scholarly journals Probing black hole accretion in quasar pairs at high redshift

2018 ◽  
Vol 477 (1) ◽  
pp. 780-790 ◽  
Author(s):  
C Vignali ◽  
E Piconcelli ◽  
M Perna ◽  
J Hennawi ◽  
R Gilli ◽  
...  
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Black Hole Accretion ◽  
Hole Accretion

scholarly journals The deepest X-ray view of high-redshift galaxies: constraints on low-rate black hole accretion

2016 ◽  
Vol 463 (1) ◽  
pp. 348-374 ◽  
Author(s):  
F. Vito ◽  
R. Gilli ◽  
C. Vignali ◽  
W.N. Brandt ◽  
A. Comastri ◽  
...  
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
High Redshift Galaxies ◽  
X Ray ◽  
Black Hole Accretion ◽  
Hole Accretion ◽  
Low Rate ◽  
Redshift Galaxies

scholarly journals Reionization with galaxies and active galactic nuclei

2020 ◽  
Vol 495 (3) ◽  
pp. 3065-3078 ◽  
Author(s):  
Pratika Dayal ◽  
Marta Volonteri ◽  
Tirthankar Roy Choudhury ◽  
Raffaella Schneider ◽  
Maxime Trebitsch ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Star Formation ◽  
High Redshift ◽  
Mass Function ◽  
Stellar Mass ◽  
Relative Role ◽  
Black Hole Accretion ◽  
Wide Range ◽  
Hole Accretion

ABSTRACT In this work we investigate the properties of the sources that reionized the intergalactic medium (IGM) in the high-redshift Universe. Using a semi-analytical model aimed at reproducing galaxies and black holes in the first ∼1.5 Gyr of the Universe, we revisit the relative role of star formation and black hole accretion in producing ionizing photons that can escape into the IGM. Both star formation and black hole accretion are regulated by supernova feedback, resulting in black hole accretion being stunted in low-mass haloes. We explore a wide range of combinations for the escape fraction of ionizing photons (redshift-dependent, constant, and scaling with stellar mass) from both star formation ($\langle f_{\rm esc}^{\rm sf} \rangle$) and AGN ($f_{\rm esc}^{\rm bh}$) to find: (i) the ionizing budget is dominated by stellar radiation from low stellar mass ($M_*\lt 10^9 \, {\rm \rm M_\odot }$) galaxies at z > 6 with the AGN contribution (driven by $M_{bh}\gt 10^6 \, {\rm \rm M_\odot }$ black holes in $M_* \gtrsim 10^9\, {\rm \rm M_\odot }$ galaxies) dominating at lower redshifts; (ii) AGN only contribute $10-25{{\ \rm per\ cent}}$ to the cumulative ionizing emissivity by z = 4 for the models that match the observed reionization constraints; (iii) if the stellar mass dependence of $\langle f_{\rm esc}^{\rm sf} \rangle$ is shallower than $f_{\rm esc}^{\rm bh}$, at z < 7 a transition stellar mass exists above which AGN dominate the escaping ionizing photon production rate; (iv) the transition stellar mass decreases with decreasing redshift. While AGN dominate the escaping emissivity above the knee of the stellar mass function at z ∼ 6.8, they take-over at stellar masses that are a tenth of the knee mass by z = 4.

Iron Fluorescence from within the Innermost Stable Orbit of Black Hole Accretion Disks

1997 ◽  
Vol 488 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Christopher S. Reynolds ◽  
Mitchell C. Begelman
Keyword(s):  
Black Hole ◽  
Accretion Disks ◽  
Stable Orbit ◽  
Black Hole Accretion ◽  
Hole Accretion

Hydrodynamics of Black Hole–Accretion Disk Collision

1998 ◽  
Vol 507 (1) ◽  
pp. 131-144 ◽  
Author(s):  
Pavel B. Ivanov ◽  
Igor V. Igumenshchev ◽  
Igor D. Novikov
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Black Hole Accretion ◽  
Black Hole Accretion Disk ◽  
Hole Accretion

The magnetohydrodynamics of black hole accretion

1986 ◽  
Vol 126 (1) ◽  
pp. 99-104 ◽  
Author(s):  
U. S. Pandey ◽  
G. S. Dubey
Keyword(s):  
Black Hole ◽  
Black Hole Accretion ◽  
Hole Accretion

scholarly journals The Galaxy Zoo survey for giant AGN-ionized clouds: past and present black hole accretion events

2011 ◽  
Vol 420 (1) ◽  
pp. 878-900 ◽  
Author(s):  
William C. Keel ◽  
S. Drew Chojnowski ◽  
Vardha N. Bennert ◽  
Kevin Schawinski ◽  
Chris J. Lintott ◽  
...  
Keyword(s):  
Black Hole ◽  
Black Hole Accretion ◽  
The Galaxy ◽  
Hole Accretion
Sign in / Sign up

Export Citation Format

Share Document