Feedback Limits Rapid Growth Seed BHs at High Redshift Jianmin Wang, Yanmei Chen, Chen Hu Institute of High Energy Physics

Outline Background and Motivation Background and Motivation Growth: Feedback Limit Growth: Feedback Limit Radiation pressure Radiation pressure Compton heating Compton heating Outflow Outflow Discussion Discussion Conclusion Conclusion

Background: observations Early reionization epoch needs a large population of BHs Early reionization epoch needs a large population of BHs SDSS indicates that there are BHs with SDSS indicates that there are BHs with at at

Background: two questions What is the relation between the seed & supermassive BHs? What is the relation between the seed & supermassive BHs? How to form supermassive BHs? How to form supermassive BHs?

Background: Rees diagram

Background: Volonteri & Rees (2005) One way to form supermassive BHs: ~9 Seed BH Super Eddington accretion merge SMBH

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

Background: Volonteri & Rees (2005)

Motivation: Can supermassive BHs form with feedback ? Radiation Pressure Outflow feedback Compton Heating feedback ~9 Seed BH Super Eddington accretion merge SMBH

The feedback from the radiation pressure is negligible Feedback Limit: radiation pressure

Feedback Limit: Compton heating Ionization parameter:

Feedback Limit: Compton heating

Feedback Limit : Outflow (Begelman 2004) Outflow is a generic property of the accretion disk: Outflow is a generic property of the accretion disk: quasar PG ( Pounds et al. 2003) quasar PG ( Pounds et al. 2003) some X-ray sources (Mukai et al. 2003, Fabbiano et al. 2003) some X-ray sources (Mukai et al. 2003, Fabbiano et al. 2003) SS 433 (Kotani et al. 1996) SS 433 (Kotani et al. 1996) When the outflow is damped by it s surroundings, its most kinetic energy will dissipate at sonic radius 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 For a typical outflow, the timescale reaching the sonic point is 33 yr

Discussions Considering the anisotropic from the slim disk will suppress the Compton heating in some degree. 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 ( ) Some other ways to form supermassive BHs at high redshift ( ) 1 Direct collapse of primordial clouds (Loeb 1993, Loeb & Rossio 1994) 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) 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) 3 The inevitable fate of a compact cluster is the formation of a supermassive black hole (Quinlan & Shapiro 1990)

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 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