题 目：Multi-band HST mapping of dusty clouds in the nuclear bulge of M31
报告人：Dr. Hui Dong
National Optical Astronomy Observatory
摘 要：Our understanding of the whole universe is anchored on the knowledge of the local universe. As the biggest galaxy in the Local Group, the Andromeda galaxy (M31) provides us with a good lab to understand the star formation process, constrain the stellar evolutionary model and study the star clusters. Because of its importance, a Hubble Multi-Cycle Treasury program with more than 800 orbits has been dedicated to study 1/3 of the M31.
By using the six band images in this survey, plus the observations at the other four filters taken also by Hubble Space telescope, we study the interstellar material in the circum-nuclear region of the M31 which still remains poorly understood.
We present a map of dusty clouds in the central ∼ 4x4 square arcmin region, constructed pixel-by-pixel via ﬁtting the spectral energy distribution (SED). We also tend to estimate the line-of-sight location of selected clouds, as well as their sizes, densities, and their projected spatial distribution. These results have strong implications for understanding the formation and destruction processes of dusty gas in the circum-nuclear region of the galaxy.