J/A+A/478/353 Structural properties of disk galaxies (Mendez-Abreu+, 2008)
Structural properties of disk galaxies.
I. The intrinsic equatorial ellipticity of bulges.
Mendez-Abreu J., Aguerri J.A.L., Corsini E.M., Simonneau E.
<Astron. Astrophys., 478, 353-369 (2008)>
=2008A&A...478..353M 2008A&A...478..353M
ADC_Keywords: Galaxies, photometry ; Morphology
Keywords: galaxies: bulges - galaxies: formation -
galaxies: fundamental parameters - galaxies: photometry -
galaxies: statistics - galaxies: structure
Abstract:
A variety of formation scenarios have been proposed to explain the
diversity of properties observed in bulges. Studying their intrinsic
shape can help to constrain the dominant mechanisms at the epochs of
their assembly.
The structural parameters of a magnitude-limited sample of 148
unbarred S0-Sb galaxies were derived in order to study the
correlations between bulges and disks, as well as the probability
distribution function of the intrinsic equatorial ellipticity of
bulges.
We present a new fitting algorithm (GASP2D) to perform two-dimensional
photometric decomposition of the galaxy surface-brightness
distribution. This was assumed to be the sum of the contribution of a
bulge and disk component characterized by elliptical and concentric
isophotes with constant (but possibly different) ellipticity and
position angles. Bulge and disk parameters of the sample galaxies were
derived from the J-band images, which were available in the Two Micron
All Sky Survey. The probability distribution function of the
equatorial ellipticity of the bulges was derived from the distribution
of the observed ellipticities of bulges and misalignments between
bulges and disks.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 100 148 Main properties and structural bulge and disk
parameters of the galaxies in the sample
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Galaxy Galaxy name
16- 29 A14 --- MType Morphological classification from RC3
(Cat. VII/155)
31- 34 F4.2 mag Jmag Total observed J-band magnitude from 2MASS
(Cat. II/246)
36- 39 I4 km/s V3K Radial velocity with respect to the CMB
from LEDA
41- 45 F5.1 Mpc Dist Distance (1)
46 A1 --- n_Dist [*] * for distance been taken from Tully
(1988, Cat. VII/145)
48- 50 I3 km/s sigma0 ?=- Central velocity dispersion from LEDA
52- 56 F5.2 mag/arcsec2 SuBreff Bulge effective surface brightness
58- 61 F4.1 arcsec reff Bulge effective radius
63- 66 F4.2 --- n Bulge shape parameter (2)
68- 71 F4.2 --- qb Bulge axis ratio (qb = 1-e)
73- 77 F5.1 deg PAb Bulge position angle
79- 83 F5.2 mag/arcsec2 SuBr0 Disk central surface brightness
85- 89 F5.1 arcsec h Disk scale length
91- 94 F4.2 --- qd Disk axis ratio
96-100 F5.1 deg PAd Disk position angle
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Note (1): Distance obtained as V3K/H0 with H0=75km/s/Mpc.
Note (2): the shape parameter is given by Eq.(1) of paper:
log(I(x,y)/Ie) = -bn((rb/re)1/n - 1)
where re is the effective (half-light) radius,
Ie the surface brightness at re
and rb a 'distance' to the center (cf paper)
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Acknowledgements:
Jairo Mendez-Abreu, jairo.mendez(at)oapd.inaf.it
(End) Patricia Vannier [CDS] 21-Apr-2008