| 报告题目： |
Direct Collapse to Supermassive Black Hole Seeds with Radiative Transfer |
| 报告人： |
罗阳 博士后 |
| 报告人单位： |
厦门大学 |
| 报告时间： |
东七楼427会议室 |
| 报告地点： |
4月25日 下午2:30-3:30 |
| 邀请人： |
吴庆文教授 |
| 报告人简介： |
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罗阳，厦门大学博⼠后
研究方向：
1. ⾼红移处超大质量黑洞的形成：数值模拟，中等质量黑洞形成，第⼀一代类星体形成；
2. 星系形成与演化: X射线观测, 星系际介质，星系反馈机制；
3. 高能现象：吸积盘，X射线双星，伽⻢马射线暴。 |
| 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 summary our results and show the possible observation implications.
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