J/ApJ/714/25 AMUSE-Virgo survey. II. (Gallo+, 2010)
AMUSE-virgo.
II. Down-sizing in black hole accretion.
Gallo E., Treu T., Marshall P.J., Woo J.-H., Leipski C., Antonucci R.
<Astrophys. J., 714, 25-36 (2010)>
=2010ApJ...714...25G 2010ApJ...714...25G
ADC_Keywords: X-ray sources ; Clusters, galaxy ; Galaxies, nearby ; Surveys ;
Velocity dispersion
Keywords: black hole physics - galaxies: clusters: individual (Virgo)
Abstract:
We complete the census of nuclear X-ray activity in 100 early-type
Virgo galaxies observed by the Chandra X-ray Telescope as part of the
AMUSE-Virgo survey, down to a (3σ) limiting luminosity of
3.7x1038erg/s over 0.5-7keV. The stellar mass distribution of the
targeted sample, which is mostly composed of formally "inactive"
galaxies, peaks below 1010M☉, a regime where the very
existence of nuclear supermassive black holes (SMBHs) is debated. Out
of 100 objects, 32 show a nuclear X-ray source, including 6 hybrid
nuclei which also host a massive nuclear cluster as visible from
archival Hubble Space Telescope images. After carefully accounting for
contamination from nuclear low-mass X-ray binaries based on the shape
and normalization of their X-ray luminosity function (XLF), we
conclude that between 24% and 34% of the galaxies in our sample host
an X-ray active SMBH (at the 95% confidence level). This sets a firm
lower limit to the black hole (BH) occupation fraction in nearby
bulges within a cluster environment.
Description:
In Cycle 8 we proposed and were awarded a large Chandra/Spitzer
program to observe 100 (84 new + 16 archival) spheroidal galaxies in
the Virgo Cluster (AMUSE-Virgo; PI: Treu, 454ks). The targeted sample
is that of the Hubble Virgo Cluster Survey (VCS; Cote et al. 2004,
Cat. J/ApJS/153/223). For each galaxy, the high-resolution g- and
z-band images enable us to resolve, when present, the nuclear star
cluster, infer its enclosed mass, and thus estimate the chance
contamination from a low-mass X-ray binary (LMXB) as bright/brighter
than the detected X-ray core based on the shape and normalization of
the LMXB luminosity function in external galaxies. As a part of the
AMUSE-Virgo survey, each VCS galaxy was observed with Chandra/ACIS for
a minimum of 5.4ks. The Chandra results from the first 32 targets (16
new + 16, typically more massive, archival observations) have been
presented by Gallo et al. (Paper I; 2008ApJ...680..154G 2008ApJ...680..154G). In Paper II,
we complete the X-ray analysis of the whole AMUSE-Virgo sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 59 100 AMUSE-Virgo. II. Nuclear properties
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See also:
J/ApJS/164/334 : ACS Virgo Cluster Survey. VI (Ferrarese+, 2006)
J/ApJ/600/729 : Chandra LMXB in NGC 4649 (Randall+, 2004)
J/ApJS/153/223 : ACS Virgo Cluster Survey. I. (Cote+, 2004)
J/ApJ/599/218 : Chandra LMXB in NGC 4365 and NGC 4382 (Sivakoff+, 2003)
J/ApJ/586/814 : NGC 4472 Chandra/HST study (Maccarone+, 2003)
J/A+AS/142/65 : Galaxies morphology and IR photometry III. (Gavazzi+, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ACSVCS ACS Virgo Cluster Survey target number
5- 8 I4 --- VCC VCC source name (Cat. J/AJ/90/1681)
10- 18 A9 --- OName Other designation(s) (N=NGC, I=IC)
20- 24 F5.2 Mpc Dist Distance (1)
26- 30 F5.2 mag Bmag Extinction corrected B-band magnitude (2)
32- 34 I3 km/s sigma ? Velocity dispersion
36- 37 I2 km/s e_sigma ? Sigma uncertainty
39 I1 --- r_sigma [1/2]? Sigma reference when not from ENEARc (3)
41- 43 F3.1 [Msun] logMBH Log of black hole mass (4)
45 A1 --- l_logLx Limit flag on logLx
46- 50 F5.2 [10-7W] logLx Nuclear luminosity between 0.3 and 10keV,
corrected for absorption
52- 54 A3 --- r_logLx Reference(s) (from Paper I) for logLx (5)
56- 59 F4.1 [Msun] logM* Log of stellar mass of the host galaxy (6)
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Note (1): Distance (from the surface brightness fluctuations method; Mei et al.
2007ApJ...655..144M 2007ApJ...655..144M; see also Blakeslee et al. 2009ApJ...694..556B 2009ApJ...694..556B).
The average distance to the Virgo Cluster (of 16.5Mpc) is employed in
the case of no available distance modulus.
Note (2): Extinction-corrected B magnitude, estimated as described in Paper I
(Gallo et al. 2008ApJ...680..154G 2008ApJ...680..154G); E(B-V) values are from Ferrarese
et al. (2006, Cat. J/ApJS/164/334).
Note (3): Stellar velocity dispersion, from ENEARc (Bernardi et al.
2002AJ....123.2990B 2002AJ....123.2990B), unless otherwise indicated as follows:
1 = Gavazzi et al. (2000, Cat. J/A+AS/142/65)
2 = Davies et al. (1987ApJS...64..581D 1987ApJS...64..581D)
Note (4): BH mass, estimated according to the "fiducial distribution" described
in Section 4 of Paper I (Gallo et al. 2008ApJ...680..154G 2008ApJ...680..154G).
Note (5): Reference (from Paper I; Gallo et al. 2008ApJ...680..154G 2008ApJ...680..154G) as
follows:
3 = Biller et al. 2004ApJ...613..238B 2004ApJ...613..238B
4 = Soldatenkov et al. 2003AstL...29..298S 2003AstL...29..298S
5 = Di Matteo et al. 2003ApJ...582..133D 2003ApJ...582..133D
6 = Wilson & Yang 2002ApJ...568..133W 2002ApJ...568..133W
7 = Randall et al. 2004, Cat. J/ApJ/600/729, report on a point-like X-ray
source at 1.6" from the nucleus. After cross-matching the Chandra
astrometry to SDSS, the position of the nuclear X-ray source is found to
be consistent with the galaxy nucleus.
8 = Sivakoff et al. 2003, Cat. J/ApJ/599/218
9 = Finoguenov & Jones 2001ApJ...547L.107F 2001ApJ...547L.107F
10 = Xu et al. 2005ApJ...631..809X 2005ApJ...631..809X
11 = Satyapal et al. 2005ApJ...633...86S 2005ApJ...633...86S
12 = Dudik et al. 2005ApJ...620..113D 2005ApJ...620..113D
13 = Soria et al. 2006ApJ...640..143S 2006ApJ...640..143S, 2006ApJ...640..126S 2006ApJ...640..126S; the nuclear X-ray
source in VCC 1297 has a soft spectrum. However, a thermal model provides
a statistically worse fit that a power law model (employing Cash
statistics), implying that most of the X-ray emission is likely
accretion-powered.
14 = The X-ray source appears slightly elongated; LX,nucl is estimated
within the Chandra PSF at 1.5keV.
Note (6): Stellar mass of the host galaxy derived from g0 and z0 band AB
model magnitudes following Bell et al. (2003ApJS..149..289B 2003ApJS..149..289B), as
described in Paper I (Gallo et al. 2008ApJ...680..154G 2008ApJ...680..154G; eq. (3)):
log(M*/Lg0)=0.698(g0-z0)-0.367
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History:
From electronic version of the journal
References:
Gallo et al. Paper I. 2008ApJ...680..154G 2008ApJ...680..154G
Leipski et al. Paper III. 2012ApJ...744..152L 2012ApJ...744..152L
(End) Emmanuelle Perret [CDS] 16-Apr-2012