【学术报告】
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报告题目：Direct Collapse to Supermassive Black Hole Seeds with Radiative Transfer

报告人：罗阳

报告人单位：厦门大学

报告时间：2019年4月4日（周四）上午 09:30-10:30

报告地点：主楼228室

报告语言：中文

报告摘要： 

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　　A growing number of quasars found at redshifts z~6, when the universe was younger than a gigayear, requires a very efficient way of forming early supermassive black holes. The main difficulty in forming the SMBHs in galaxy centers is their long growth time, if the initial seed mass is small compared to the final product. In this talk, I will briefly introduce the direct collapse scenarios, in which gas accumulates and collapses to form an SMBH seed either with or without the intermediate stage of an super-massive star. I will show my recent work by testing this assumption by treating the optically thick part of the accretion flow using radiative transfer in the flux-limited diffusion (FLD) approximation. We follow the flow as the radiation pressure builds up and becomes as important as the gas thermal pressure.  As a result, we find that the collapse proceeds in a filamentary way, and is nearly isothermal in the outer part,down to~ 1e-4 1e-3 pc from the center. Inside the optically-thick region, a central object forms in response to the converging flow and is delineated by its photosphere, initially ~ 1e-6 pc and expanding thereafter. I will summarize our results and show the possible observation implications.

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http://www.ynao.cas.cn/xwzx/xstg/ 

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云台邀请团组：自由探索组

邀请方联系人：焦承亮，18387124205

3月6日