Abstract
We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/ Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs extending over 14 yr. We conclude that, while the narrow absorption outflow system (at −3750 km s−1 with FWHM = 177 km s−1) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (log NH = 19.5 - +0.13 0.61 cm−2) did not change across all epochs. The adjusted ionization parameter (scaled with respect to the variations in the hydrogen-ionizing continuum flux) is log UH = −1.0 - +0.3 0.1. The outflow is located at a distance smaller than 38 pc from the central source, which implies a hydrogen density of nH > 3000 cm−3 . The absorption outflow system only covers the continuum emission source and not the broad emission line region, which suggests that its transverse size is small (< 10 16 cm), with potential cloud geometries ranging from spherical to elongated along the line of sight.
Document Type
Article
Publication Date
2024
Digital Object Identifier (DOI)
https://doi.org/10.3847/1538-4357/ad5ff4
Funding Information
We express our appreciation to the anonymous reviewer whose feedback has contributed to the enhancement of this manuscript. All of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via 10.17909/16n2-nt70. Our project began with the successful Cycle 28 HST proposal 16196 (Peterson et al. 2020). M.D, N.A, D.B, G.W, and M.Sh acknowledge support from NSF grant AST 2106249, as well as NASA STScI grants AR- 15786, AR-16600, AR-16601, and HST-AR-17556. E.M.C. gratefully acknowledges support from NASA through grant 80NSSC22 K0089. Y.H. acknowledges support from the Hubble Space Telescope program GO-16196, provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. C.S.K. is supported by NSF grant AST- 2307385. M.C.B. gratefully acknowledges support from the NSF through grant AST-2009230. H.L. acknowledges a Daphne Jackson Fellowship sponsored by the Science and Technology Facilities Council (STFC), UK. D.I., A.B.K, and L.Č.P. acknowledge funding provided by the University of Belgrade- Faculty of Mathematics (contract 451-03-66/2024-03/200104), Astronomical Observatory Belgrade (contract 451-03-66/2024- 03/200002), through grants by the Ministry of Education, Science, and Technological Development of the Republic of Serbia. D.I. acknowledges the support of the Alexander von Humboldt Foundation. A.B.K. and L.Č.P. are thankful for the support by Chinese Academy of Sciences Presidentʼs International Fellowship Initiative (PIFI) for visiting scientists. A.V.F. is grateful for financial assistance from the Christopher R. Redlich Fund and numerous individual donors. M.V. gratefully acknowledges support from the Independent Research Fund Denmark via grant No. DFF 8021-00130. CSK is supported by NSF grants AST-2307385 and AST-1908570. M.R.S. is supported by the STScI Postdoctoral Fellowship. P.K. acknowledges support from NASA through the NASA Hubble Fellowship grant HST-HF2-51534.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. J.G. gratefully acknowledges support from NASA through the grant 80NSSC22K1492.
Repository Citation
Dehghanian, Maryam; Arav, Nahum; Kriss, Gerard A.; Mehdipour, Missagh; Byun, Doyee; Walker, Gwen; Sharma, Mayank; Barth, Aaron J.; Bentz, Misty C.; Boizelle, Benjamin D.; Brotherton, Michael S.; Cackett, Edward M.; Bontà, Elena Dalla; De Rosa, Gisella; Ferland, Gary; Fian, Carina; Filippenko, Alexei V.; Gelbord, Jonathan; Goad, Michael R.; Horne, Keith; Homayouni, Yasaman; Ilić, Dragana; Joner, Michael D.; Kara, Erin A.; Kaspi, Shai; Kochanek, Christopher S.; Korista, Kirk T.; Kosec, Peter; Kovačević, Andjelka B.; Landt, Hermine; Lewin, Collin; Partington, Ethan R.; Popović, Luka Č.; Proga, Daniel; Rogantini, Daniele; Siebert, Matthew R.; Storchi-Bergmann, Thaisa; Vestergaard, Marianne; Waters, Timothy; Wang, Jian-Min; Zaidouni, Fatima; and Zu, Ying, "AGN STORM 2. VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations" (2024). Physics and Astronomy Faculty Publications. 688.
https://uknowledge.uky.edu/physastron_facpub/688
Notes/Citation Information
© 2024. The Author(s). Published by the American Astronomical Society.