2024-06-11 ペンシルベニア州立大学(PennState)
＜関連情報＞
- https://www.psu.edu/news/eberly-college-science/story/astronomers-find-unexpected-accelerating-quasar-winds-around-distant/
- https://iopscience.iop.org/article/10.3847/1538-4357/ad429e
SDSS-Vブラックホールマッパー残響マッピングプロジェクト： クェーサー SBS 1408+544 における C iv ブロード吸収線の加速 The SDSS-V Black Hole Mapper Reverberation Mapping Project: C iv Broad Absorption Line Acceleration in the Quasar SBS 1408+544
Robert Wheatley, Catherine J. Grier, Patrick B. Hall, W. N. Brandt, Jonah Lotz, D. P. Schneider, Jonathan R. Trump, Yue Shen, Lucas M. Seaton, Scott F. Anderson
The Astrophysical Journal Published: 2024 June 11
DOI:10.3847/1538-4357/ad429e
Abstract
We present the results of an investigation of a highly variable C iv broad absorption line (BAL) feature in spectra of the quasar SBS 1408+544 (z = 2.337) that shows a significant shift in velocity over time. This source was observed as a part of the Sloan Digital Sky Survey (SDSS) Reverberation Mapping project and the SDSS-V Black Hole Mapper Reverberation Mapping project, and has been included in two previous studies, both of which identified significant variability in a high-velocity C iv BAL on timescales of just a few days in the quasar rest frame. Using ∼130 spectra acquired over 8 yr of spectroscopic monitoring with SDSS, we have determined that this BAL is not only varying in strength, but is also systematically shifting to higher velocities. Using cross-correlation methods, we measure the velocity shifts (and corresponding acceleration) of the BAL over a wide range of timescales, measuring an overall velocity shift of Δ=−683+89−84 km s−1 over the 8 yr monitoring period. This corresponds to an average rest-frame acceleration of a = 1.04+0.14−0.13 cm s−2, though the magnitude of the acceleration on shorter timescales is not constant throughout. We place our measurements in the context of BAL-acceleration models and examine various possible causes of the observed velocity shift.
