J/MNRAS/397/1756 Fourier-derived parameters of the CIG sample (Durbala+, 2009)
Fourier photometric analysis of isolated galaxies in the context of the
AMIGA project.
Durbala A., Buta R., Sulentic J.W., Verdes-Montenegro L.
<Mon. Not. R. Astron. Soc., 397, 1756-1775 (2009)>
=2009MNRAS.397.1756D 2009MNRAS.397.1756D
ADC_Keywords: Galaxies, photometry ; Morphology ; Colors
Keywords: galaxies: evolution - galaxies: fundamental parameters -
galaxies: general - galaxies: photometry - galaxies: spiral -
galaxies: structure
Abstract:
We present here the results of a Fourier photometric decomposition of
a representative sample of ∼100 isolated CIG galaxies (Catalog of
Isolated Galaxies) in the morphological range Sb-Sc. This study is an
integral part of the AMIGA (Analysis of the Interstellar Medium of
Isolated Galaxies) project. It complements the photometric analysis
presented in our previous paper for the same sample of disc galaxies
by allowing a description of the spiral structure morphology. We also
estimate dynamical measures like torque strength for bar and spiral,
and also the total non-axisymmetric torque by assuming a constant
mass-to-light ratio, and explore the interplay between the spiral and
bar components of galaxies. Both the length (lbar) and the contrast
(e.g. A2b) of the Fourier bars decrease along the morphological
sequence Sb-Sbc-Sc, with bars in earlier types being longer and
showing higher contrast. The bars of Sb galaxies are ∼ three times
longer than the bars in Sc types, consistent with our previous study.
We find that the longer bars are not necessarily stronger (as
quantified by the torque Qbmeasure), but longer bars show a higher
contrast A2b, in very good agreement with theoretical predictions.
Our data suggest that bar and spiral components are rather independent
in the sense that the torque strengths of the two components are not
correlated. The total strength Qg is a very reliable tracer of the
bar strength measure Qb, the two quantities showing a very tight
linear correlation. Comparison with a similar sample of disc galaxies
(same morphological range) extracted from the OSUBGS (Ohio State
University Bright Galaxy Survey) indicates that the isolated CIG/AMIGA
galaxies host significantly longer Fourier bars and possibly show a
different distribution of spiral torque Qs. The Fourier analysis
also revealed a potential case of counterwinding spiral structure
(KIG652/NGC5768), which deserves further kinematic study. We find that
m=2 (i.e. dominating two-armed pattern) is the most common spiral arm
multiplicity among the sample of Sb-Sc CIG/AMIGA galaxies (∼40 per
cent), m=2 and 3 and m=1 and 2 are found in ∼28 and ∼13 per cent of
isolated galaxies, respectively.
Description:
Revision of the main properties for all AMIGA galaxies. Because a
significant number of new data are available for the sample since the
AMIGA project started, apparent magnitudes, morphological types,
distances, and optical luminosities for the CIG sample have been
updated. In the frame of the Wf4Ever project, the revision of these
properties was partially automated by the implementation of scientific
workflows that ask for and gather values of some of the properties for
all AMIGA galaxies from the HyperLeda catalog.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 75 93 Fourier-derived parameters in i band for the
CIG/KIG galaxies in our sample
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See also:
VII/82 : Catalogue of Isolated Galaxies (Karachentseva+ 1986)
J/A+A/411/391 : AMIGA project. CIG galaxies revised positions (Leon+, 2003)
J/A+A/436/443 : AMIGA I Velocities of CIG galaxies (Verdes-Montenegro+, 2005)
J/A+A/449/937 : AMIGA II Morphological refinement (Sulentic+, 2006)
J/A+A/462/507 : AMIGA III IRAS data (Lisenfeld+, 2007)
J/A+A/470/505 : AMIGA IV Neighbours around CIG galaxies (Verley+, 2007)
J/A+A/472/121 : AMIGA V Isolation parameters (Verley+, 2007)
J/A+A/485/475 : AMIGA VI Radio fluxes of the isolated galaxies (Leon+ 2008)
J/A+A/486/73 : AMIGA VII FIR and radio study (Sabater+, 2008)
J/A+A/532/A117 : AMIGA VIII Flux ratio asymmetry parameter (Espada+, 2011)
J/A+A/534/A102 : AMIGA IX Molecular gas properties (Lisenfeld+, 2011)
J/A+A/540/A47 : AMIGA X Isolated galaxy colors (Fernandez Lorenzo+, 2012)
J/A+A/545/A15 : AMIGA XI Optical nuclear activity (Sabater+, 2012)
J/MNRAS/434/325 : 452 AMIGA gal. physical parameters (Fernandez Lorenzo+ 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- CIG [1/1051] Catalog of Isolated Galaxy number
(VII/82) number, <K73 NNNN> in Simbad
7- 9 I3 deg PA [0/180] Mean orientation angle (1)
11 A1 --- met [abc] Bulge deprojection method used (2)
13- 17 F5.3 --- Qg Total strength of galaxy Qg (3)
19- 23 F5.3 --- e_Qg Total strength standard deviation (SD)
25- 29 F5.3 --- Qb ? Bar strength (3)
31- 35 F5.3 --- e_Qb ? Bar strength standard deviation (SD)
37- 41 F5.3 --- Qs Spiral strength (3)
43- 47 F5.3 --- e_Qs Spiral strength standard deviation (SD)
49- 53 F5.3 --- A2b ? Maximum Fourier relative amplitude A2b (4)
55- 59 F5.3 --- A4b ? Maximum Fourier relative amplitude A4b (4)
61- 65 F5.3 --- A6b ? Maximum Fourier relative amplitude A6b (4)
67- 70 F4.1 arcsec lbar ? Fourier bar length
72- 75 F4.1 arcsec r(Qb) ? Radius of maximal bar torque
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Note (1): measured as explained in Section 3.1.1 of the paper.
Note (2): Methods as follows:
a = in most situations, the deprojection procedure automatically leads
to a circularly shaped bulge
b = in some cases the bulge is already circular in the original image
(prior to deprojection), in which case we subtract the bulge model
given by the budda decomposition code first
c = if neither before nor after deprojection the bulge appears circular
Note (3): the strength Q is defined from the ratio of the maximal tangential
force Ft to the averaged radial force Fr: Q=max[Ft(φ]/<Fr(φ)>,
computed over the bar+disk image (Qb), the spiral+disk image (Qs),
or the total image (Qg).
Note (4): the Fourier amplitudes are defined as Am=max[Im/I0],
maximum of the relative Fourier intensities, where m is an even number.
The Am indicate the contribution of the non-axisymmetric compopnents
relative the axisymmetric background
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Acknowledgements:
Lourdes Verdes-Montenegro, lourdes(at)iaa.es
(End) Patricia Vannier [CDS] 26-Nov-2013