geier, Enrico Maria Corsini, Phil Uttley, S. Rafter, M. Eracleous, H. W. Rix, Lorenzo Morelli, Douglas C. Leonard, Kelsey I. Clubb, Laura Vican, K. Schnülle, Smita Mathur, C. S. Turner, J. R. Parks, J.-U. Pott, M. Dietrich, Patrick L. Kelly, Jenny E. Greene, Carolin Villforth, P. Arévalo, Calen B. Henderson, Michael S. Brotherton, A. Gupta, M. W. Lau, Julia M. Comerford, Chris Done, Minjin Kim, Ori D. Fox, Gerard A. Kriss, Gary J. Ferland, Daniel Proga, S. Young, N. V. Efimova, Thomas W.-S. Holoien, P. A. Evans, Radosław Poleski, M. R. Goad, Dirk Grupe, B. Scott, Alessandro Pizzella, Zhiyuan Ma, J. S. Schimoia, J. C. Lee, Jong-Hak Woo, P. Lira, Cassandra Lochhaas, Jessie C. Runnoe, M. H. Siegel, Justin Ely, Patrick B. Hall, I. E. Papadakis, C. A. Johnson, Tommaso Treu, Emma Gardner, Todd Boroson, D. A. Starkey, Daniel J. Stevens, Thomas G. Beatty, Andrew J. King, Jelle Kaastra, Edward M. Cackett, Misty C. Bentz, J. S. Brown, Liuyi Pei, D. N. Okhmat, Steve Croft, M. A. Malkan, G. V. Simonian, M. Dehghanian, C. Montuori, Bradley M. Peterson, E. Dalla Bontà, R. W. Pogge, Matthew T. Penny, V. Gorjian, W. N. Brandt, Elinor L. Gates, Shai Kaspi, D. A. Saylor, Ana M. Mosquera, A. Pancoast, WeiKang Zheng, A. de Lorenzo-Cáceres, Gabriela Canalizo, ITA, USA, GBR, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
Seyfert [Galaxies], Active galactic nucleus, active [Galaxies], 010504 meteorology & atmospheric sciences, individual (NGC 5548) [Galaxies], Active galaxies, Astrophysical black holes, Supermassive black holes, Active galactic nuclei, Reverberation mapping, astro-ph.GA, T-NDAS, FOS: Physical sciences, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Atomic, Physical Chemistry, Virial theorem, Reverberation mapping, Particle and Plasma Physics, Spitzer Space Telescope, Supermassive black holes, 0103 physical sciences, QB Astronomy, Nuclear, Emission spectrum, 010303 astronomy & astrophysics, QC, QB, 0105 earth and related environmental sciences, Line (formation), Physics, Active galactic nuclei, Supermassive black hole, Astrophysical black holes, Molecular, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Black hole, QC Physics, Space and Planetary Science, nuclei [Galaxies], Astrophysics of Galaxies (astro-ph.GA), Active galaxies, Astronomical and Space Sciences, Physical Chemistry (incl. Structural)
Abstract

We report velocity-delay maps for prominent broad emission lines, Ly_alpha, CIV, HeII and H_beta, in the spectrum of NGC5548. The emission-line responses inhabit the interior of a virial envelope. The velocity-delay maps reveal stratified ionization structure. The HeII response inside 5-10 light-days has a broad single-peaked velocity profile. The Ly_alpha, CIV, and H_beta responses peak inside 10 light-days, extend outside 20 light-days, and exhibit a velocity profile with two peaks separated by 5000 km/s in the 10 to 20 light-day delay range. The velocity-delay maps show that the M-shaped lag vs velocity structure found in previous cross-correlation analysis is the signature of a Keplerian disk with a well-defined outer edge at R=20 light-days. The outer wings of the M arise from the virial envelope, and the U-shaped interior of the M is the lower half of an ellipse in the velocity-delay plane. The far-side response is weaker than that from the near side, so that we see clearly the lower half, but only faintly the upper half, of the velocity--delay ellipse. The delay tau=(R/c)(1-sin(i))=5 light-days at line center is from the near edge of the inclined ring, giving the inclination i=45 deg. A black hole mass of M=7x10^7 Msun is consistent with the velocity-delay structure. A barber-pole pattern with stripes moving from red to blue across the CIV and possibly Ly_alpha line profiles suggests the presence of azimuthal structure rotating around the far side of the broad-line region and may be the signature of precession or orbital motion of structures in the inner disk. Further HST observations of NGC 5548 over a multi-year timespan but with a cadence of perhaps 10 days rather than 1 day could help to clarify the nature of this new AGN phenomenon., 19 pages, 9 figures, ApJ in press

Published
2021

2. Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

Author

Andrew J. King, K. G. Teems, Gabriele Ponti, J. S. Schimoia, Calen B. Henderson, Michael S. Brotherton, S. Paltani, Nahum Arav, Alessandro Siviero, Radosław Poleski, P. Lira, Sang Chul Kim, Thomas W.-S. Holoien, Wei Zhu, A. de Lorenzo-Cáceres, M. C. Bottorff, Dirk Grupe, Gabriela Canalizo, M. Eracleous, S. G. Sergeev, F. MacInnis, Massimo Cappi, M. Dietrich, Alis J. Deason, Haojing Yan, Giorgio Matt, Ciro Pinto, Michael T. Carini, Minjin Kim, Brandon C. Kelly, I. M. McHardy, Scott M. Adams, L. Gonzalez, J. J. Jensen, Julia M. Comerford, Yair Krongold, Tim Waters, B. Scott, C. S. Turner, G. A. Borman, R. McGurk, Nicolas Tejos, J. R. Parks, K. Flatland, Michael D. Joner, Kirk T. Korista, L. Di Gesu, Emma Gardner, Jon C. Mauerhan, Jessie C. Runnoe, Douglas C. Leonard, Kelsey I. Clubb, M. H. Siegel, C. A. Johnson, D. A. Starkey, H. Yuk, M. A. Malkan, Justin Ely, Ying Zu, Aaron J. Barth, Cassandra Lochhaas, Patrick L. Kelly, E. Holmbeck, Hyun-Il Sung, Patrick B. Hall, C. Montuori, Christopher S. Kochanek, Bradley M. Peterson, Tommaso Treu, Missagh Mehdipour, Marie Wingyee Lau, A. Skielboe, Catherine J. Grier, J. A. Kennea, Thomas G. Beatty, R. W. Pogge, J. van Saders, A. Bigley, S. Hicks, Catia Silva, H. W. Rix, Vardha N. Bennert, D. M. Crenshaw, E. Dalla Bontà, Miao Li, A. A. Breeveld, Dom Walton, D. N. Okhmat, Elisa Costantini, P. Ochner, Y. Weiss, M. L. Nguyen, Ryan Norris, Susanna Bisogni, Ehud Behar, Jacobo Ebrero, Garrett Somers, Phil Uttley, S. Rafter, Kelly D. Denney, K. Schnülle, Carolin Villforth, Keith Horne, Smita Mathur, G. V. Simonian, R. Boissay-Malaquin, Gary J. Ferland, J. S. Brown, Jelle Kaastra, Ana M. Mosquera, Stefano Bianchi, Misty C. Bentz, A. Pancoast, Alessandro Pizzella, WeiKang Zheng, N. Gehrels, Daniel J. Stevens, M. Dehghanian, Kevin V. Croxall, Isaac Shivvers, A. Gupta, Chris Done, J. E. Brown, B. De Marco, Gerard A. Kriss, Steve Croft, S. V. Nazarov, J. A. Nousek, Jae-Ok Lee, P. Arévalo, G. De Rosa, Michael Fausnaugh, Rick Edelson, Phil Evans, Lorenzo Morelli, S. Geier, Enrico Maria Corsini, M. R. Goad, V. Gorjian, W. N. Brandt, Elinor L. Gates, Shai Kaspi, D. A. Saylor, Jong-Hak Woo, Edward M. Cackett, Liuyi Pei, T. Hutchison, Jamie Tayar, E. R. Manne-Nicholas, Laura Vican, Daniel Proga, Steven Villanueva, D. Mudd, J.-U. Pott, F. Müller-Sánchez, Alexei V. Filippenko, Hagai Netzer, S. A. Klimanov, B. J. Shappee, J. M. Gelbord, Marianne Vestergaard, M. Spencer, Zhiyuan Ma, Carl T. Coker, S. Y. Kim, Myungshin Im, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), Kriss, G. A., De Rosa, G., Ely, J., Peterson, B. M., Kaastra, J., Mehdipour, M., Ferland, G. J., Dehghanian, M., Mathur, S., Edelson, R., Korista, K. T., Arav, N., Barth, A. J., Bentz, M. C., Brandt, W. N., Crenshaw, D. M., Bontà, E. Dalla, Denney, K. D., Done, C., Eracleous, M., Fausnaugh, M. M., Gardner, E., Goad, M. R., Grier, C. J., Horne, Keith, Kochanek, C. S., Mchardy, I. M., Netzer, H., Pancoast, A., Pei, L., Pogge, R. W., Proga, D., Silva, C., Tejos, N., Vestergaard, M., Adams, S. M., Anderson, M. D., Arévalo, P., Beatty, T G., Behar, E., Bennert, V. N., Bianchi, S., Bigley, A., Bisogni, S., Boissay-Malaquin, R., Borman, G. A., Bottorff, M. C., Breeveld, A. A., Brotherton, M., Brown, J. E., Brown, J. S., Cackett, E. M., Canalizo, G., Cappi, M., Carini, M. T., Clubb, K. I., Comerford, J. M., Coker, C. T., Corsini, E. M., Costantini, E., Croft, S., Croxall, K. V., Deason, A. J., De Lorenzo-Cáceres, A., De Marco, B., Dietrich, M., Di Gesu, L., Ebrero, J., Evans, P. A., Filippenko, A. V., Flatland, K., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Gonzalez, L., Gorjian, V., Grupe, D., Gupta, A., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -S., Hutchison, T. A., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Kaspi, S., Kelly, B. C., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S. C., Kim, S. Y., King, A., Klimanov, S. A., Krongold, Y., Lau, M. W., Lee, J. C., Leonard, D. C., Li, Miao, Lira, P., Lochhaas, C., Ma, Zhiyuan, Macinnis, F., Malkan, M. A., Manne-Nicholas, E. R., Matt, G., Mauerhan, J. C., Mcgurk, R., Montuori, C., Morelli, L., Mosquera, A., Mudd, D., Müller-Sánchez, F., Nazarov, S. V., Norris, R. P., Nousek, J. A., Nguyen, M. L., Ochner, P., Okhmat, D. N., Paltani, S., Parks, J. R., Pinto, C., Pizzella, A., Poleski, R., Ponti, G., Pott, J. -U., Rafter, S. E., Rix, H. -W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnülle, K., Scott, B., Sergeev, S. G., Shappee, B. J., Shivvers, I., Siegel, M., Simonian, G. V., Siviero, A., Skielboe, A., Somers, G., Spencer, M., Starkey, D., Stevens, D. J., Sung, H. -I., Tayar, J., Teems, K. G., Treu, T., Turner, C. S., Uttley, P., Van Saders, J ., Vican, L., Villforth, C., Villanueva Jr., S., Walton, D. J., Waters, T., Weiss, Y., Woo, J. -H., Yan, H., Yuk, H., Zheng, W., Zhu, W., Zu, Y., and USA

Subjects
Seyfert [Galaxies], galaxies: active, galaxies: individual (NGC 5548), galaxies: nuclei, galaxies: Seyfert, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, active [Galaxies], individual (NGC 5548) [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, Continuum (design consultancy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Luminosity, 0103 physical sciences, QB Astronomy, Emission spectrum, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Physics, Astronomy and Astrophysics, DAS, Astrophysics - Astrophysics of Galaxies, Galaxy, QC Physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), nuclei [Galaxies], Reverberation mapping
Abstract

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC~5548 obtained with the Hubble Space Telescope during the 6-month reverberation-mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Ly$\alpha$ and C IV, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Ly$\alpha$ and C IV have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show delayed response to continuum variations corresponding to recombination in gas with a density of $\sim 10^5~\rm cm^{-3}$. The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in $\sim\,2012$ corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state., Comment: 50 pages, 30 figures, uses aastex62.cls. Accepted for publication in ApJ, 07/06/2019. High-level products page in MAST will go live after 7/15/2019. Replaced Figure 4 on 7/12/2019 to be more red/green color-blind friendly

Published
2019
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3. Space Telescope and Optical Reverberation Mapping Project. XII: Broad-line Region Modeling of NGC 5548

Author

Christopher S. Kochanek, T. Hutchison, H. W. Rix, Gary J. Ferland, Alessandro Pizzella, E. Holmbeck, E. R. Manne-Nicholas, Ori D. Fox, Radosław Poleski, I. E. Papadakis, Erin Kara, S. Young, Vardha N. Bennert, Kelly D. Denney, Daniel J. Stevens, M. Dietrich, Calen B. Henderson, WeiKang Zheng, Haojing Yan, Aaron J. Barth, P. Lira, M. C. Bottorff, Steve Croft, Jelle Kaastra, Jamie Tayar, Misty C. Bentz, Zhiyuan Ma, Laura Vican, Jenny E. Greene, J. S. Brown, M. W. Lau, F. Müller-Sánchez, Alexei V. Filippenko, Dirk Grupe, Daniel Proga, R. McGurk, Alis J. Deason, I. M. McHardy, K. Flatland, Matthew A. Malkan, Michael D. Joner, Douglas C. Leonard, Kelsey I. Clubb, Missagh Mehdipour, B. J. Shappee, Kevin V. Croxall, J. M. Gelbord, M. H. Siegel, Jon C. Mauerhan, Ying Zu, Patrick L. Kelly, Christian Knigge, Myungshin Im, Peter R. Williams, C. A. Johnson, S. V. Nazarov, J. A. Nousek, Miao Li, C. S. Turner, Andrew J. King, Marianne Vestergaard, S. C. Kim, G. De Rosa, J. R. Parks, M. Spencer, S. G. Sergeev, Steven Villanueva, Matthew T. Penny, Lorenzo Morelli, Jong-Hak Woo, D. Mudd, D. M. Crenshaw, J.-U. Pott, T. W. S. Holoien, A. A. Breeveld, D. N. Okhmat, Scott M. Adams, Carolin Villforth, Sang Chul Kim, V. Gorjian, W. N. Brandt, G. V. Simonian, Elinor L. Gates, Shai Kaspi, M. Dehghanian, D. A. Saylor, Hyun-Il Sung, Simon Vaughan, Isaac Shivvers, F. MacInnis, Minjin Kim, Edward M. Cackett, Liuyi Pei, Alessandro Siviero, Cassandra Lochhaas, Patrick B. Hall, Wei Zhu, Tommaso Treu, Thomas G. Beatty, Tim Waters, B. Scott, J. C. Lee, Jeremy Jones, M. L. Nguyen, Ryan Norris, Susanna Bisogni, Justin Ely, Keith Horne, A. Gupta, L. Gonzalez, J. J. Jensen, P. Arévalo, N. Gehrels, Catherine J. Grier, S. Geier, Enrico Maria Corsini, S. E. Rafter, P. Ochner, Y. Weiss, A. Skielboe, Michael T. Carini, Michael S. Brotherton, H. Yuk, Chris Done, Gerard A. Kriss, C. Montuori, Bradley M. Peterson, E. Dalla Bontà, Emma Gardner, D. A. Starkey, R. W. Pogge, Smita Mathur, J. A. Kennea, P. A. Evans, A. Bigley, Jessie C. Runnoe, S. Hicks, S. A. Klimanov, Todd Boroson, J. van Saders, J. S. Schimoia, Garrett Somers, Phil Uttley, Nahum Arav, G. A. Borman, J. E. Brown, Nicolas Tejos, Julia M. Comerford, A. de Lorenzo-Cáceres, Gabriela Canalizo, Ana M. Mosquera, A. Pancoast, Michael Fausnaugh, Rick Edelson, N. V. Efimova, Brendon J. Brewer, Yair Krongold, High Energy Astrophys. & Astropart. Phys (API, FNWI), University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, ITA, USA, and GBR

Subjects
010504 meteorology & atmospheric sciences, Active galaxies, Active galactic nuclei, Reverberation mapping, Seyfert galaxies, Astrophysics, 01 natural sciences, Atomic, Particle and Plasma Physics, Reverberation mapping, Spitzer Space Telescope, Emission spectrum, 010303 astronomy & astrophysics, QC, Physics, Seyfert galaxies, Balmer series, 3rd-DAS, VARIABILITY, Reverbation mapping, AGN MONITORING PROJECT, symbols, STEPS, Astronomical and Space Sciences, Physical Chemistry (incl. Structural), Active galactic nucleus, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Electromagnetic radiation, symbols.namesake, SUPERMASSIVE BLACK-HOLES, 0103 physical sciences, Nuclear, MASSES, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Active galactic nuclei, Molecular, Astronomy and Astrophysics, Light curve, Astrophysics - Astrophysics of Galaxies, Black hole, CONTINUUM, SIZE, QC Physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Active galaxies, EMISSION
Abstract

We present geometric and dynamical modeling of the broad line region for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The dataset includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the H$\beta$, C IV, and Ly$\alpha$ broad emission lines. We find an extended disk-like H$\beta$ BLR with a mixture of near-circular and outflowing gas trajectories, while the C IV and Ly$\alpha$ BLRs are much less extended and resemble shell-like structures. There is clear radial structure in the BLR, with C IV and Ly$\alpha$ emission arising at smaller radii than the H$\beta$ emission. Using the three lines, we make three independent black hole mass measurements, all of which are consistent. Combining these results gives a joint inference of $\log_{10}(M_{\rm BH}/M_\odot) = 7.64^{+0.21}_{-0.18}$. We examine the effect of using the $V$ band instead of the UV continuum light curve on the results and find a size difference that is consistent with the measured UV-optical time lag, but the other structural and kinematic parameters remain unchanged, suggesting that the $V$ band is a suitable proxy for the ionizing continuum when exploring the BLR structure and kinematics. Finally, we compare the H$\beta$ results to similar models of data obtained in 2008 when the AGN was at a lower luminosity state. We find that the size of the emitting region increased during this time period, but the geometry and black hole mass remain unchanged, which confirms that the BLR kinematics suitably gauge the gravitational field of the central black hole., Comment: 26 pages, 19 figures, 1 table, accepted for publication in ApJ

Published
2020
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4. Constraints on the broad line region from regularized linear inversion: velocity–delay maps for five nearby active galactic nuclei

Author

Misty C. Bentz, Anna Pancoast, A. Skielboe, Tommaso Treu, Aaron J. Barth, and Daeseong Park

Subjects
Active galactic nucleus, 010504 meteorology & atmospheric sciences, astro-ph.GA, Astrophysics::High Energy Astrophysical Phenomena, statistical [methods], nuclei [galaxies], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinematics, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, 0103 physical sciences, Astronomical And Space Sciences, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Supermassive black hole, Principle of maximum entropy, Astronomy, Astronomy and Astrophysics, Inversion (meteorology), Light curve, Astrophysics - Astrophysics of Galaxies, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), active [galaxies], Reverberation mapping
Abstract

Reverberation mapping probes the structure of the broad emission-line region (BLR) in active galactic nuclei (AGN). The kinematics of the BLR gas can be used to measure the mass of the central supermassive black hole. The main uncertainty affecting black hole mass determinations is the structure of the BLR. We present a new method for reverberation mapping based on regularized linear inversion (RLI) that includes modelling of the AGN continuum light curves. This enables fast calculation of velocity-resolved response maps to constrain BLR structure. RLI allows for negative response, such as when some areas of the BLR respond in inverse proportion to a change in ionizing continuum luminosity. We present time delays, integrated response functions, and velocity-delay maps for the $\rm{H}\,\beta$ broad emission line in five nearby AGN, as well as for $\rm{H}\,\alpha$ and $\rm{H}\,\gamma$ in Arp 151, using data from the Lick AGN Monitoring Project 2008. We find indications of prompt response in three of the objects (Arp 151, NGC 5548 and SBS 1116+583A) with additional prompt response in the red wing of $\rm{H}\,\beta$. In SBS 1116+583A we find evidence for a multimodal broad prompt response followed by a second narrow response at 10 days. We find no clear indications of negative response. The results are complementary to, and consistent with, other methods such as cross correlation, maximum entropy and dynamical modelling. Regularized linear inversion with continuum light curve modelling provides a fast, complementary method for velocity-resolved reverberation mapping and is suitable for use on large datasets., Comment: 20 pages, 13 figures, accepted to MNRAS

Published
2015
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5. Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548

Author

S. Young, Brandon C. Kelly, J.-U. Pott, T. Hutchison, Scott M. Adams, E. Holmbeck, A. A. Breeveld, Jelle Kaastra, S. E. Rafter, Misty C. Bentz, G. A. Borman, P. Arévalo, D. A. Starkey, Michael T. Carini, I. E. Papadakis, M. Dietrich, Alis J. Deason, I. M. McHardy, Vardha N. Bennert, Kelly D. Denney, Michael D. Joner, Gabriela Canalizo, Justin Ely, A. Pancoast, Catherine J. Grier, D. C. Leonard, P. Ochner, Ying Zu, Zhiyuan Ma, A. Skielboe, J. van Saders, Bryan Scott, D. Horenstein, J. A. Kennea, Carl T. Coker, W. N. Brandt, A. Gupta, H. Yuk, D. Grupe, M. C. Bottorff, Michael Fausnaugh, Myungshin Im, Marianne Vestergaard, Rick Edelson, K. Schnülle, M. Spencer, Sang Chul Kim, C. Montouri, Miao Li, J. J. Jensen, W. Zheng, Nadia L. Zakamska, Gary J. Ferland, Ana M. Mosquera, N. V. Efimova, Steve Croft, Jenny E. Greene, Michael Eracleous, A. de Lorenzo-Cáceres, M. R. Goad, D. A. Saylor, Richard W. Pogge, Calen B. Henderson, Radosław Poleski, Jessie C. Runnoe, Carolin Villforth, G. De Rosa, A. V. Filippenko, Ori D. Fox, M. W. Lau, Thomas W.-S. Holoien, Michael S. Brotherton, H. Yan, Kirk T. Korista, C. Bazhaw, E. M. Cackett, B. Ou-Yang, Hagai Netzer, K. G. Teems, Michael A. Strauss, Aaron J. Barth, Alessandro Pizzella, Jon C. Mauerhan, Steven Villanueva, Christopher S. Kochanek, J. C. Lee, R. McGurk, M. H. Siegel, K. Flatland, F. Muller Sanchez, D. Mudd, Nicolas Tejos, Elinor L. Gates, P. Lira, Kelsey I. Clubb, S. V. Nazarov, Lorenzo Morelli, R. Musso, Cassandra Lochhaas, Patrick B. Hall, H.-I. Sung, Matthew T. Penny, Tommaso Treu, D. M. Crenshaw, H.-W. Rix, Bradley M. Peterson, Daniel J. Stevens, D. N. Okhmat, Patrick L. Kelly, Thomas G. Beatty, M. L. Nguyen, Ryan Norris, S. Mathur, Susanna Bisogni, Isaac Shivvers, S. Geier, Keith Horne, Phil Evans, G. V. Simonian, E. Dalla Bontà, Benjamin J. Shappee, A. L. King, Shai Kaspi, Enrico Maria Corsini, G. A. Kriss, C. S. Turner, J. R. Parks, Y. Weiss, M. Malkan, E. R. Manne-Nicholas, Jonathan Gelbord, Alessandro Siviero, Wei Zhu, S. G. Sergeev, F. MacInnis, Minjin Kim, J. A. Nousek, Cassidy Johnson, J. S. Brown, A. Bigley, S. Hicks, Julia M. Comerford, J. D. Jones, J. S. Schimoia, Jamie Tayar, K. V. Croxall, Laura Vican, Jong-Hak Woo, Garrett Somers, Phil Uttley, Liuyi Pei, N. Gehrels, J. E. Brown, Stacy Y. Kim, S. A. Klimanov, USA, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Doubly ionized oxygen, NDAS, nuclei [galaxies], FOS: Physical sciences, Astrophysics, Expected value, galaxies: active - galaxies: individual (NGC 5548) - galaxies: nuclei - galaxies: Seyfert, medicine.disease_cause, 01 natural sciences, Spitzer Space Telescope, Seyfert [galaxies], 0103 physical sciences, medicine, QB Astronomy, Emission spectrum, 010303 astronomy & astrophysics, QC, QB, Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Light curve, Astrophysics - Astrophysics of Galaxies, Monitoring program, QC Physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), active [galaxies], individual (NGC 5548) [galaxies], Reverberation mapping, Ultraviolet
Abstract

We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multi-wavelength reverberation mapping campaign. The campaign spanned six months and achieved an almost daily cadence with observations from five ground-based telescopes. The H$\beta$ and He II $\lambda$4686 broad emission-line light curves lag that of the 5100 $\AA$ optical continuum by $4.17^{+0.36}_{-0.36}$ days and $0.79^{+0.35}_{-0.34}$ days, respectively. The H$\beta$ lag relative to the 1158 $\AA$ ultraviolet continuum light curve measured by the Hubble Space Telescope is roughly $\sim$50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-line region is $\sim$50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for H$\beta$ and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the H$\beta$ and He II $\lambda$4686 emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for C IV, Ly $\alpha$, He II(+O III]), and Si IV(+O IV]) during the same monitoring period. Finally, given the optical luminosity of NGC 5548 during our campaign, the measured H$\beta$ lag is a factor of five shorter than the expected value implied by the $R_\mathrm{BLR} - L_\mathrm{AGN}$ relation based on the past behavior of NGC 5548., Comment: 22 pages, 13 figures, accepted to ApJ

Published
2017
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6. Space Telescope and Optical Reverberation Mapping Project. IV. Anomalous Behavior of the Broad Ultraviolet Emission Lines in NGC 5548

Author

Goad, M. R., Korista, K. T., De Rosa, G., Kriss, G. A., Edelson, R., Barth, A. J., Ferland, G. J., Kochanek, C. S., Netzer, H., Peterson, B. M., Bentz, M. C., Bisogni, S., Crenshaw, D. M., Denney, K. D., Ely, J., Fausnaugh, M. M., Grier, C. J., Gupta, A., Horne, K. D., Kaastra, J., Pancoast, A., Pei, L., Pogge, R. W., Skielboe, A., Starkey, D., Vestergaard, M., Zu, Y., Anderson, M. D., Arevalo, P., Bazhaw, C., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brewer, B. J., Cackett, E. M., Carini, M. T., Croxall, K. V., Bonta, E. Dalla, de Lorenzo-Caceres, A., Dietrich, M., Efimova, N. V., Evans, P. A., Filippenko, A. V., Flatland, K., Gehrels, N., Geier, S., Gelbord, G. M., Gonzalez, L., Gorjian, V., Grupe, D., Hall, P. B., Hicks, S., Horenstein, D., Hutchison, T., Im, M., Jensen, J. J., Joner, M. D., Jones, J., Kaspi, S., Kelly, B. C., Kennea, J. A., Kim, M., Kim, S. C., Klimanov, S. A., Larionov, V. M., Lee, J. C., Leonard, D. C., Lira, P., MacInnis, F., Manne-Nicholas, E. R., Mathur, S., McHardy, I. M., Montouri, C., Musso, R., Nazarov, S. V., Norris, R. P., Nousek, J. A., Okhmat, D. N., Papadakis, I., Parks, J. R., Pott, J. -U., Rafter, S. E., Rix, H. -W., Saylor, D. A., Schimoia, J. S., Schnulle, K., Sergeev, S. G., Siegel, M., Spencer, M., Sung, H. -I., Teems, K. G., Treu, T., Turner, C. S., Uttley, P., Villforth, C., Weiss, Y., Woo, J. -H., Yan, H., Young, S., Zheng, W. -K., High Energy Astrophys. & Astropart. Phys (API, FNWI), Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, ITA, USA, and GBR

Subjects
Active galactic nucleus, 010504 meteorology & atmospheric sciences, Cosmic Origins Spectrograph, active [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, galaxies: individual (NGC-5548), galaxies: nuclei, galaxies: Seyfert Supporting material: animation, Continuum (design consultancy), Doubly ionized oxygen, NDAS, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, QB Astronomy, Emission spectrum, Seyfert Supporting material: animation [Galaxies], 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, QB, Galáxia NGC 5548, Physics, individual (NGC – 5548) [Galaxies], active, galaxies: individual (NGC, 5548), galaxies: nuclei, galaxies: Seyfert [galaxies], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxias seyfert, Galaxy, Galáxias ativas, QC Physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), nuclei [Galaxies], individual (NGC-5548) [Galaxies], Reverberation mapping, Equivalent width, Nucleo galatico
Abstract

During an intensive Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) UV monitoring campaign of the Seyfert~1 galaxy NGC 5548 performed from 2014 February to July, the normally highly correlated far-UV continuum and broad emission-line variations decorrelated for ~60 to 70 days, starting ~75 days after the first HST/COS observation. Following this anomalous state, the flux and variability of the broad emission lines returned to a more normal state. This transient behavior, characterised by significant deficits in flux and equivalent width of the strong broad UV emission lines, is the first of its kind to be unambiguously identified in an active galactic nucleus reverberation mapping campaign. The largest corresponding emission-line flux deficits occurred for the high-ionization collisionally excited lines, C IV and Si IV(+O IV]), and also He II(+O III]), while the anomaly in Ly-alpha was substantially smaller. This pattern of behavior indicates a depletion in the flux of photons with E_{\rm ph} > 54 eV, relative to those near 13.6 eV. We suggest two plausible mechanisms for the observed behavior: (i) temporary obscuration of the ionizing continuum incident upon BLR clouds by a moving veil of material lying between the inner accretion disk and inner BLR, perhaps resulting from an episodic ejection of material from the disk, or (ii) a temporary change in the intrinsic ionizing continuum spectral energy distribution resulting in a deficit of ionizing photons with energies > 54 eV, possibly due to a transient restructuring of the Comptonizing atmosphere above the disk. Current evidence appears to favor the latter explanation., 12 pages, 2 figures, accepted for publication in ApJ, Friday 25th March 2016. A movie of the anomalous emission-line behavior can be found in the ancilliary documents

Published
2016
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7. Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

Author

Mathur, S., Gupta, A., Page, K., Pogge, R. W., Krongold, Y., Goad, M. R., Adams, S. M., Anderson, M. D., Arã©valo, P., Barth, A. J., Bazhaw, C., Beatty, T. G., Bentz, M. C., Bigley, A., Bisogni, S., Borman, G. A., Boroson, T. A., Bottorff, M. C., Brandt, W. N., Breeveld, A. A., Brown, J. E., Brown, J. S., Cackett, E. M., Canalizo, G., Carini, M. T., Clubb, K. I., Comerford, J. M., Coker, C. T., Corsini, E. M., Crenshaw, D. M., Croft, S., Croxall, K. V., Dalla Bontã , E., Deason, A. J., Denney, K. D., De Lorenzo-cã¡ceres, A., De Rosa, G., Dietrich, M., Edelson, R., Ely, J., Eracleous, M., Evans, P. A., Fausnaugh, M. M., Ferland, G. J., Filippenko, A. V., Flatland, K., Fox, O. D., Gates, E. L., Gehrels, N., Geier, S., Gelbord, J. M., Gorjian, V., Greene, J. E., Grier, C. J., Grupe, D., Hall, P. B., Henderson, C. B., Hicks, S., Holmbeck, E., Holoien, T. W. -. S., Horenstein, D., Horne, Keith, Hutchison, T., Im, M., Jensen, J. J., Johnson, C. A., Joner, M. D., Jones, J., Kaastra, J., Kaspi, S., Kelly, B. C., Kelly, P. L., Kennea, J. A., Kim, M., Kim, S., Kim, S. C., King, A., Klimanov, S. A., Kochanek, C. S., Korista, K. T., Kriss, G. A., Lau, M. W., Lee, J. C., Leonard, D. C., Li, M., Lira, P., Ma, Z., Macinnis, F., Manne-nicholas, E. R., Malkan, M. A., Mauerhan, J. C., Mcgurk, R., Mchardy, I. M., Montouri, C., Morelli, L., Mosquera, A., Mudd, D., Muller-sanchez, F., Musso, R., Nazarov, S. V., Netzer, H., Nguyen, M. L., Norris, R. P., Nousek, J. A., Ochner, P., Okhmat, D. N., Ou-yang, B., Pancoast, A., Papadakis, I., Parks, J. R., Pei, L., Peterson, B. M., Pizzella, A., Poleski, R., Pott, J. -. U., Rafter, S. E., Rix, H. -. W., Runnoe, J., Saylor, D. A., Schimoia, J. S., Schnã¼lle, K., Sergeev, S. G., Shappee, B. J., Shivvers, I., Siegel, M., Simonian, G. V., Siviero, A., Skielboe, A., Somers, G., Spencer, M., Starkey, D., Stevens, D. J., Sung, H. -. I., Tayar, J., Tejos, N., Turner, C. S., Uttley, P., Van Saders, J., Vestergaard, M., Vican, L., Villanueva, S., Villforth, C., Weiss, Y., Woo, J. -. H., Yan, H., Young, S., Yuk, H., Zheng, W., Zhu, W., Zu, Y., Corsini, ENRICO MARIA, USA, High Energy Astrophys. & Astropart. Phys (API, FNWI), Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
active [Galaxies], individual (NGC 5548) [Galaxies], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Continuum (design consultancy), FOS: Physical sciences, Flux, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Spectral line, individual (NGC 5548) [X-rays], galaxies: individual (NGC 5548), X-rays: galaxies, X-rays: individual (NGC 5548), Astronomy and Astrophysics, Space and Planetary Science, Spitzer Space Telescope, 0103 physical sciences, QB Astronomy, Emission spectrum, 010303 astronomy & astrophysics, QC, Optical depth, QB, Physics, 010308 nuclear & particles physics, 3rd-DAS, Astrophysics - Astrophysics of Galaxies, galaxies [X-rays], QC Physics, 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), Reverberation mapping, Anomaly (physics)
Abstract

During the Space Telescope and Optical Reverberation Mapping Project (STORM) observations of NGC 5548, the continuum and emission-line variability became de-correlated during the second half of the 6-month long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as a part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than being due to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all the three observations: the UV emission line flux decrease, the soft-excess increase, and the emission line anomaly., ApJ in press. Replaced with the accepted version

Published
2017
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8. SPATIAL ANISOTROPY OF GALAXY KINEMATICS IN SLOAN DIGITAL SKY SURVEY GALAXY CLUSTERS

Author

Radosław Wojtak, Kristian Pedersen, Eli S. Rykoff, Eduardo Rozo, and A. Skielboe

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), media_common.quotation_subject, FOS: Physical sciences, Velocity dispersion, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Kinematics, Astrophysics, Galaxy, Azimuth, Space and Planetary Science, Sky, Cluster (physics), Anisotropy, Astrophysics::Galaxy Astrophysics, Galaxy cluster, Astrophysics - Cosmology and Nongalactic Astrophysics, media_common
Abstract

Measurements of galaxy cluster kinematics are important in understanding the dynamical state and evolution of clusters of galaxies, as well as constraining cosmological models. While it is well established that clusters exhibit non-spherical geometries, evident in the distribution of galaxies on the sky, azimuthal variations of galaxy kinematics within clusters have yet to be observed. Here we measure the azimuthal dependence of the line-of-sight velocity dispersion profile in a stacked sample of 1743 galaxy clusters from the Sloan Digital Sky Survey (SDSS). The clusters are drawn from the SDSS DR8 redMaPPer catalog. We find that the line-of-sight velocity dispersion of galaxies lying along the major axis of the central galaxy is larger than those that lie along the minor axis. This is the first observational detection of anisotropic kinematics of galaxies in clusters. We show that the result is consistent with predictions from numerical simulations. Furthermore we find that the degree of projected anisotropy is strongly dependent on the line-of-sight orientation of the galaxy cluster, opening new possibilities for assessing systematics in optical cluster finding., 6 pages, 4 figures; final version as published in ApJ Letters

Published
2012
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9. MEASURING THE THREE-DIMENSIONAL SHAPE OF X-RAY CLUSTERS

Author

Johan Samsing, A. Skielboe, and Steen Honoré Hansen

Subjects
Physics, Line-of-sight, Space and Planetary Science, Cluster (physics), Astronomy and Astrophysics, Circular symmetry, Measure (mathematics), Rotation (mathematics), Power law, Galaxy cluster, Spectral line, Computational physics
Abstract

Observations and numerical simulations of galaxy clusters strongly indicate that the hot intracluster X-ray-emitting gas is not spherically symmetric. In many earlier studies, spherical symmetry has been assumed partly because of limited data quality; however, new deep observations and instrumental designs will make it possible to go beyond that assumption. Measuring the temperature and density profiles are of interest when observing the X-ray gas; however, the spatial shape of the gas itself also carries very useful information. For example, it is believed that the X-ray gas shape in the inner parts of galaxy clusters is greatly affected by feedback mechanisms, cooling, and rotation, and measuring this shape can therefore indirectly provide information on these mechanisms. In this paper, we present a novel method to measure the three-dimensional shape of the intracluster X-ray-emitting gas. We can measure the shape from X-ray observations only, i.e., the method does not require combination with independent measurements of, e.g., the cluster mass or density profile. This is possible when one uses the full spectral information contained in the observed spectra. We demonstrate the method by measuring radially dependent shapes along the line of sight for CHANDRA mock data. We find that at least 106 photons are required to get a 5σ detection of shape for an X-ray gas having realistic features such as a cool core and a double power law for the density profile. We illustrate how Bayes' theorem is used to find the best-fitting model of the X-ray gas, an analysis that is very important in a real observational scenario where the true spatial shape is unknown. Not including a shape in the fit may propagate to a mass bias if the X-ray is used to estimate the total cluster mass. We discuss this mass bias for a class of spatial shapes.

Published
2012
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10. Simulations of the OzDES AGN Reverberation Mapping Project

Author

Christopher S. Kochanek, Tamara M. Davis, Richard G. McMahon, A. L. King, Bradley M. Peterson, A. Skielboe, Kelly D. Denney, Marianne Vestergaard, Manda Banerji, C. Lidman, Paul Martini, E. M. Huff, Darach Watson, and Rob Sharp

Subjects
Physics, Active galactic nucleus, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Quasar, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Lambda, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Redshift, Supernova, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Dark energy, Reverberation mapping, Emission spectrum, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

As part of the OzDES spectroscopic survey we are carrying out a large scale reverberation mapping study of $\sim$500 quasars over five years in the 30 deg$^2$ area of the Dark Energy Survey (DES) supernova fields. These quasars have redshifts ranging up to 4 and have apparent AB magnitudes between $16.8, Comment: Published online in MNRAS. 28 pages

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