1. AGN STORM 2. VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations*
- Author
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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., Dalla Bontà, Elena, De Rosa, Gisella, Ferland, Gary J., 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, Zu, Ying, 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., Dalla Bontà, Elena, De Rosa, Gisella, Ferland, Gary J., 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
- 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 (< 1016 cm), with potential cloud geometries ranging from spherical to elongated along the line of sight.
- Published
- 2024
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