The Astrophysical Journal (Jan 2024)
AGN STORM 2. V. Anomalous Behavior of the C iv Light Curve of Mrk 817
- Y. Homayouni,
- Gerard A. Kriss,
- Gisella De Rosa,
- Rachel Plesha,
- Edward M. Cackett,
- Michael R. Goad,
- Kirk T. Korista,
- Keith Horne,
- Travis Fischer,
- Tim Waters,
- Aaron J. Barth,
- Erin A. Kara,
- Hermine Landt,
- Nahum Arav,
- Benjamin D. Boizelle,
- Misty C. Bentz,
- Michael S. Brotherton,
- Doron Chelouche,
- Elena Dalla Bontà,
- Maryam Dehghanian,
- Pu Du,
- Gary J. Ferland,
- Carina Fian,
- Jonathan Gelbord,
- Catherine J. Grier,
- Patrick B. Hall,
- Chen Hu,
- Dragana Ilić,
- Michael D. Joner,
- Jelle Kaastra,
- Shai Kaspi,
- Andjelka B. Kovačević,
- Daniel Kynoch,
- Yan-Rong Li,
- Missagh Mehdipour,
- Jake A. Miller,
- Jake Mitchell,
- John Montano,
- Hagai Netzer,
- J. M. M. Neustadt,
- Ethan Partington,
- Luka Č. Popović,
- Daniel Proga,
- Thaisa Storchi-Bergmann,
- David Sanmartim,
- Matthew R. Siebert,
- Tommaso Treu,
- Marianne Vestergaard,
- Jian-Min Wang,
- Martin J. Ward,
- Fatima Zaidouni,
- Ying Zu
Affiliations
- Y. Homayouni
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; Department of Astronomy and Astrophysics, The Pennsylvania State University , 525 Davey Laboratory, University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Gerard A. Kriss
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Gisella De Rosa
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Rachel Plesha
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Edward M. Cackett
- ORCiD
- Department of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USA
- Michael R. Goad
- ORCiD
- School of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, UK
- Kirk T. Korista
- ORCiD
- Department of Physics, Western Michigan University , 1120 Everett Tower, Kalamazoo, MI 49008-5252, USA
- Keith Horne
- ORCiD
- SUPA School of Physics and Astronomy , North Haugh, St. Andrews KY16 9SS, Scotland, UK
- Travis Fischer
- ORCiD
- AURA for ESA, Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Tim Waters
- ORCiD
- Department of Physics & Astronomy, University of Nevada, Las Vegas , 4505 S. Maryland Parkway, Las Vegas, NV 89154-4002, USA
- Aaron J. Barth
- ORCiD
- Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California , Irvine, CA 92697-4575, USA
- Erin A. Kara
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research , Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Hermine Landt
- ORCiD
- Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE, UK
- Nahum Arav
- ORCiD
- Department of Physics , Virginia Tech, Blacksburg, VA 24061, USA
- Benjamin D. Boizelle
- ORCiD
- Department of Physics and Astronomy, N284 ESC, Brigham Young University , Provo, UT 84602, USA
- Misty C. Bentz
- ORCiD
- Department of Physics and Astronomy, Georgia State University , 25 Park Place, Suite 605, Atlanta, GA 30303, USA
- Michael S. Brotherton
- ORCiD
- Department of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USA
- Doron Chelouche
- ORCiD
- Department of Physics, Faculty of Natural Sciences, University of Haifa , Haifa 3498838, Israel; Haifa Research Center for Theoretical Physics and Astrophysics, University of Haifa , Haifa 3498838, Israel
- Elena Dalla Bontà
- ORCiD
- Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova , Vicolo dell’Osservatorio 3, I-35122 Padova, Italy; INAF-Osservatorio Astronomico di Padova , Vicolo dell’Osservatorio 5, I-35122 Padova, Italy
- Maryam Dehghanian
- ORCiD
- Department of Physics and Astronomy, The University of Kentucky , Lexington, KY 40506, USA
- Pu Du
- ORCiD
- Key Laboratory for Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, People's Republic of China
- Gary J. Ferland
- ORCiD
- Department of Physics and Astronomy, The University of Kentucky , Lexington, KY 40506, USA
- Carina Fian
- ORCiD
- Haifa Research Center for Theoretical Physics and Astrophysics, University of Haifa , Haifa 3498838, Israel; School of Physics and Astronomy and Wise observatory, Tel Aviv University , Tel Aviv 6997801, Israel
- Jonathan Gelbord
- ORCiD
- Spectral Sciences Inc. , 4 Fourth Avenue, Burlington, MA 01803, USA
- Catherine J. Grier
- ORCiD
- Department of Astronomy, University of Wisconsin-Madison , Madison, WI 53706, USA
- Patrick B. Hall
- ORCiD
- Department of Physics and Astronomy, York University , Toronto, ON M3J 1P3, Canada
- Chen Hu
- Key Laboratory for Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, People's Republic of China
- Dragana Ilić
- ORCiD
- University of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, Belgrade, Serbia; Hamburger Sternwarte, Universität Hamburg , Gojenbergsweg 112, D-21029 Hamburg, Germany
- Michael D. Joner
- ORCiD
- Department of Physics and Astronomy, N284 ESC, Brigham Young University , Provo, UT 84602, USA
- Jelle Kaastra
- ORCiD
- SRON Netherlands Institute for Space Research , Niels Bohrweg 4, 2333 CA Leiden, The Netherlands; Leiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The Netherlands
- Shai Kaspi
- ORCiD
- School of Physics and Astronomy and Wise observatory, Tel Aviv University , Tel Aviv 6997801, Israel
- Andjelka B. Kovačević
- ORCiD
- University of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, Belgrade, Serbia
- Daniel Kynoch
- ORCiD
- School of Physics and Astronomy, University of Southampton , Highfield, Southampton SO17 1BJ, UK; Astronomical Institute of the Czech Academy of Sciences , Boční II 1401, 141 00 Prague, Czechia
- Yan-Rong Li
- ORCiD
- Key Laboratory for Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, People's Republic of China
- Missagh Mehdipour
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Jake A. Miller
- ORCiD
- Department of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USA
- Jake Mitchell
- Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE, UK
- John Montano
- ORCiD
- Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California , Irvine, CA 92697-4575, USA
- Hagai Netzer
- ORCiD
- School of Physics and Astronomy and Wise observatory, Tel Aviv University , Tel Aviv 6997801, Israel
- J. M. M. Neustadt
- ORCiD
- Department of Astronomy, The Ohio State University , 140 West 18th Avenue, Columbus, OH 43210, USA
- Ethan Partington
- ORCiD
- Department of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USA
- Luka Č. Popović
- ORCiD
- University of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, Belgrade, Serbia; Astronomical Observatory , Volgina 7, 11060 Belgrade, Serbia
- Daniel Proga
- ORCiD
- Department of Physics & Astronomy, University of Nevada, Las Vegas , 4505 S. Maryland Parkway, Las Vegas, NV 89154-4002, USA
- Thaisa Storchi-Bergmann
- ORCiD
- Departamento de Astronomia—IF, Universidade Federal do Rio Grande do Sul , CP 150501, 91501-970 Porto Alegre, RS, Brazil
- David Sanmartim
- ORCiD
- Rubin Observatory Project Office , 950 N. Cherry Avenue, Tucson, AZ 85719, USA
- Matthew R. Siebert
- ORCiD
- Department of Astronomy and Astrophysics, University of California , Santa Cruz, CA 92064, USA
- Tommaso Treu
- ORCiD
- Department of Physics and Astronomy, University of California , Los Angeles, CA 90095, USA
- Marianne Vestergaard
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USA; DARK, The Niels Bohr Institute, University of Copenhagen , Jagtvej 155, DK-2200 Copenhagen, Denmark
- Jian-Min Wang
- ORCiD
- Key Laboratory for Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049, People's Republic of China; School of Astronomy and Space Sciences, University of Chinese Academy of Sciences , 19A Yuquan Road, Beijing 100049, People's Republic of China; National Astronomical Observatories of China , 20A Datun Road, Beijing 100020, People's Republic of China
- Martin J. Ward
- ORCiD
- Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE, UK
- Fatima Zaidouni
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research , Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Ying Zu
- ORCiD
- Department of Astronomy, School of Physics and Astronomy, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China; Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China
- DOI
- https://doi.org/10.3847/1538-4357/ad1be4
- Journal volume & issue
-
Vol. 963,
no. 2
p. 123
Abstract
An intensive reverberation mapping campaign of the Seyfert 1 galaxy Mrk 817 using the Cosmic Origins Spectrograph on the Hubble Space Telescope revealed significant variations in the response of broad UV emission lines to fluctuations in the continuum emission. The response of the prominent UV emission lines changes over an ∼60 day duration, resulting in distinctly different time lags in the various segments of the light curve over the 14 month observing campaign. One-dimensional echo-mapping models fit these variations if a slowly varying background is included for each emission line. These variations are more evident in the C iv light curve, which is the line least affected by intrinsic absorption in Mrk 817 and least blended with neighboring emission lines. We identify five temporal windows with a distinct emission-line response, and measure their corresponding time delays, which range from 2 to 13 days. These temporal windows are plausibly linked to changes in the UV and X-ray obscuration occurring during these same intervals. The shortest time lags occur during periods with diminishing obscuration, whereas the longest lags occur during periods with rising obscuration. We propose that the obscuring outflow shields the broad UV lines from the ionizing continuum. The resulting change in the spectral energy distribution of the ionizing continuum, as seen by clouds at a range of distances from the nucleus, is responsible for the changes in the line response.
Keywords
