TY - JOUR
T1 - AGN STORM 2. VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations
AU - Dehghanian, Maryam
AU - Arav, Nahum
AU - Kriss, Gerard A.
AU - Mehdipour, Missagh
AU - Byun, Doyee
AU - Walker, Gwen
AU - Sharma, Mayank
AU - Barth, Aaron J.
AU - Bentz, Misty C.
AU - Boizelle, Benjamin D.
AU - Brotherton, Michael S.
AU - Cackett, Edward M.
AU - Dalla Bontà, Elena
AU - De Rosa, Gisella
AU - Ferland, Gary J.
AU - Fian, Carina
AU - Filippenko, Alexei V.
AU - Gelbord, Jonathan
AU - Goad, Michael R.
AU - Horne, Keith
AU - Homayouni, Yasaman
AU - Ilić, Dragana
AU - Joner, Michael D.
AU - Kara, Erin A.
AU - Kaspi, Shai
AU - Kochanek, Christopher S.
AU - Korista, Kirk T.
AU - Kosec, Peter
AU - Kovačević, Andjelka B.
AU - Landt, Hermine
AU - Lewin, Collin
AU - Partington, Ethan R.
AU - Popović, Luka
AU - Proga, Daniel
AU - Rogantini, Daniele
AU - Siebert, Matthew R.
AU - Storchi-Bergmann, Thaisa
AU - Vestergaard, Marianne
AU - Waters, Timothy
AU - Wang, Jian Min
AU - Zaidouni, Fatima
AU - Zu, Ying
N1 - Publisher Copyright:
© 2024. The Author(s). Published by the American Astronomical Society.
PY - 2024/9/1
Y1 - 2024/9/1
N2 - 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 N H = 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 U H = −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 n H > 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.
AB - 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 N H = 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 U H = −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 n H > 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.
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U2 - 10.3847/1538-4357/ad5ff4
DO - 10.3847/1538-4357/ad5ff4
M3 - Article
AN - SCOPUS:85203011560
SN - 0004-637X
VL - 972
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 141
ER -