2024-02-08 ミシガン大学
＜関連情報＞
- https://news.umich.edu/u-m-xxm-newton-spot-a-black-hole-giving-fierce-feedback/
- https://iopscience.iop.org/article/10.3847/2041-8213/ad1407
セイファート1.2銀河マーカリアン817のエディントン以下の暗黒状態における激しいフィードバック Fierce Feedback in an Obscured, Sub-Eddington State of the Seyfert 1.2 Markarian 817
Miranda K. Zak, Jon M. Miller, Ehud Behar, W. N. Brandt, Laura Brenneman, Paul A. Draghis, Elias Kammoun,, Michael J. Koss, Mark T. Reynolds,, and Abderahmen Zoghbi
The Astrophysical Journal Letters Published:2024 February 1
DOI:10.3847/2041-8213/ad1407
Abstract
Mrk 817 is a bright and variable Seyfert 1.2 active galactic nucleus (AGN). X-ray monitoring of Mrk 817 with the Neil Gehrels Swift Observatory in 2022 revealed that the source flux had declined to a lower level than recorded at any prior point in the then 19 yr mission. We present an analysis of deep XMM-Newton and NuSTAR observations obtained in this low flux state. The spectra reveal a complex X-ray wind consisting of neutral and ionized absorption zones. Three separate velocity components are detected as part of a structured ultrafast outflow (UFO), with v/c=0.043+0.007−0.003, v/c=0.079+0.003−0.0008, and v/c=0.074+0.004−0.005. These projected velocities suggest that the wind likely arises at radii that are much smaller than the optical broad-line region. In order for each component of the outflow to contribute significant feedback, the volume filling factors must be greater than f ≃ 0.009, f ≃ 0.003, and f ≃ 0.3, respectively. For plausible, data-driven volume filling factors, these limits are passed, and the total outflow likely delivers the fierce feedback required to reshape its host environment, despite a modest radiative Eddington fraction of λ ≃ 0.008–0.016 (this range reflects plausible masses). UFOs are often detected at or above the Eddington limit; this result signals that black hole accretion has the potential to shape host galaxies even at modest Eddington fractions and over a larger fraction of a typical AGN lifetime. We discuss our findings in terms of models for disk winds and black hole feedback in this and other AGN.
