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 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:
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FileName Lrecl Records Explanations
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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
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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
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Bytes Format Units Label Explanations
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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)
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Note (1): ":" stands for uncertain index
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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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 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 Mg2 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 Mgb 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 60µm flux normalized to Virgo
distance (5)
112-115 I4 Jy F100um IRAS 100µm 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)
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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 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
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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