AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817

The local ( z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed mod...

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Main Authors: Hagai Netzer, Michael R. Goad, Aaron J. Barth, Edward M. Cackett, Keith Horne, Chen Hu, Erin Kara, Kirk T. Korista, Gerard A. Kriss, Collin Lewin, John Montano, Nahum Arav, Ehud Behar, Michael S. Brotherton, Doron Chelouche, Gisella De Rosa, Elena Dalla Bontà, Maryam Dehghanian, Gary J. Ferland, Carina Fian, Yasaman Homayouni, Dragana Ilić, Shai Kaspi, Andjelka B. Kovačević, Hermine Landt, Luka Č. Popović, Thaisa Storchi-Bergmann, Jian-Min Wang, Fatima Zaidouni
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Language:English
Published: IOP Publishing 2024-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/ad8160
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author Hagai Netzer
Michael R. Goad
Aaron J. Barth
Edward M. Cackett
Keith Horne
Chen Hu
Erin Kara
Kirk T. Korista
Gerard A. Kriss
Collin Lewin
John Montano
Nahum Arav
Ehud Behar
Michael S. Brotherton
Doron Chelouche
Gisella De Rosa
Elena Dalla Bontà
Maryam Dehghanian
Gary J. Ferland
Carina Fian
Yasaman Homayouni
Dragana Ilić
Shai Kaspi
Andjelka B. Kovačević
Hermine Landt
Luka Č. Popović
Thaisa Storchi-Bergmann
Jian-Min Wang
Fatima Zaidouni
author_facet Hagai Netzer
Michael R. Goad
Aaron J. Barth
Edward M. Cackett
Keith Horne
Chen Hu
Erin Kara
Kirk T. Korista
Gerard A. Kriss
Collin Lewin
John Montano
Nahum Arav
Ehud Behar
Michael S. Brotherton
Doron Chelouche
Gisella De Rosa
Elena Dalla Bontà
Maryam Dehghanian
Gary J. Ferland
Carina Fian
Yasaman Homayouni
Dragana Ilić
Shai Kaspi
Andjelka B. Kovačević
Hermine Landt
Luka Č. Popović
Thaisa Storchi-Bergmann
Jian-Min Wang
Fatima Zaidouni
author_sort Hagai Netzer
collection DOAJ
description The local ( z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed modeling of the broad line region (BLR), several types of disk winds classified by their optical depth, and new numerical simulations. We find that diffuse continuum (DC) emission, with additional contributions from strong and broad emission lines, can explain the continuum lags observed in this source during high- and low-luminosity phases. Disk illumination by the variable X-ray corona contributes only a small fraction of the observed continuum lags. Our BLR models assume radiation-pressure-confined clouds distributed over a distance of 2–122 light days. We present calculated mean emissivity radii of many emission lines, and DC emission, and suggest a simple, transfer-function-dependent method that ties them to cross-correlation lag determinations. We do not find clear indications for large-optical-depth winds, but identify the signature of lower-column-density winds. In particular, we associate the shortest observed continuum lags with a combination of τ (1 Ryd) ≈ 2 wind and a partly shielded BLR. Even smaller optical depth winds may be associated with X-ray absorption features and with noticeable variations in the widths and lags of several high-ionization lines like He ii and C iv . Finally, we demonstrate the effect of torus dust emission on the observed lags in the i and z bands.
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spelling doaj-art-596cf6efe99e41ea86147f8aecdb67462025-08-20T02:14:34ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0197615910.3847/1538-4357/ad8160AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817Hagai Netzer0https://orcid.org/0000-0002-6766-0260Michael R. Goad1https://orcid.org/0000-0002-2908-7360Aaron J. Barth2https://orcid.org/0000-0002-3026-0562Edward M. Cackett3https://orcid.org/0000-0002-8294-9281Keith Horne4https://orcid.org/0000-0003-1728-0304Chen Hu5Erin Kara6https://orcid.org/0000-0003-0172-0854Kirk T. Korista7https://orcid.org/0000-0003-0944-1008Gerard A. Kriss8https://orcid.org/0000-0002-2180-8266Collin Lewin9https://orcid.org/0000-0002-8671-1190John Montano10https://orcid.org/0000-0001-5639-5484Nahum Arav11https://orcid.org/0000-0003-2991-4618Ehud Behar12https://orcid.org/0000-0001-9735-4873Michael S. Brotherton13https://orcid.org/0000-0002-1207-0909Doron Chelouche14Gisella De Rosa15https://orcid.org/0000-0003-3242-7052Elena Dalla Bontà16https://orcid.org/0000-0001-9931-8681Maryam Dehghanian17https://orcid.org/0000-0002-0964-7500Gary J. Ferland18https://orcid.org/0000-0003-4503-6333Carina Fian19https://orcid.org/0000-0002-2306-9372Yasaman Homayouni20https://orcid.org/0000-0002-0957-7151Dragana Ilić21https://orcid.org/0000-0002-1134-4015Shai Kaspi22https://orcid.org/0000-0002-9925-534XAndjelka B. Kovačević23https://orcid.org/0000-0001-5139-1978Hermine Landt24Luka Č. Popović25https://orcid.org/0000-0003-2398-7664Thaisa Storchi-Bergmann26https://orcid.org/0000-0003-1772-0023Jian-Min Wang27https://orcid.org/0000-0001-9449-9268Fatima Zaidouni28https://orcid.org/0000-0003-0931-0868School of Physics and Astronomy, Tel Aviv University , Tel Aviv 6997801, IsraelSchool of Physics and Astronomy, University of Leicester , University Road, Leicester, LE1 7RH, UKDepartment of Physics and Astronomy, 4129 Frederick Reines Hall University of California , Irvine, CA 92697-4575, USADepartment of Physics and Astronomy, Wayne State University , 666 W. Hancock Street, Detroit, MI 48201, USASUPA School of Physics and Astronomy , North Haugh, St. Andrews, KY16 9SS, Scotland, UKKey Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences , 19B Yuquan Road, Beijing 100049, People's Republic of ChinaMIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USADepartment of Physics, Western Michigan University , 1120 Everett Tower, Kalamazoo, MI 49008-5252, USASpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USAMIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USADepartment of Physics and Astronomy, 4129 Frederick Reines Hall University of California , Irvine, CA 92697-4575, USADepartment of Physics , Virginia Tech, Blacksburg, VA 24061, USAMIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USA; Department of Physics , Technion, Haifa 32000, IsraelDepartment of Physics and Astronomy, University of Wyoming , Laramie, WY 82071, USADepartment 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, IsraelSpace Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USADipartimento 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, UKDepartment of Physics , Virginia Tech, Blacksburg, VA 24061, USADepartment of Physics and Astronomy, The University of Kentucky , Lexington, KY 40506, USADepartamento de Astronomía y Astrofísica, Universidad de Valencia , E-46100 Burjassot, Valencia, Spain; Observatorio Astronómico, Universidad de Valencia , E-46980 Paterna, Valencia, SpainSpace 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, USAUniversity of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, 11000 Belgrade, Serbia; Hamburger Sternwarte, Universität Hamburg , Gojenbergsweg 112, 21029 Hamburg, GermanySchool of Physics and Astronomy and Wise Observatory, Tel Aviv University , Tel Aviv 6997801, IsraelUniversity of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, 11000 Belgrade, SerbiaCentre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham, DH1 3LE, UKUniversity of Belgrade—Faculty of Mathematics , Department of Astronomy, Studentski trg 16, 11000 Belgrade, Serbia; Astronomical Observatory , Volgina 7, 11060 Belgrade, SerbiaDepartamento de Astronomia—IF, Universidade Federal do Rio Grande do Sul , CP 150501, 91501-970 Porto Alegre, RS, BrazilKey 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 ChinaMIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology , Cambridge, MA 02139, USAThe local ( z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed modeling of the broad line region (BLR), several types of disk winds classified by their optical depth, and new numerical simulations. We find that diffuse continuum (DC) emission, with additional contributions from strong and broad emission lines, can explain the continuum lags observed in this source during high- and low-luminosity phases. Disk illumination by the variable X-ray corona contributes only a small fraction of the observed continuum lags. Our BLR models assume radiation-pressure-confined clouds distributed over a distance of 2–122 light days. We present calculated mean emissivity radii of many emission lines, and DC emission, and suggest a simple, transfer-function-dependent method that ties them to cross-correlation lag determinations. We do not find clear indications for large-optical-depth winds, but identify the signature of lower-column-density winds. In particular, we associate the shortest observed continuum lags with a combination of τ (1 Ryd) ≈ 2 wind and a partly shielded BLR. Even smaller optical depth winds may be associated with X-ray absorption features and with noticeable variations in the widths and lags of several high-ionization lines like He ii and C iv . Finally, we demonstrate the effect of torus dust emission on the observed lags in the i and z bands.https://doi.org/10.3847/1538-4357/ad8160Galaxy accretion disksSupermassive black holesEmission line galaxiesReverberation mappingActive galactic nuclei
spellingShingle Hagai Netzer
Michael R. Goad
Aaron J. Barth
Edward M. Cackett
Keith Horne
Chen Hu
Erin Kara
Kirk T. Korista
Gerard A. Kriss
Collin Lewin
John Montano
Nahum Arav
Ehud Behar
Michael S. Brotherton
Doron Chelouche
Gisella De Rosa
Elena Dalla Bontà
Maryam Dehghanian
Gary J. Ferland
Carina Fian
Yasaman Homayouni
Dragana Ilić
Shai Kaspi
Andjelka B. Kovačević
Hermine Landt
Luka Č. Popović
Thaisa Storchi-Bergmann
Jian-Min Wang
Fatima Zaidouni
AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
The Astrophysical Journal
Galaxy accretion disks
Supermassive black holes
Emission line galaxies
Reverberation mapping
Active galactic nuclei
title AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
title_full AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
title_fullStr AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
title_full_unstemmed AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
title_short AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
title_sort agn storm 2 x the origin of the interband continuum delays in mrk 817
topic Galaxy accretion disks
Supermassive black holes
Emission line galaxies
Reverberation mapping
Active galactic nuclei
url https://doi.org/10.3847/1538-4357/ad8160
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