AGN STORM 2. I. First results: A Change in the Weather of Mrk 817
Research output: Contribution to journal › Journal article › Research › peer-review
We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorption lines, which suggest that a dust-free, ionized obscurer located at the inner broad-line region partially covers the central source. Despite the obscuration, we measure UV and optical continuum reverberation lags consistent with a centrally illuminated Shakura-Sunyaev thin accretion disk, and measure reverberation lags associated with the optical broad-line region, as expected. However, in the first 55 days of the campaign, when the obscuration was becoming most extreme, we observe a de-coupling of the UV continuum and the UV broad emission-line variability. The correlation recovered in the next 42 days of the campaign, as Mrk 817 entered a less obscured state. The short C iv and Ly alpha lags suggest that the accretion disk extends beyond the UV broad-line region.
Original language | English |
---|---|
Article number | 151 |
Journal | Astrophysical Journal |
Volume | 922 |
Issue number | 2 |
Number of pages | 21 |
ISSN | 0004-637X |
DOIs | |
Publication status | Published - 26 Nov 2021 |
- ACTIVE GALACTIC NUCLEI, BROAD-LINE REGION, SUPERMASSIVE BLACK-HOLES, X-RAY REVERBERATION, DRIVEN DISK WINDS, SPACE TELESCOPE, ACCRETION-DISK, EMISSION-LINES, NGC 5548, LIGHT CURVES
Research areas
Links
- https://arxiv.org/pdf/2105.05840.pdf
Submitted manuscript
ID: 286491549