VII/256 Groups of Galaxies from CfA2 Redshift Survey (Mahtessian++, 2010)
The List of Groups of Galaxies Based on CfA2 Redshift Survey.
Mahtessian A.P., Movsessian V.G.
<Astrophysics, 53, 70 (2010)>
=2010Ap.....53...70M 2010Ap.....53...70M
=2010Afz....53...83M 2010Afz....53...83M
ADC_Keywords: Clusters, galaxy ; Galaxy catalogs ; Magnitudes ;
Radial velocities ; Velocity dispersion
Description:
The catalog contains statistically homogeneous and physically well
graunded groups of galaxies based on the CfA2 redshift survey (Cat.
J/ApJS/121/287) in the area of space 1000km/s≤cz≤15000km/s,
|bII|≥20°. For identification of groups we used a modification
of a friends of friends (FoF) method. Principles of friendship and
definition of values of presented there free parameters described in
Mahtessian (1988Afz....28..255M 1988Afz....28..255M, 1997Ap.....40..285M 1997Ap.....40..285M). There are 1971
groups with 2 or more members, for a total of 6787 members (46.3%);
765 of the groups have 3 or more members with 4375 galaxies (28.1%).
The others 8790 (56.4%) galaxies make a sample of "single" galaxies.
The catalog includes group numbers, numbers of members, equatorial
coordinates, Virgo-centric radial velocities, line-of-sight-velocity
dispersions, integrated group luminosities, and relative quantity of
false members.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 6787 Data of groups members
table2.dat 69 1971 Mean parameters of groups
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See also:
J/ApJS/121/287 : The CfA redshift survey (CfA2S) catalog (Huchra+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Group Number of group
6- 16 A11 --- Galaxy Galaxy name, as in CfA2 (Cat. J/ApJS/121/287)
19- 20 I2 h RAh Right ascension (1950)
22- 25 F4.1 min RAm [0/60] Right ascension (1950)
27 A1 --- DE- Declination sign (1950)
28- 29 I2 deg DEd Declination (1950)
31- 32 I2 arcmin DEm [0/60] Declination (1950)
34- 38 F5.2 mag magc Apparent magnitude of galaxy corrected from
galactic absorption (Sandage,
1973ApJ...183..711S 1973ApJ...183..711S) and by K damping (Yang
et al., 2005MNRAS.356.1293Y 2005MNRAS.356.1293Y.)
40- 44 I5 km/s RVc Virgo-centric radial velocities of galaxy
(Mahtessian, 1997Ap.....40..285M 1997Ap.....40..285M)
46- 50 A5 --- T Morphological type of galaxy by CfA2
(99 means, that the type is unknown)
52- 56 I5 km/s RVC Radial velocities of galaxy relative to the
group centre
58- 61 F4.2 Mpc RC Projected distance of galaxy to group centre
63- 68 F6.2 mag MAG Absolute magnitude of galaxy
70- 77 E8.3 solLum Lum Luminosity of galaxy
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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- 4 I4 --- Group Group number
6- 7 I2 h RAh A mean right ascension of group (1950)
9- 12 F4.1 min RAm [0/60] A mean right ascension of group (1950)
14 A1 --- DE- Declination sign (1950)
15- 16 I2 deg DEd A mean declination of group (1950)
18- 19 I2 arcmin DEm [0/60] A mean declination of group (1950)
21- 23 I3 --- Ng Number of visible members of group
25- 29 I5 km/s VG Mean Virgocentric velocity of group
31- 33 I3 km/s sigma A dispersion of radial velocity of members
of group
35- 39 F5.3 Mpc Rmean Mean distance of members of group from its
centre
41- 45 F5.3 Mpc Rmax Group radius: the greatest distance of
members of group from its centre
47- 54 E8.3 solLum Lobs Total luminosity of visible members of group
56- 63 E8.3 solLum Ltot Total luminosity both visible, and invisible
members of group
65- 69 F5.3 % FIC Relative quantity of false members of groups
in percentage (Mahtessian, 1998Ap.....41..308M 1998Ap.....41..308M)
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Acknowledgements:
A.P. Mahtessian, amahtes(at)bao.sci.am
References:
Mahtessian, Astrofizics, 28, 255, 1988, 1988Afz....28..255M 1988Afz....28..255M (Ap, 28, 150)
Mahtessian, Astrofizics, 40, 45, 1997, 1997Ap.....40...25M 1997Ap.....40...25M
Mahtessian, Astrofizics, 41, 473, 1998, 1998Ap.....41..308M 1998Ap.....41..308M
Mahtessian, Astrofizics, 50, 535, 2007, 2007Ap.....50..440M 2007Ap.....50..440M
(End) Patricia Vannier [CDS] 18-Dec-2009