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J/ApJ/588/218       i*g* photometry of SDSS EDR galaxies     (Abraham+, 2003)

A new approach to galaxy morphology. I. Analysis of the Sloan Digital Sky Survey Early Data Release. Abraham R.G., van den Bergh S., Nair P. <Astrophys. J. 588, 218 (2003)> =2003ApJ...588..218A
ADC_Keywords: Galaxies, photometry ; Photometry, SDSS ; Redshifts Keywords: galaxies: evolution - galaxies: fundamental parameters Abstract: In this paper we present a new statistic for quantifying galaxy morphology based on measurements of the Gini coefficient of galaxy light distributions. This statistic is easy to measure and is commonly used in econometrics to measure how wealth is distributed in human populations. When applied to galaxy images, the Gini coefficient provides a quantitative measure of the inequality with which a galaxy's light is distributed among its constituent pixels. We measure the Gini coefficient of local galaxies in the Early Data Release of the Sloan Digital Sky Survey and demonstrate that this quantity is closely correlated with measurements of central concentration, but with significant scatter. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 124 930 SDSS Early Data Release g*<16mag Sample
See also: : SDSS Home Page J/AJ/125/1817 : SDSS Early-Type Galaxies Catalog (Bernardi+, 2003) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 2 A2 --- --- [00] 3- 21 A19 --- [AVN2003] Identification number (1) 23- 29 F7.5 --- z Redshift 31- 35 F5.2 --- MOD Distance Modulus (2) 37- 41 F5.2 mag i*mag Isophotal i* band magnitude (3) 43- 47 F5.3 --- i*Con Central i* band concentration 49- 53 F5.3 --- i*Gini The i* band Gini coefficient 55- 59 F5.3 --- e_i*Gini The 1σ error in iGini 61- 65 F5.2 mag/arcsec2 i*SB Mean i* band surface brightness 67- 71 F5.3 --- i*Rat The i* band axial ratio (b/a) 73- 78 F6.3 mag i*zp The i* band zero point 80- 85 F6.3 mag g*mag Isophotal g* band magnitude (4) 87- 91 F5.3 --- g*Con Central g* band concentration 93- 97 F5.3 --- g*Gini The g* band Gini coefficient 99-103 F5.3 --- e_g*Gini The 1σ error in gGini 105-109 F5.2 mag/arcsec2 g*SB Mean g* band surface brightness 111-115 F5.3 --- g*Rat The g* band axial ratio (b/a) 117-122 F6.3 mag g*zp The g* band zero point
Note (1): Designation from SDSS EDR Database. [AVN2003] NNNNNN-NN-N-NNNN-NNNN in Simbad Note (2): Assuming H0=70km/s/Mpc, ΩM=0.3, ΩΛ=0.7 Note (3): Above i*=24.0mag/arcsec2 threshold. Note (4): Above g*=24.5mag/arcsec-2 threshold
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 31-Jul-2003
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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