J/MNRAS/281/799 XBACs, the sample (Ebeling+, 1996)
Properties of the X-ray-brightest Abell-type clusters of galaxies (XBACs)
from ROSAT All-Sky Survey Data - I. The sample.
Ebeling H., Voges W., Bohringer H., Edge A.C., Huchra J.P., Briel U.G.
<Mon. Not. R. Astron. Soc. 281, 799 + Erratum vol. 283, p. 1103 (1996)>
=1996MNRAS.281..799E 1996MNRAS.281..799E
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Redshifts
Keywords: surveys, galaxies: clusters: general, cosmology: observations,
large-scale structure of Universe, X-rays: galaxies
Abstract:
We present an essentially complete, all-sky, X-ray flux-limited sample
of 242 Abell clusters of galaxies (six of which are double) compiled
from ROSAT All-Sky Survey data. Our sample is uncontaminated in the
sense that systems featuring prominent X-ray point sources such as AGN
or foreground stars have been removed. The sample is limited to high
Galactic latitudes (|b|≥20°), the nominal redshift range of the
ACO catalogue of z≤0.2, and X-ray fluxes above 5.0x10-12erg/cm2/s
in the 0.1-2.4keV band. Owing to the X-ray flux limit, our sample
consists, at intermediate and high redshifts, exclusively of very
X-ray-luminous clusters. Since the latter tend to be also optically
rich, the sample is not affected by the optical selection effects and,
in particular, not by the volume incompleteness known to be present in
the Abell and ACO catalogues for richness class 0 and 1 clusters. Our
sample is the largest X-ray flux-limited sample of galaxy clusters
compiled to date and will allow investigations of unprecedented
statistical quality into the properties and distribution of rich
clusters in the local Universe.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 142 37 *Excluded sources
table34.dat 124 283 The sample of the 283 X-ray-brightest Abell-type
clusters
refs.dat 167 48 Redshift references
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Note on table2.dat: Sources with VTP count rates (Voronoi tesselation
and percolation method) higher than 0.25s-1 that were excluded
as being dominated by, if not entirely due to, X-ray emission of
non-cluster origin
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See also:
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
J/MNRAS/301/881 : The ROSAT brightest cluster sample - I. (Ebeling+, 1998)
J/MNRAS/306/857 : ROSAT Brightest Cluster Sample. III. (Crawford+, 1999)
J/MNRAS/318/333 : Extended ROSAT Bright Cluster Sample (Ebeling+ 2000)
J/ApJ/502/558 : Catalog of ROSAT galaxy clusters (Vikhlinin+ 1998)
J/ApJ/514/148 : ROSAT survey of bright galaxies clusters (De Grandi+, 1999)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- --- [A]
2- 5 I4 --- ACO Abell Cluster number (Cat. VII/110)
7- 8 I2 h RAh Right ascension (B1950)
9- 10 I2 min RAm Right ascension (B1950)
11- 14 F4.1 s RAs Right ascension (B1950)
15 A1 --- DE- Declination sign (B1950)
16- 17 I2 deg DEd Declination (B1950)
18- 19 I2 arcmin DEm Declination (B1950)
20- 21 I2 arcsec DEs Declination (B1950)
24- 31 F8.4 deg RAdeg Centroid of the VTP detection right ascension
(J2000)
33- 40 F8.4 deg DEdeg Centroid of the VTP detection declination (J2000)
43- 57 A15 --- Class Classification
59-142 A84 --- Comm Comments (1)
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Note (1): For A2147, object B1601+1602 not identified
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Byte-by-byte Description of file: table34.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Notes [GL*c ] Notes (1)
6 A1 --- --- [A]
7- 10 I4 --- ACO Abell Cluster number (Cat. VII/110)
11 A1 --- m_ACO [ab] Multiplicity index on ACO
12 A1 --- n_ACO [*] Individual notes (2)
14- 20 F7.3 deg RAdeg X-ray right ascension (J2000)
21- 27 F7.3 deg DEdeg X-ray declination (J2000)
29- 32 F4.1 10+20cm-2 NH Hydrogen column density (3)
34- 37 I4 s ExpTime RASS exposure time (accumulated)
39- 43 F5.2 s-1 CRvtp PSPC count rate in PHA channels 11 to 235
originally detected by VTP
45- 48 F4.1 arcmin Rvtp Equivalent radius sqrt(AVTP/π) of the
source detected by VTP
50- 54 F5.2 s-1 CR Final PSCP count rate
56- 58 F3.2 s-1 e_CR rms uncertainty on CR
60- 63 F4.1 keV kT ICM gas temperature
64 A1 --- n_kT [e] e: temperature estimated from the
LX-kT relation
66- 70 F5.4 --- z ? Redshift
71 A1 --- n_z [ep] e: redshift estimated from the magnitude
of the 10th-ranked cluster galaxy
72- 74 I3 --- r_z ? Reference for redshift, in refs.dat file
76- 80 F5.1 10-15W/m2 FX Unabsorbed X-ray energy flux in the
0.1 to 2.4keV band (rest frame)
82- 86 F5.2 10+37W LX Intrinsic X-ray luminosity in the
0.1 to 2.4keV band
88- 92 F5.1 10-15W/m2 Fxu Unabsorbed energy flux in the 2-10keV band
94- 95 I2 h RA1h Right ascension (B1950)
96- 97 I2 min RA1m Right ascension (B1950)
98-101 F4.1 s RA1s Right ascension (B1950)
102 A1 --- DE1- Declination sign (B1950)
103-104 I2 deg DE1d Declination (B1950)
105-106 I2 arcmin DE1m Declination (B1950)
107-108 I2 arcsec DE1s Declination (B1950)
110-111 I2 h RAh Right ascension (J2000)
112-113 I2 min RAm Right ascension (J2000)
114-117 F4.1 s RAs Right ascension (J2000)
118 A1 --- DE- Declination sign (J2000)
119-120 I2 deg DEd Declination (J2000)
121-122 I2 arcmin DEm Declination (J2000)
123-124 I2 arcsec DEs Declination (J2000)
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Note (1): Notes:
G: |b2|<20°; "Galactic plane"
L: 20°≤|b2|<30°; low galactic latitude
*: zcluster>0.2, not member of our statistical sample
c: significant fraction of quoted flux may come from embedded point sources
Note (2): Individual notes:
A 750 : resolved into two sources in the EMSS; point source
(AGN contributes ∼30 per cent of the flux)
A 780 : Hydra A
A2572a: HCG 94 (Ebeling et al., 1995MNRAS.275.1155E 1995MNRAS.275.1155E)
A2572b: probably a superposition of two clusters at z∼0.04 and z∼0.15
(Ebeling et al., 1995MNRAS.275.1155E 1995MNRAS.275.1155E)
A3869 : probably an APM cluster rather than the very X-ray faint
ACO cluster at z∼0.04
Note (3): Data from Stark et al. (1992, Cat. J/ApJS/79/77) for DE≥-40°
and Dickey & Lockman (1990ARA&A..28..215) for the remainder of the sky
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 51 A28 --- Aut Author's names
53-166 A114 --- Com Comments
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Acknowledgements:
H. Andernach (catalog A294 in his list)
(End) Francois Ochsenbein [CDS] 28-Jun-2000