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J/AJ/137/3942       Fossil galaxy groups                     (La Barbera+, 2009)

The nature of fossil galaxy groups: are they really fossils? La Barbera F., De Carvalho R.R., De La Rosa I.G., Sorrentino G., Gal R.R., Kohl-moreira J.L. <Astron. J., 137, 3942-3960 (2009)> =2009AJ....137.3942L
ADC_Keywords: Clusters, galaxy ; X-ray sources Keywords: galaxies: clusters: general - galaxies: evolution - galaxies: formation - galaxies: fundamental parameters Abstract: We use SDSS-DR4 photometric and spectroscopic data out to redshift z∼0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of 25 fossil groups (FGs), defined as bound systems dominated by a single, luminous elliptical galaxy with extended X-ray emission. We examine possible biases introduced by varying the parameters used to define the sample, and the main pitfalls are also discussed. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 124 46 Properties of fossil group (FG) and field galaxies (FS) galaxies
See also: http://www.sdss.org : SDSS Home Page Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Sequential number, [LDD2009] NN in Simbad 4- 12 F9.5 deg RAdeg Right ascension in decimal degrees (J2000) 14- 21 F8.4 deg DEdeg Declination in decimal degrees (J2000) 23- 27 F5.3 --- z SDSS-DR4 spectroscopic redshift 29- 35 F7.3 mag rMAG r band absolute magnitude of the first-rank galaxy (z=0.1 k-corrected) 37- 40 F4.2 mag DM Magnitude gap of the fossil group, ΔM 42- 46 F5.3 mag g-r g-r colour index (z=0.1 k-corrected)) (1) 48- 51 F4.1 --- dN Density excess around each galaxy, δN 53- 58 F6.2 arcsec gReff Effective radii in g band 60- 65 F6.2 arcsec rReff Effective radii in r band 67- 70 F4.1 --- ng Sersic index in g band 72- 75 F4.1 --- nr Sersic index in r band 77- 82 F6.3 % a4 a4 parameter (describes boxy/disky departures from elliptical shape) 83- 88 F6.3 mag n(g-r) Internal color gradient, ∇(g-r) (mag/dex) 90- 94 F5.2 [10+37W] logLX X-ray luminosity 96-101 F6.3 --- dCM Distance of the galaxy to the red sequence, δCM (3) 103-107 F5.3 [km/s] log(sig) Velocity dispersion 109-111 F3.1 [yr] logAge Age 113-117 F5.2 [Sun] [Z/H] Metallicity 119-122 F4.2 --- [a/Fe] Abundance of α-elements [α/Fe] 124 A1 --- Flag [0/2] Pecularities, 1=fossil group (2)
Note (1): For field galaxies, the values of DM have been randomly assigned. Note (2): Flag as follows: 1 = fossil groups (FG) with extended X-ray contours 2 = field galaxies 0 = fossil group (FG) candidates that are not in the final FG sample because they do not fulfill the X-ray extension criterion Note (3): color distance normalized to the scatter of the red sequence; (see section 6 of paper)
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 19-Oct-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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