Black Holes Accretion vs Galaxy Properties
description
Transcript of Black Holes Accretion vs Galaxy Properties
Max-Planck-Institut für extraterrestrische Physik,
Garching, GERMANY
Angela BongiornoAngela Bongiorno
Cols: A. Merloni, G. Zamorani, M. Brusa, D. Vergani et al.
Honolulu, June 9th 2010
Hie
rarc
hica
l gr
owth
Grow
th of SM
BH
Gas inflow
AGN feedback Active
Quasar
Starburst &buried Quasar
Normal galaxies
Galaxy mergers
(adapted from Hopkins et al., 2008)
EVOLUTIONARY SCENARIO
Fraction of Obscured AGN vs L and z
0.15< z <0.3 from ∼65% to ∼50% from L[O III]=106.2 -108.2 L to 108.2-109.2L
• at L[OIII] > Lc, decreasing fraction of type–2 AGN with luminosity
• What happen at L[OIII] < Lc?
0.3< z <0.45 and 0.5< z <0.92 from ∼80% to ∼25% from L[O III =106.2-108.5L ⊙ to L[O III]=109.0-109.6L ⊙
(Bongiorno, Mignoli, Zamorani et al., 2010 A&A 510, 56B)
SDSS (Reyes08)zCOSMOS
0.15<z<0.3 0.3<z<0.45 0.5<z<0.9
SDSS type-2 AGN sample @z<0.3 (Kauffmann & Heckman 2008)
BH accretion as a function of galaxy properties…
Feast: Galaxies rich in cold gas ; BH growth is regulated by small-scale feedback.
Famine: Galaxies poor in cold gas. BH accretes ~0.3% - 1% of the mass lost by evolved bulge stars.
~2% Edd
Eddington Log(L[OIII]/MBH) =1.7
BH accretion and star formation…at higher redshift
using the 20k zCOSMOS type-2 AGN sample 392 sources @ z~1
(close to the peak of the cosmic AGN and star formation density)➤ AGN hosts masses through SED fitting
• AGN templates: - Elvis et al. (1994) - E(b-v)=0 - 0.3 in 0.01 steps• Galaxy templates: - 14 phenomenological from Polletta (2007) - Libr. of synthetic sp. (Bruzual & Charlot) a) 10 declining SFH SFR e-t/ =[0.1-30] Gyr tage=[50Myr-5 Gyr] tage<tuniv(z) 0 < E(B-V) <0.5 b) 1 constant SF
Separate the Spectral Energy Distribution of AGN into nuclear+host components and derive the host properties
(Merloni, Bongiorno et al. 2010 ApJ 708, 137M)
Red/Purple: Galaxy templateBlue: AGN template
Used Bands6 SUBARU bands
K band (CFHT)4 Spitzer/IRAC
24m Spitzer/MIPS
SED fitting M* (scaling relation) BH masses
(150)
~1.5%Edd~0.2%Edd
( Bongiorno, Merloni et al. in prep)
BH accretion and star formation…at higher redshift
➤ Computation of the BH Masses
( Bongiorno, Merloni et al. in prep)
Using the sSFR to distinguish “old” and “young” galaxies
~0.6%Edd~0.02%Edd
(391)
( Bongiorno, Merloni et al. in prep)
Using the sSFR to distinguish “old” and “young” galaxies
Dotted lines: [OIII] completeness limit
Gradual trend towards lower Eddington ratios with older stellar population content.
However … selection effect still to be fully accounted for…