AGN STORM 2. II. Ultraviolet Observations of Mrk 817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope

0573378 - ASÚ 2024 RIV GB eng J - Článek v odborném periodiku
Homayouni, Y. - De Rosa, G. - Plesha, R. - Kynoch, Daniel … celkem 65 autorů
AGN STORM 2. II. Ultraviolet Observations of Mrk 817 with the Cosmic Origins Spectrograph on the Hubble Space Telescope.
Astrophysical Journal. Roč. 948, č. 2 (2023), č. článku 85. ISSN 0004-637X. E-ISSN 1538-4357
Institucionální podpora: RVO:67985815
Klíčová slova: active galactic nuclei * reverberation mapping * active galaxies
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 4.9, rok: 2022
Způsob publikování: Open access

We present reverberation mapping measurements for the prominent ultraviolet broad emission lines of the active
galactic nucleus Mrk 817 using 165 spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space
Telescope. Our ultraviolet observations are accompanied by X-ray, optical, and near-infrared observations as part
of the AGN Space Telescope and Optical Reverberation Mapping Program 2 (AGN STORM 2). Using the cross-
correlation lag analysis method, we find significant correlated variations in the continuum and emission-line light
curves. We find that the emission-line responses to continuum variations are more complex than a simple smoothed, shifted, and scaled version of the continuum light curve. We also measure velocity-resolved lags for the Lyα and C IV emission lines.
The lag profile in the blue wing of Lyα is consistent with virial motion, with longer lags dominating at lower
velocities, and shorter lags at higher velocities. The C IV lag profile shows the signature of a thick rotating disk,
with the shortest lags in the wings, local peaks at ±1500 km s−1 , and a local minimum at the line center. The other
emission lines are dominated by broad absorption lines and blending with adjacent emission lines. These require
detailed models, and will be presented in future work.
Trvalý link: https://hdl.handle.net/11104/0343842