J/ApJ/829/20 Chandra ACIS survey in nearby galaxies. II (Wang+, 2016)
Chandra ACIS Survey of X-Ray Point Sources in Nearby Galaxies. II. X-Ray
Luminosity Functions and Ultraluminous X-Ray Sources.
Wang S., Qiu Y., Liu J., Bregman J.N.
<Astrophys. J., 829, 20 (2016)>
=2016ApJ...829...20W 2016ApJ...829...20W
ADC_Keywords: X-ray sources ; Galaxies, nearby ; Surveys
Keywords: catalogs ; galaxies: general ; X-rays: binaries ; X-rays: galaxies
Abstract:
Based on the recently completed Chandra/ACIS survey of X-ray point
sources in nearby galaxies, we study the X-ray luminosity functions
(XLFs) for X-ray point sources in different types of galaxies and the
statistical properties of ultraluminous X-ray sources (ULXs). Uniform
procedures are developed to compute the detection threshold, to
estimate the foreground/background contamination, and to calculate the
XLFs for individual galaxies and groups of galaxies, resulting in an
XLF library of 343 galaxies of different types. With the large number
of surveyed galaxies, we have studied the XLFs and ULX properties
across different host galaxy types, and confirm with good statistics
that the XLF slope flattens from lenticular
(α∼1.50±0.07) to elliptical (∼1.21±0.02), to
spirals (∼0.80±0.02), to peculiars (∼0.55±0.30), and
to irregulars (∼0.26±0.10). The XLF break dividing the
neutron star and black hole binaries is also confirmed, albeit at
quite different break luminosities for different types of galaxies. A
radial dependency is found for ellipticals, with a flatter XLF slope
for sources located between D25 and 2D25, suggesting the XLF
slopes in the outer region of early-type galaxies are dominated by
low-mass X-ray binaries in globular clusters. This study shows that
the ULX rate in early-type galaxies is 0.24±0.05 ULXs per surveyed
galaxy, on a 5σ confidence level. The XLF for ULXs in late-type
galaxies extends smoothly until it drops abruptly around
4x1040erg/s, and this break may suggest a mild boundary between the
stellar black hole population possibly including 30M☉ black holes
with super-Eddington radiation and intermediate mass black holes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 343 X-Ray point source populations in 343 nearby galaxies
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See also:
IX/45 : The Chandra Source Catalog, Release 1.1 (Evans+ 2012)
VII/109 : IRAS Observations of Large Optical Galaxies (Rice+, 1988)
J/MNRAS/419/2095 : HMXBs in nearby galaxies (Mineo+, 2012)
J/ApJ/741/49 : ULX candidates in nearby galaxies (Swartz+, 2011)
J/ApJS/192/10 : Chandra ACIS survey in 383 nearby galaxies. I. (Liu, 2011)
J/ApJ/689/983 : LMXBs in early-type galaxies. I. Chandra (Humphrey+, 2008)
J/ApJ/681/1163 : Late-type galaxies in Chandra deep fields (Lehmer+, 2008)
J/ApJ/662/525 : LMXBs in globular clusters of 5 galaxies (Kundu+, 2007)
J/A+A/429/1125 : Catalog of Ultraluminous X-ray sources (Liu+, 2005)
J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)
J/ApJ/602/231 : Chandra X-ray point sources in nearby galaxies
(Colbert+, 2004)
J/AJ/124/2351 : Chandra Deep Field North survey. XII (Bauer+, 2002)
J/MNRAS/330/547 : Local galaxy ages and metallicities (Terlevich+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Galaxy Galaxy name
10- 11 I2 --- Nobs [1/28] Number of observations (1)
13- 15 I3 --- Nsrc [0/434] Number of X-ray point sources (2)
17- 19 I3 --- NXt [0/292] Number of sources detected (3)
21- 24 F4.2 --- fCov [0.31/1] Sky coverage (4)
26- 30 F5.2 [10-7W] LXlim [35.38/39.83] Limiting X-ray luminosity (5)
32- 34 I3 --- NX [0/255] Number of sources detected above
LXlim
36- 41 F6.2 --- Nb/f [0/237.18] Predicted foreground/background
sources for L>LXlim
43- 44 I2 --- NUa [0/16] Number of ULXs found in all
observations
46- 50 F5.2 --- nU [-1.72/8.93] Net number of ULXs from this
stitched survey (6)
52- 55 F4.2 --- nb/f [0/1.72] Predicted foreground/background
sources for L>2.1039erg/s
57- 66 A10 --- GType Galaxy type
68- 74 E7.2 Lsun LB Blue light content of the galaxy
76- 82 F7.2 arcmin2 GArea [0.29/2318.71] D25 isophotal area
84- 90 F7.4 Mpc Dist [0.8166/49.5] Galaxy distance
92 A1 --- l_SFR60um [<] Limit flag on SFR60um
93-100 F8.5 Msun/yr SFR60um [0.00034/55.4]? Star formation rate (7)
102-112 A11 --- Activity Star-forming and nuclear activities
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Note (1): Number of ACIS observations utilized in Liu et al. (2011,
Cat. J/ApJS/192/10)
Note (2): Number of X-ray point sources detected above 4σ in all
observations.
Note (3): Number of sources detected above 4σ in the stitched deep survey.
Note (4): Surveyed area A as a fraction of the D25 isophotal area.
Note (5): Limiting X-ray luminosity at which the surveyed blue light is 50% of
the total blue light surveyed.
Note (6): Number of ULXs detected in the deep survey minus the predicted
foreground/background sources for L>2.1039erg/s.
Note (7): Star formation rate estimated based on the flux density at 60µm
observed by IRAS.
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History:
From electronic version of the journal
References:
Liu et al. Paper I 2011ApJS..192...10L 2011ApJS..192...10L
(End) Marianne Brouty [CDS] 06-Mar-2018