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J/A+A/423/833       Photometry in elliptical galaxies        (Michard+, 2004)

Peculiarities and populations in elliptical galaxies. I. An old question revisited. Michard R., Prugniel P. <Astron. Astrophys., 423, 833-847 (2004)> =2004A&A...423..833M
ADC_Keywords: Galaxies, photometry Keywords: galaxies: elliptical and lenticulars, CD - galaxies: photometry Description: Morphological peculiarities, as defined from isophote asymmetries and number of detected shells, jets or similar features, have been estimated in a sample of 117 E classified galaxies, and qualified by an ad hoc S2 index. Objects with S2<1 are "normal" (Nop subsample), the other are "peculiar" (Pec subsample). The two subsamples are intercompared as regards the Fundamental Plane, Faber-Jackson relation, dust content from IRAS fluxes, occurence of Kinematically Distinct Cores and stellar populations. The Nop subsample objects displays tight correlations between central velocity dispersion (or mass) and the population indices U-B, B-V, B-R, V-I, Mg2, Hbeta, <Fe>, Mgb. Part of the Pec objects deviate from these correlations, with blue "residuals" indicating a Younger Population mixed with the old one. This does not occur for other Pec objects. This subsample is thus classified in two families: i.e. the 'YP', or NGC 2865 family, and the 'NP' or NGC 3923 one. This distinction is quantified by a Mean Index of a Younger Population, or 'MIYP' with near zero values for the 'NP' objects and relatively large negative values for the 'YP'. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table7.dat 79 37 Residuals of colours- and line-indices of ellipticals in the Pec subsample table10.dat 130 117 Data compiled and derived for the full sample
See also: VII/184 : Survey of 108 E-S0 galaxies (Michard+, 1993-94) J/A+A/309/749 : Fundamental plane of early type galaxies (Prugniel+ 1996) J/A+AS/103/573 : UBVRI Photometry of bright southern galaxies (Poulain+ 1994) J/A+AS/104/179 : Surface photometry in Shapley-Ames galaxies (Goudfrooij+ 1994) J/ApJS/70/329 : IRAS flux densities for early-type galaxies (Knapp+ 1989) Byte-by-byte Description of file: table7.dat
Bytes Format Units Label Explanations
1- 7 A7 --- Name NGC or IC designation 9- 12 F4.1 --- S2 Peculiarity index (G1) 15- 20 F6.3 mag D(U-B) U-B residual 22- 27 F6.3 mag D(B-V) B-V residual 29- 34 F6.3 mag D(B-R) ?=9.990 B-R residual 36- 41 F6.3 mag D(V-I) ?=9.990 V-I residual 43- 48 F6.3 mag D(Mg2) Mg2 index residual 50- 54 F5.2 0.1nm D(Hbeta) ?=9.99 Hbeta index residual 56- 60 F5.2 0.1nm D(<Fe>) ?=9.99 <Fe> index residual 62- 66 F5.2 0.1nm D(Mg_b) ?=9.99 Mgb index residual 68- 73 F6.3 mag MIYP Mean Index of Young Population 75- 77 A3 --- Pop Family YP (Young population) or NP (1)
Note (1): ":" stands for uncertain index
Byte-by-byte Description of file: table10.dat
Bytes Format Units Label Explanations
2- 8 A7 --- Name NGC or IC number 10- 14 F5.2 mag mu1 Distance modulus from Prugniel & Simien, 1996, Cat. J/A+A/309/749 16- 20 F5.2 mag mu2 ?=0 Distance modulus from Tonry et al., 2001ApJ...546..681T 22- 26 F5.2 mag BT B total magnitude from Prugniel & Simien, 1996, Cat. J/A+A/309/749 28- 31 F4.2 [arcsec] logRe Adopted effective radius (1) 33- 36 F4.2 --- eps Ellipticity near Re (2) 38- 43 F6.2 mag BMAG1 Absolute B magnitude from BT and mu1 45- 50 F6.2 mag BMAG2 Absolute B magnitude from BT and mu2 52- 55 F4.2 mag U-B Integrated U-B colour within Re (3) 57- 60 F4.2 mag B-V Integrated B-V colour within Re (3) 62- 65 F4.2 mag B-R Integrated B-R colour within Re (3) 67- 70 F4.2 mag V-I Integrated V-I colour within Re (3) 72- 76 F5.3 mag Mg2 Mg_2_ index (1) 78- 81 F4.2 0.1nm Hbeta Average Hbeta index (4) 83 I1 --- W1 Number of Hbeta index sources 85- 88 F4.2 0.1nm <Fe> Average <Fe> index (4) 90 I1 --- W2 Number of <Fe> index sources 92- 95 F4.2 0.1nm Mgb Average Mg_b_ index (4) 97 I1 --- W3 Number of Mgb index sources 99-101 I3 km/s sigma0 Central velocity dispersion 103-105 I3 km/s Vrot Maximum rotational velocity 107-110 I4 Jy F60um IRAS 60mum flux normalized to Virgo distance (5) 112-115 I4 Jy F100um IRAS 100mum flux normalized to Virgo distance (5) 117-120 F4.2 --- Dens Density of environment (unity in Virgo Cl.) 122-125 A4 --- Type Classification as boxy, disky, undeterminate 127-130 F4.1 --- S2 Peculiarity index (G1)
Note (1): From Prugniel & Simien, 1996, Cat. J/A+A/309/749 Note (2): From Goudfrooij et al., 1994, Cat. J/A+AS/104/179 and Michard & Marchal, 1994A&AS..105..481M, Cat. VII/184 Note (3): Colours are compiled from several sources with preference for Poulain P., Nieto, J.-L., 1994, Cat. J/A+AS/103/573 Note (4): The line indices Hbeta, <Fe>, Mgb are compiled from several sources and averaged with a zero-point adjustment. Note (5): The IRAS fluxes at 60 and 100 microns are taken from Knapp et al., 1989, Cat. J/ApJS/70/329 and corrected to the Virgo Cluster distances
Global Notes: Note (G1): the pecularity index S2 is described in section 2.3.2 of the paper; it takes into account the following elements: - Discrete features classically recognized in possible post-mergers or in perturbed E-galaxies - Asymetries of the outer regions in E-galaxies - anomalous forms of the envelopes Objects with S2<1 are "normal", and the index varies from 0 to slightly above 10 for NGC 2865 and 3923, the most peculiar objects in the sample.
Acknowledgements: Raymond Michard, raymond.michard(at)obspm.fr Philippe Prugniel, prugniel(at)obs.univ-lyon1.fr
(End) Patricia Vannier [CDS] 24-Sep-2004
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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