feedback limits rapid growth seed bhs at high redshift
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Feedback Limits Rapid Growth Seed BHs at High Redshift. Jianmin Wang, Yanmei Chen , Chen Hu Institute of High Energy Physics. Outline. Background and Motivation Growth: Feedback Limit Radiation pressure Compton heating Outflow Discussion Conclusion. Background: observations.

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feedback limits rapid growth seed bhs at high redshift

Feedback Limits Rapid Growth Seed BHs at High Redshift

Jianmin Wang,Yanmei Chen, Chen Hu

Institute of High Energy Physics

outline
Outline
  • Background and Motivation
  • Growth: Feedback Limit

Radiation pressure

Compton heating

Outflow

  • Discussion
  • Conclusion
background observations
Background: observations
  • Early reionization epoch needs a large population of BHs
  • SDSS indicates that there are BHs with

at

background two questions
Background: two questions
  • What is the relation between the seed & supermassive BHs?
  • How to form supermassive BHs?
background volonteri rees 2005
108~9

103

Super Eddington

accretion

SMBH

merge

Seed

BH

Background: Volonteri & Rees (2005)

One way to form supermassive BHs:

volonteri rees 2005
Volonteri & Rees (2005)

For MBHs in halos with , the accretion radius is then well within the

disc, surrounded by gas with almost constant density , and thus a quasi-spherical

geometry

motivation can supermassive bhs form with feedback
108~9

103

Super Eddington

accretion

SMBH

merge

Seed

BH

feedback

Compton Heating

Radiation Pressure

Outflow

Motivation: Can supermassive BHs form with feedback ?

feedback

feedback limit radiation pressure
Feedback Limit: radiation pressure

The feedback from the radiation pressure is negligible

feedback limit compton heating
Feedback Limit: Compton heating

Ionization parameter:

feedback limit outflow begelman 2004
Feedback Limit : Outflow (Begelman 2004)
  • Outflow is a generic property of the accretion disk:

quasar PG 1211+143 ( Pounds et al. 2003)

some X-ray sources (Mukai et al. 2003, Fabbiano et al. 2003)

SS 433 (Kotani et al. 1996)

  • When the outflow is damped by it’s surroundings, its most kinetic energy will dissipate at sonic radius
  • For a typical outflow, the timescale reaching the sonic point is 33 yr
discussions
Discussions
  • Considering the anisotropic from the slim disk will suppress the Compton heating in some degree.
  • Some other ways to form supermassive BHs at high redshift ( )

1、Direct collapse of primordial clouds (Loeb 1993, Loeb & Rossio 1994)

2、Accretion of dark matter will not suffering from feedback (Hu et al. 2005)

3、The inevitable fate of a compact cluster is the formation of a supermassive black hole (Quinlan & Shapiro 1990)

summary
Summary

A rapid growth of the seed BH are greatly suppressed and they are hardly able to grow up unless the strong feedback can be avoided, for example considering the anisotropy of the radiation from the tiny accretion disk。

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