Our Lunch Talk of this week will be given by Dr. Le Nguyen Huynh Anh(阮惠安) at 11:00AM Thursday(June 20th) in the 19th-floor Observatory Hall (天文台报告厅).The title of the talk is “ Single epoch black hole masses based on the MgII and Hβ emission lines. "

Abstract:

Determining black hole masses (MBH) plays an important role in understanding the formation and evolution of active galactic nuclei (AGNs), since AGN energetics and their host galaxy properties are related to MBH. In this talk, I present the current calibration of MBH estimators based on the rest-frame ultraviolet (UV) and optical measurements of Mg II  2798 Å  and Hβ  4861 Å  lines and the AGN continuum, using a combination sample of 52 moderate-luminosity AGNs from Keck spectra and a larger luminosity sample from the Sloan Digital Sky Survey at z ∼  0.4 and z ∼  0.6.  The derived UV mass estimators typically show >∼ 0.2 dex intrinsic scatter with respect to the Hβ -based MBH , suggesting that the UV-based mass has an additional uncertainty of ∼ 0.2 dex, even if high-quality rest-frame UV spectra are available.

References:

https://iopscience.iop.org/article/10.1086/524349

https://iopscience.iop.org/article/10.3847/1538-4357/aabf3e