The Astrophysical Journal (Jan 2023)
AGN STORM 2. IV. Swift X-Ray and Ultraviolet/Optical Monitoring of Mrk 817
- Edward M. Cackett,
- Jonathan Gelbord,
- Aaron J. Barth,
- Gisella De Rosa,
- Rick Edelson,
- Michael R. Goad,
- Yasaman Homayouni,
- Keith Horne,
- Erin A. Kara,
- Gerard A. Kriss,
- Kirk T. Korista,
- Hermine Landt,
- Rachel Plesha,
- Nahum Arav,
- Misty C. Bentz,
- Benjamin D. Boizelle,
- Elena Dalla Bontà,
- Maryam Dehghanian,
- Fergus Donnan,
- Pu Du,
- Gary J. Ferland,
- Carina Fian,
- Alexei V. Filippenko,
- Diego H. González Buitrago,
- Catherine J. Grier,
- Patrick B. Hall,
- Chen Hu,
- Dragana Ilić,
- Jelle Kaastra,
- Shai Kaspi,
- Christopher S. Kochanek,
- Andjelka B. Kovačević,
- Daniel Kynoch,
- Yan-Rong Li,
- Jacob N. McLane,
- Missagh Mehdipour,
- Jake A. Miller,
- John Montano,
- Hagai Netzer,
- Christos Panagiotou,
- Ethan Partington,
- Luka Č. Popović,
- Daniel Proga,
- Daniele Rogantini,
- David Sanmartim,
- Matthew R. Siebert,
- Thaisa Storchi-Bergmann,
- Marianne Vestergaard,
- Jian-Min Wang,
- Tim Waters,
- Fatima Zaidouni
Affiliations
- Edward M. Cackett
- ORCiD
- Department of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USA ; [email protected]
- Jonathan Gelbord
- ORCiD
- Spectral Sciences Inc. , 30 Fourth Avenue, Suite 2, Burlington, MA 01803, USA
- Aaron J. Barth
- ORCiD
- Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California , Irvine, CA 92697-4575, USA
- Gisella De Rosa
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Rick Edelson
- ORCiD
- Eureka Scientific Inc. , 2452 Delmer Street Suite 100, Oakland, CA 94602, USA
- Michael R. Goad
- ORCiD
- School of Physics and Astronomy, University of Leicester , University Road, Leicester LE1 7RH, UK
- Yasaman 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
- Keith Horne
- ORCiD
- SUPA School of Physics and Astronomy , North Haugh, St. Andrews KY16 9SS, Scotland, UK
- Erin A. Kara
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Gerard A. Kriss
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Kirk T. Korista
- ORCiD
- Department of Physics, Western Michigan University , 1120 Everett Tower, Kalamazoo, MI 49008-5252, USA
- Hermine Landt
- Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE, UK
- Rachel Plesha
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Nahum Arav
- ORCiD
- Department of Physics , Virginia Tech, Blacksburg, VA 24061, USA
- Misty C. Bentz
- ORCiD
- Department of Physics and Astronomy, Georgia State University , 25 Park Place, Suite 605, Atlanta, GA 30303, USA
- Benjamin D. Boizelle
- ORCiD
- Department of Physics and Astronomy, N284 ESC, Brigham Young University , Provo, UT 84602, USA
- 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; Jeremiah Horrocks Institute, University of Central Lancashire , Preston PR1 2HE, UK
- Maryam Dehghanian
- ORCiD
- Department of Physics , Virginia Tech, Blacksburg, VA 24061, USA
- Fergus Donnan
- ORCiD
- Department of Physics, University of Oxford , Keble Road, Oxford OX1 3RH, UK
- 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
- Alexei V. Filippenko
- ORCiD
- Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
- Diego H. González Buitrago
- ORCiD
- Instituto de Astronomía, Universidad Nacional Autónoma de México , Km 103 Carretera Tijuana-Ensenada, 22860 Ensenada B.C., México
- 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, 11000 Belgrade, Serbia; Hamburger Sternwarte, Universität Hamburg , Gojenbergsweg 112, D-21029 Hamburg, Germany
- 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
- Christopher S. Kochanek
- ORCiD
- Department of Astronomy, The Ohio State University , 140 W. 18th Avenue, Columbus, OH 43210, USA; Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210, USA
- Andjelka B. Kovačević
- 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; University of Belgrade —Faculty of Mathematics, Department of Astronomy, Studentski trg 16, 11000 Belgrade, Serbia
- Daniel Kynoch
- ORCiD
- Astronomical Institute of the Czech Academy of Sciences , Boční II 1401/1a, CZ-14100 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
- Jacob N. McLane
- ORCiD
- Department of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USA
- 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 ; [email protected]
- 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
- Christos Panagiotou
- MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- Ethan Partington
- ORCiD
- Department of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USA ; [email protected]
- Luka Č. Popović
- 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; University of Belgrade —Faculty of Mathematics, Department of Astronomy, Studentski trg 16, 11000 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
- Daniele Rogantini
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- David Sanmartim
- ORCiD
- Carnegie Observatories , Las Campanas Observatory, Casilla 601, La Serena, Chile
- Matthew R. Siebert
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Thaisa Storchi-Bergmann
- ORCiD
- Departamento de Astronomia—IF, Universidade Federal do Rio Grande do Sul , CP 150501, 91501-970 Porto Alegre, RS, Brazil
- Marianne Vestergaard
- ORCiD
- Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721, USA; DARK, The Niels Bohr Institute, University of Copenhagen , Universitetsparken 5, DK-2100 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
- Tim Waters
- ORCiD
- Theoretical Division, Los Alamos National Laboratory , Los Alamos, NM, USA
- Fatima Zaidouni
- ORCiD
- MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
- DOI
- https://doi.org/10.3847/1538-4357/acfdac
- Journal volume & issue
-
Vol. 958,
no. 2
p. 195
Abstract
The AGN STORM 2 campaign is a large, multiwavelength reverberation mapping project designed to trace out the structure of Mrk 817 from the inner accretion disk to the broad emission line region and out to the dusty torus. As part of this campaign, Swift performed daily monitoring of Mrk 817 for approximately 15 months, obtaining observations in X-rays and six UV/optical filters. The X-ray monitoring shows that Mrk 817 was in a significantly fainter state than in previous observations, with only a brief flare where it reached prior flux levels. The X-ray spectrum is heavily obscured. The UV/optical light curves show significant variability throughout the campaign and are well correlated with one another, but uncorrelated with the X-rays. Combining the Swift UV/optical light curves with Hubble Space Telescope UV continuum light curves, we measure interband continuum lags, τ ( λ ), that increase with increasing wavelength roughly following τ ( λ ) ∝ λ ^4/3 , the dependence expected for a geometrically thin, optically thick, centrally illuminated disk. Modeling of the light curves reveals a period at the beginning of the campaign where the response of the continuum is suppressed compared to later in the light curve—the light curves are not simple shifted and scaled versions of each other. The interval of suppressed response corresponds to a period of high UV line and X-ray absorption, and reduced emission line variability amplitudes. We suggest that this indicates a significant contribution to the continuum from the broad-line region gas that sees an absorbed ionizing continuum.
Keywords