Title:  Downtown Andromeda: A Multiwavelength Study of The Nearest LINER

　  Speaker: Dr. Zhiyuan Li (Harvard-Smithsonian CfA)

Time: 2:00pm, Dec. 16

Location: 3rd floor, middle conferecen room

Abstract:

The so-called nuclear spiral in the Andromeda galaxy (M31), consisting of ionized and neutral dusty gas clouds of typically sub-parsec sizes, shows optical emission lines characteristic of LINERs. Yet the lack of UV radiation from either an active nucleus or massive young stars makes the ionizing source of this nearest LINER a longstanding puzzle. I will give an observational overview of the circumnuclear region of M31, and present preliminary results of  an on-going multiwavelength study, based on new and archival HST, Spitzer and Chandra observations. I will discuss the relative importance of various ionization/excitation mechanisms, in particular heating by energetic particles that are plausibly supplied by the dormant super-massive black hole. This study will advance our understanding of the physical regulation of galactic circumnuclear environments.