Colloquium on Oct. 19, 2023

Research on High-velocity Broad Absorption Line Outflows in Quasars

Speaker: Zhicheng He (USTC)

Venue: SWIFAR Building 2111

Time: 15:00 PM, Thursday, Oct. 19, 2023

Abstract:

The outflows driven by the central black hole in active galaxies are considered one of the primary forms of active galactic nucleus feedback. The scale of the outflows is one of the key parameters for understanding their origin and measuring their impact on the galactic environment. The academic community generally believes that it can be reliably estimated by studying density-sensitive ionization-excited absorption lines. However, this traditional method has been limited to a few dozen active galaxies over the past three decades due to its technical complexity, uncertainty in results, and applicability only to narrow absorption lines without self-blending. Moreover, there has been controversy regarding the magnitude of the scales obtained. As a result, research on high-velocity outflows with broad absorption lines has progressed slowly in this field. The presenter has developed a new method for diagnosing the density of outflows based on the variability of absorption lines and has obtained unprecedented new results on high-velocity outflows using this method.

Report PPT:  SWIFAR_Zhicheng He.pptx