Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2012-01-05
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
14 pages, 6 figures, submitted to MNRAS
Scientific paper
We develop a radiation pressure-balanced model for the interstellar medium of high-redshift galaxies that describes many facets of galaxy formation at z>~6, including star formation rates and distributions and gas accretion onto central black holes. We first show that the vertical gravitational force in the disk of such a model is dominated by the disk self-gravity but that both radiation pressure on dust grains and turbulent pressure from dense clumps and disk instabilities are negligible compared with the radiation pressure of starlight on gas. Constraining our model to reproduce the UV luminosity function of Lyman-break galaxies (LBGs), we limit the available parameter-space to wind mass-loading factors 1--4 times the canonical value for momentum-driven winds. We then focus our study by exploring the effects of different angular momentum transport mechanisms in the galactic disk and find that viscosity driven by gravitational torques, such as from linear spiral waves or non-linear orbit crossings, can build up black hole masses by z=6 consistent with canonical M-sigma relations with a duty cycle of unity, while infall mediated by a local viscosity such as in an alpha-disk results in negligible BH accretion. Both gravitational torque models produce X-ray emission from active galactic nuclei in high redshift LBGs in excess of the estimated contribution from high-mass X-ray binaries and consistent with a recent analysis of deep Chandra observations by Cowie et al. We find that future observations with larger sample sizes may be able to distinguish between these different angular momentum transport mechanisms.
Furlanetto Steven R.
Muñoz Joseph A.
No associations
LandOfFree
Faint AGN in z>~6 Lyman-break Galaxies Powered by Cold Accretion and Rapid Angular Momentum Transport does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Faint AGN in z>~6 Lyman-break Galaxies Powered by Cold Accretion and Rapid Angular Momentum Transport, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Faint AGN in z>~6 Lyman-break Galaxies Powered by Cold Accretion and Rapid Angular Momentum Transport will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-661204