J/MNRAS/444/3015 Morphologies of S4G galaxies (Laine+, 2014)
Spitzer/Infrared Array Camera near-infrared features in the outer parts of
S4G galaxies.
Laine S., Knapen J.H., Munoz-Mateos J.-C., Kim T., Comeron S., Martig M.,
Holwerda B.W., Athanassoula E., Bosma A., Johansson P.H., Erroz-Ferrer S.,
Gadotti D.A., Gil De Paz A., Hinz J., Laine J., Laurikainen E.,
Menendez-Delmestre K., Mizusawa T., Regan M.W., Salo H., Sheth K.,
Seibert M., Buta R.J., Cisternas M., Elmegreen B.G., Elmegreen D.M.,
Ho L.C., Madore B.F., Zaritsky D.
<Mon. Not. R. Astron. Soc., 444, 3015-3039 (2014)>
=2014MNRAS.444.3015L 2014MNRAS.444.3015L
ADC_Keywords: Galaxy catalogs ; Photometry, infrared ; Morphology
Keywords: atlases - catalogues - galaxies: interactions - galaxies: peculiar -
galaxies: structure - infrared: galaxies
Abstract:
We present a catalogue and images of visually detected features, such
as asymmetries, extensions, warps, shells, tidal tails, polar rings,
and obvious signs of mergers or interactions, in the faint outer
regions (at and outside of R25) of nearby galaxies. This catalogue
can be used in future quantitative studies that examine galaxy
evolution due to internal and external factors. We are able to
reliably detect outer region features down to a brightness level of
0.03MJy/sr/pixel at 3.6µm in the Spitzer Survey of Stellar
Structure in Galaxies (S4G). We also tabulate companion galaxies. We
find asymmetries in the outer isophotes in 22±1% of the sample. The
asymmetry fraction does not correlate with galaxy classification as an
interacting galaxy or merger remnant, or with the presence of
companions. We also compare the detected features to similar features
in galaxies taken from cosmological zoom re-simulations. The simulated
images have a higher fraction (33%) of outer disc asymmetries, which
may be due to selection effects and an uncertain star formation
threshold in the models. The asymmetries may have either an internal
(e.g. lopsidedness due to dark halo asymmetry) or external origin.
Description:
The sample we used is the full S4G sample (Sheth et al.,
2010PASP..122.1397S 2010PASP..122.1397S, Cat. J/PASP/122/1397), consisting of 2352
galaxies (10 of the 2331 galaxies specified in Sheth et al. 2010 were
not observed, mostly because they were close to a very bright star,
and 31 galaxies were added) with systemic velocity Vsys,radio<
3000km/s, corresponding to a distance d<45Mpc for a
Planck-mission-based Hubble constant (Ade et al., 2014A&A...566A..54P 2014A&A...566A..54P)
of 67km/s/Mpc and a distance d<41Mpc for a Hubble constant of
71km/s/Mpc, total corrected blue magnitude mBcorr<15.5, blue light
isophotal angular diameter D25>1.0-arcmin, and a Galactic latitude
|b|>30° (Sheth et al. 2010). All the galaxies in this sample were
imaged with the Spitzer Space Telescope's IRAC. We used the channel 1
(3.6um) mosaics made of eight 30-s frames per spatial position.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 1047 Morphological outer features of S4G galaxies
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See also:
J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Galaxies (Sheth+ 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Galaxy name
16- 17 I2 --- TT ?=99 T type (1)
19- 24 F6.2 mag M3.6 ?=-99.99 Absolute 3.6um magnitude (in AB mag) (1)
26- 36 A11 --- Class Classification elements (2)
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Note (1): The morphological T-type is based on classification in the 3.6um
IRAC images (Buta et al., 2015ApJS..217...32B 2015ApJS..217...32B). The 3.6um absolute
AB magnitudes are from Munoz-Mateos et al. (2015, in press).
99/-99.99 is used if the value could not be derived from the data,
for example if the galaxies are right next to a very bright star, are
resolved out (did not have a continuous disc) or have an extremely low
surface brightness
Note (2): Classification symbols are:
A = asymmetry
E = extension
W = warp
TT = tidal tail
S = shell
I = interaction
M = merger
PR = polar ring
C = companion
U = uncertain: any feature detection was very uncertain, often due to
a bright star right next to a galaxy or a low surface brightness
light distribution that gives the galaxy a very patchy appearance.
? = A question mark (?) after a classification letter means that the
classification of that feature as such was uncertain (but not due to
an overall uncertainty factor which is marked by the 'U' letter).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Apr-2015