J/ApJS/157/59 Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)
Ultraluminous X-ray sources in nearby galaxies from ROSAT High Resolution Imager
observations.
I. Data analysis.
Liu J.-F., Bregman J.N.
<Astrophys. J. Suppl. Ser., 157, 59-125 (2005)>
=2005ApJS..157...59L 2005ApJS..157...59L
ADC_Keywords: X-ray sources ; Binaries, X-ray ; Galaxies, nearby
Keywords: catalogs - galaxies: general - X-rays: binaries - X-rays: galaxies
Abstract:
X-ray observations have revealed in other galaxies a class of
extranuclear X-ray point sources with X-ray luminosities of
1039-1041ergs/s, exceeding the Eddington luminosity for stellar
mass X-ray binaries. These ultraluminous X-ray sources (ULXs) may be
powered by intermediate-mass black holes of a few thousand MSun or
stellar mass black holes with special radiation processes. In this
paper, we present a survey of ULXs in 313 nearby galaxies with D25>1
within 40Mpc with 467 ROSAT High Resolution Imager (HRI) archival
observations. The HRI observations are reduced with uniform
procedures, refined by simulations that help define the point source
detection algorithm employed in this survey. A sample of 562
extragalactic X-ray point sources with LX=1038-1043ergs/s is
extracted from 173 survey galaxies, including 106 ULX candidates
within the D25 isophotes of 63 galaxies and 110 ULX candidates
between 1D25 and 2D25 of 64 galaxies, from which a clean sample of
109 ULXs is constructed to minimize the contamination from foreground
or background objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 312 Properties of surveyed galaxies
table2.dat 101 562 X-ray sources in surveyed galaxies
table3.dat 110 604 Individual observations for ULX candidates
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See also:
IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000)
VII/155 : RC3 (de Vaucouleurs+ 1991)
J/ApJS/154/519 : Properties of ultraluminous X-ray candidates (Swartz+, 2004)
J/A+A/429/1125 : Catalog of Ultraluminous X-ray sources (Liu+, 2005)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Galaxy Galaxy name
11- 16 F6.2 deg GLON Galactic longitude of the galaxy
18- 23 F6.2 deg GLAT Galactic latitude of the galaxy
25- 28 F4.1 arcmin D25 Major axis of the D25 isophotal ellipsis
30- 33 F4.1 arcmin d25 Minor axis of the D25 isophotal ellipsis
35- 41 E7.3 cm-2 nH Galactic HI column density (1)
43- 48 F6.3 Mpc Dist Distance
50- 52 A3 --- r_Dist Reference on Dist (2)
54- 62 A9 --- MType The RC3 morphological type (3)
64- 67 F4.1 --- HType ? The RC3 Hubble T type
69- 74 E6.2 solLum LBlue ? The Blue luminosity (4)
76 A1 --- l_F60um Limit flag on F60um
77- 85 F9.4 Jy F60um The 60µm flux density (5)
87 A1 --- l_FIRMAG Limit flag on FIRMag
88- 92 F5.1 mag FIRMAG Absolute FIR magnitude (6)
94- 98 A5 --- Flag HII/starburst galaxy high star formation rate
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Note (1): Taken from the dust map by Dickey & Lockman (1990ARA&A..28..215D 1990ARA&A..28..215D).
Note (2): Reference on Dist, defined as follows:
KP = Key Project (Freedman et al., 2001ApJ...553...47F 2001ApJ...553...47F);
SBF = Surface brightness fluctuation method (Tonry et al.,
2001ApJ...546..681T 2001ApJ...546..681T);
T92 = Nearby galaxy flow model by Tully (1992, Cat. J/ApJS/80/479);
T88 = Nearby Galaxy Catalog (Tully 1988, Cat. VII/145);
NED = Recessional velocities taken from the NED (V3K) service (RC3).
Note (3): In the type code, S stands for spiral, E for elliptical, S0 for
lenticular, I for irregular; (r) for inner ring, (s) for S-shaped,
(rs) for mixed; B for barred, A for non-barred, AB for mixed; Im
for magellanic irregular, I0 for non-magellanic irregular; the
trailing -/o/+ for early/intermediate/late stage; etc. The detailed
explanations can be found in the RC3 (Cat. VII/155) catalogue
(p. 15, Vol. I).
Note (4): Calculated from the apparent blue magnitude taken from RC3. The
luminosity is expressed in unit of solar luminosity assuming a
absolute blue magnitude of 5.47 for the Sun.
Note (5): Taken from the IRAS point source catalog (IPAC, 1986, Cat. II/125),
with some nearby galaxies from Rice et al. (1988, Cat. VII/109).
When the galaxy is below detection, the 3σ upper limit is
calculated by adopting noise levels of 8.5mJy/arcmin2 for 60µm
(Rice et al. 1988, Cat. VII/109).
Note (6): Computed from the flux densities at 60µm and 100µm as
prescribed in RC3 (Cat. VII/155). A leading "<" means the magnitude
is computed from the upper limits of the flux densities.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Galaxy Galaxy name (1)
11- 13 A3 --- XName X-ray source name (1)
15- 16 I2 h RAh Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27 A1 --- DE- Sign of the Declination (J2000)
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 37 F4.1 arcsec DEs Arcsecond of Declination (J2000)
39 I1 --- Nc Number of X-ray sources identified (2)
41- 46 F6.1 arcsec r Nuclear offset
48- 51 F4.2 --- r/R25 Nuclear offset in unit of elliptical radius R25
53- 57 F5.1 --- s-Max Maximum detection significance among observations
59- 68 F10.4 10+32W Lum Maximum luminosity among all observations (3)
70 I1 --- Nv ? Number of observations in which the probability
for the Kolmogorov-Smirnov test of the source
being constant is less than 0.01 (4)
72 A1 --- Env Environments of the X-ray source (5)
74- 89 A16 --- ID Identification of the X-ray source (6)
91- 96 A6 --- ULX Source flag (7)
98-101 A4 --- UName ULX name in the clean ULX sample
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Note (1): [LB2005] NGC NNNN XNN, [LB2005] NGC NNNNA XN, and
[LB2005] PGC NNNNN XNN in Simbad.
Note (2): With objects in astrometric catalogs used to correct the
X-ray positions.
Note (3): The X-ray luminosities are computed using a power-law spectrum
between 0.3-8keV with a photon index of 1.7.
Note (4): i.e., the source is highly variable during the observation.
Note (5): Environments of the X-ray source, defined as follows:
D = the source is in a dusty region usually associative of
star forming activities.
S = the source is associated with spiral arms.
Note (6): Identification of the X-ray source, with symbols:
* = the source is a bright foreground star;
P/(Pr) = the source is positionally coincident with a point source
in optical/IR/(Radio);
mP = the source is close to multiple such point sources and unique
identification requires better positions;
Z = the source is close to faint fuzzy features on the optical image.
() = Identification enclosed with parentheses when it is within the
host galaxy.
Note (7): This indicates whether the source is a nuclear source (N) or a
ULX candidate (ULX). Prefix '1' stands for ULXs within the D25
isophote of the galaxy, '2' for ULXs between 1D25 and 2D25, and
'E' for ULXs with LX>1040erg/s. Suffix 'd' stands for ULXs that
are above 1039erg/s in the deepest observation for the galaxy.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Galaxy Galaxy name (1)
11- 14 A4 --- Name Source name (1) (2)
16- 30 A15 --- Obs Individual observation (3)
32- 36 I5 d MJD Observation date in MJD (JD-2400000.5)
38- 42 F5.1 ks ExpTime Exposure time
44- 47 F4.1 --- DelD Time duration of the observation
48 A1 --- x_DelD [dh] Units for DelD value: days (d), hours (h)
50 A1 --- l_sigma Limit flag on sigma
51- 55 F5.1 --- sigma Detection significance
57- 61 F5.2 arcmin theta ? Off-axis angle
63- 66 F4.2 --- C ? Correction factor based on the simulations
68 A1 --- l_CorCnt Limit flag on CorCnt
69- 74 F6.1 ct CorCnt X-ray source count corrected by applying C
76- 80 F5.2 % e_CorCnt ? Fractional error for the corrected count
82 A1 --- l_Flux Limit flag on Flux
83- 90 E8.3 mW/m2 Flux Flux in units of erg/s/cm2 (4)
92 A1 --- l_LX Limit flag on LX
93-101 F9.4 10+32W LX ? X-ray luminosity in units of 10+39erg/s (5)
104-110 E7.2 --- PKS ? Non-variability test probability (6)
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Note (1): [LB2005] NGC NNNN ULXN, [LB2005] NGC NNNNA ULXN,
[LB2005] PGC NNNNN ULXN, in Simbad.
Note (2): The source name refers to UName (table2.dat) if it starts with 'ULX',
to XName (table2.dat) otherwise.
Note (3): Suffixed is the sequence number in the source list from wavdetect.
'U' is suffixed when the source is below 3σ detection in the
observation. '+' is suffixed if the observation has the deepest
sensitivity for the host galaxy.
Note (4): Computed with the corrected source count, by assuming a power-law
spectrum between 0.3-8keV with a photon index of 1.7.
Note (5): Computed from the flux by assuming a distance to the host galaxy.
Note (6): The probability for the Kolmogorov-Smirnov test null hypothesis
that the source is constant during the observation.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 04-Aug-2005