Accretion in Early-Type Galaxies

Haiguang XuDepartment of Physics

Shanghai Jiao Tong Universityhgxu@sjtu.edu.cn

Acrretion from the ambient cosmological flow – origin of the ISM – gas heating

Accretion by a central massive black hole – central engine of an AGN – jet and heating of the ISM

Accretion by an intermediately massive black hole in globular clusters – intermediate mass black holes – ULXs – formation and evolution of AGNs

1 Central SourceHost galaxies of the radio–loud quasars and radio galaxies appear to be giant elliptical galaxies Existence of central massive black holes e.g., a few 107 M in N4472, 108–9 M in quasars (Wu et al. 2003) The continuing accretion of the hot gas from the extensive halo should make these galaxies more luminous than they appear if the radiative efficiency is 10% (e.g., Fabian & Canizares 1988)

Bondi Accretion:

> 1043 erg s–1 in most giant ellipticals (e.g., Fabbiano 1989)

Total X-ray luminosity in E galaxies: 1036–43 erg s–1, diffuse & point sources

the problem of starving the monster Lower accretion rate? Lower radiative efficiency? Fabian & Rees 1995

Possible solutions (e.g., Fabian & Canizares 1988, Nature 333, 829)

Emissions in unobservable bands Kinetic energy in the jet Outflows or relativistic gas surrounding the BH that preventing accretion Angular momentum that preventing the gas from reaching the BH Time dependnce Low efficiency Most bright elliptical galaxies do not contain massive black holes

NGC 6166 (Abell 2199) Di Matteo et al. 2001

Central black hole: 109 M

Bondi rate: < 310–2 M yr–1

about 10 times lower than the ROSAT HRI values for e.g., M87, NGC 4649 & NGC 4472 (Di Matteo et al. 2000), but more consistent with high frequencyradio measurements (Di Matteo et al. 1999, 2000; Wrobel & Herrnstein 2000)

A nuclear luminosity of 1044 erg s–1 in X-rays if the radiative efficiency is 10%, which is 4 orders of magnitudes larger than the Chandra measurement in 0.5–7 keV (41040 erg s–1 )

= 10–5 pure inflow ADAF models are preferred (e.g., Rees et al. 1982)

However, the Bondi accretion rate may have been overestimated, and the requirement for low radiative efficiency may be relaxed, because Gas density and temperature are measured at about 1 kpc (15 RA) If strong convection develops, as in CDAFs, accretion rate could be reduced Heating of the ISM by the jets could decrease the Bondi accretion radius

M87 (Virgo)Di Matteo et al. 2003Spatial resolution of Chandra: < 100 pc (a few 105 Schwarzschild radii)

Central black hole: 3109 M (e.g., Ford et al. 1995; Harms et al. 1995)

Bondi rate: 0.1 M yr–1 LBondi = 51044 erg s–1 with = 0.1

L0.5-7 keV = 71040 erg s–1 Multiwavelength spectrum of the nucleus is consistent with the prediction of a advection dominated flow The flow shall be modified by the existence of jet and/or outflowMost of the accretion energy is released in the relativistic jet that may reducethe accretion rate. The central engine may undergoes on-off activity circles

Chandra 0.5-5 keV

NGC 1399, NGC 4472, NGC 4636 Loewenstein et al. 2001

NGC 4636

For 108–9 black holes, the observed upper limits of the luminosity are7.310–9 LEdd (NGC 1399) 1510–9 LEdd (NGC 4472)2810–9 LEdd (NGC4636) so that the corresponding radiative efficiencies of Bondi accretion are extremely low4.110–6 (NGC 1399) 2410–6 (NGC 4472)62010–6 (NGC4636)These are inconsistent with the standard advection-dominated accretion flowmodels for NGC 1399 and NGC 4472 Accretion rates at lower than 10% of the Bondi rate

Faint soft central sources in NGC 4472 & NGC 4649 (Soldatenkov et al. 2003)Detectedable below 0.6 keV, heavily absorbed 0.2–2.5 keV luminosity: 1.71038 erg s–1 for NGC 4472 6 1037 erg s–1 for NGC 4649

2 Black Holes in Globular ClustersA tight correlation between the mass of a galaxy’s central black hole and the luminosity-weighted line-of-sight velocity dispersion within the half-light radius for 26 galaxies (Gebhardt et al. 2000) The formation process of both bulges and massive clusters is similar

(Gebhardt et al. 2000)

Gas KinematicsStellar KinematicsMaser Dtections

A 2.0(+1.4, –0.8)104 M Black Hole in G1 (M31)Gebhardt et al. 2002

A 3.9(±2.2103) M

Black Hole in M15Gerssen et al. 2002

But see Naccarone et al. 2005: uppers limit of about 100 Jy at GHz frequencies

< 100 M with Bondi-Hoyle rate with an upper limit of about 1000 M if more realistic assumptions are made by using a larger accretion rate

G1 (M31)

Gebhardt et al. 2002

Zheng 2001

Chandra Study of NGC 4552

47 LMXBs

25 LMXBs and 210 GCs

In the 4 Re region of NGC 4552 47 X-ray point sources; central source: 41039 erg s–1

not very soft, no excess absorption of the 46 off-center sources, 3 have luminosities > 1039 erg s-1

1 is associated with a GC and has M=15–135 M

Chandra Study of NGC 1407

X-ray point sources with LX > 1039 erg s-1 in NGC 1407

13910 sergLX

kTin (keV) LX (1039 erg s–1 ) Mass (MSun)

(Schwarzschild)

Mass (MSun)

(Kerr)

0.37 1.08 89 60-536

0.68 1.75 34 22-202

1.27 2.01 10 6.7-60

0.49 3.69 94 63-566

1.06 1.92 15 10-87

2.17 2.08 3.6 2.4-22

A Radio Test of the Existence of Intermediate MassBlack Holes in Globular Clusters and Dwarf Spheroidal GalaxiesMaccarone 2004

ULXs and Formation of IMBHs1) The accreting black holes have ordinary stellar mass whose emission is beamed (King et al. 2001) 2) These black holes formed directly via evolution of Popular III stars (Madau & Rees 2001)3) These black holes grow by accretion (Miller & Hamilton 2002)

The Accretion Scenario A black hole with < 103 M accreting from the ISM too slow

A 10 M black hole sinks to the cluster core within 107 yr to form a binary,which is tightened by 3-body interactions that cause recoil kickout(Sigurdsson & Hernquist 1993)

Growth from a > 50 M black hole in 1010 yr

Kawakatu & Umemura 2005

3 X-Ray Luminosity Function of Point Sources

NGC 4697Sarazin et al. 2000A knee on the XLF around theEddington Luminosity of normalaccreting neutron stars with a mass of 1.4 M, LEdd = 21038 erg s–1

Also in NGC 1553 (Blanton et al. 2001)NGC 4472 (Kundu et al. 2002)

However, for a sample of 14 E/S0 galaxies, Kim and Fabbiano (2004) found the break is higher.

NGC 720 (Jeltema et al. 2003), NGC 4365, NGC 4382 (Sivakoff et al. 2003)M87, M49, M4697 (Jordan et al. 2004): a break/cutoff at > 1039 erg s–1

NGC 1600 (Sivakoff et al. 2004): no break

The Cumulative X-Ray Luminosity Function of NGC 1407Zhang et al. 2005 A broken power-law profile with Lb=4.41038 erg s-1

No obvious difference between the luminosity distributions of GC LMXBs and field LMXBs.