J/ApJ/511/65 Einstein images of galaxy clusters (Jones & Forman, 1999)
Einstein Observatory Images of Clusters of Galaxies
Jones C., and Forman W.
<Astrophys. J. 511, 65 (1999)>
=1999ApJ...511...65J 1999ApJ...511...65J
ADC_Keywords: Clusters, galaxy; X-ray sources
Mission_Name: Einstein
Keywords: galaxies: clusters: general - intergalactic medium -
surveys - X-rays: galaxies
Abstract:
We present the X-ray characteristics of a sample of 368 clusters of
galaxies with redshifts less than 0.2 observed with the Einstein
Imaging Proportional Counter. For each cluster, we measure the
0.5-4.5keV counting rate and compute the 0.5-4.5keV source luminosity, as
well as the bolometric luminosity within fixed metric radii. We detect
85% of Abell clusters with z<0.1, demonstrating that the large
majority of these optically selected clusters are not the results of
chance superpositions. For 163 clusters, we measure their X-ray
surface brightness profiles and determine their core radii. For
∼230 clusters, we then use either our measured core radii and values,
or mean values derived for this sample, to measure central gas
densities and gas masses. We use estimated or measured cluster gas
temperatures, along with the derived gas-density profiles, to estimate
total cluster masses, under the assumptions that the gas is isothermal
and in hydrostatic equilibrium.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 105 396 Cluster properties from the Einstein survey
table4.dat 104 252 Physical cluster parameters of a subset of the
Einstein survey
refs.dat 112 36 Redshift references for table3.dat
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See also:
VII/4 : Abell and Zwicky Clusters of Galaxies (Abell+ 1974)
VII/110 : Rich Clusters of Galaxies (Abell+ 1989)
VII/165 : Catalogue of measured redshifts of Abell clusters of galaxies
IX/18 : EINSTEIN extended source survey (EXSS) (Oppenheimer+ 1997)
J/A+A/278/379 : X-ray Emission from Abell Clusters of Galaxies (Briel+ 1993)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Cluster name
16- 18 A3 --- q_RAh [ac=] Indicates less accurate coordinates
19- 20 I2 h RAh Right Ascension (B1950)
22- 25 F4.1 min RAm Right Ascension (B1950)
27- 30 F4.1 s RAs ? Right Ascension (B1950)
33 A1 --- DE- Sign of the Declination
34- 35 I2 deg DEd Declination (B1950)
37- 38 I2 arcmin DEm Declination (B1950)
42- 43 I2 arcsec DEs ? Declination (B1950)
45- 50 F6.4 --- z Redshift
52- 55 A4 --- r_z Redshift reference (see refs.dat)
57- 63 F7.4 ct/s cts Count rate (counts/s)
65- 70 F6.4 ct/s e_cts Uncertainty in cts
72- 75 F4.2 Mpc Rad Radius of the region measured
76 A1 --- l_XLum Limit on Xlum
77- 82 F6.3 10+37W XLum Xray (0.5-4.5keV) luminosity (10+44 ergs/s)
87- 91 F5.3 10+37W e_XLum ? Uncertainty in XLum
95- 99 F5.2 keV kT ? Temperature multiplied by the
Boltzman constant
101-105 F5.2 10+20cm-2 ColD Hydrogen column depth (10+20/cm3)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Cluster name
13- 18 F6.3 10+37W XLum Xray (0.5-4.5keV) luminosity
(10+44 ergs/s)
20- 25 F6.3 10+37W BLum Bolometric luminosity (10+44 ergs/s)
27- 30 F4.2 Mpc Rad Cluster radius
36- 39 F4.2 Mpc e_Rad ? Uncertainty in Rad
41- 44 F4.2 --- beta Radial surface brightness parameter
SB(0).(1+(R/α)2)(-3β+0.5)
50- 53 F4.2 --- e_beta ? Uncertainty in β
55 A1 --- Meth [mDdr] Method used (1)
57- 60 F4.2 10+10yr Cool Radiative cooling timescale (10+10 years)
62- 67 F6.3 10-3cm-3 DenG Gas density
69- 72 F4.2 10+14solMass MG1 Gas mass within 1 Mpc
78- 81 F4.2 10+14solMass MGR ? Gas mass within 5 core radii
83- 86 F4.2 10+14solMass MT1 Total mass within 1 Mpc
88- 92 F5.2 10+14solMass MTR Total mass within 5 core radii
94- 96 F3.1 --- BM Bautz-Morgan classification
98 I1 --- R Richness of the cluster
100-102 I3 --- NG Number of galaxies in cluster
104 A1 --- Class [esucpdog] Xray Morphological class (2)
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Note (1):
m = Central cluster region excluded from fit
d = β fixed at 0.6
r = cluster size determined by ratio of cluster counts calculated
at different cluster radii
D = clusters with unconstrained structural parameters
Note (2):
s = single symmetric peak
o = offset center
e = elliptical
c = complex, multiple structures
d = double, roughly equal components
p = primary with small secondary
g = primarily galaxy emission
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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- 4 A4 --- Code Initials of the reference
8- 26 A19 --- BibCode Bicode of the reference
30-129 A100 --- Text Author, year and description of reference
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History:
From ApJ electronic edition
(End) Greg Schwarz (AAS) 10-Feb-2000