J/A+A/582/A86 Catalogue of features in the S4G (Herrera-Endoqui+, 2015)
Catalogue of the morphological features in the Spitzer Survey of Stellar
Structure in Galaxies (S4G).
Herrera-Endoqui M., Diaz-Garcia S., Laurikainen E., Salo H.
<Astron. Astrophys. 582, A86 (2015)>
=2015A&A...582A..86H 2015A&A...582A..86H (SIMBAD/NED BibCode)
ADC_Keywords: Atlases ; Galaxy catalogs ; Galaxies, nearby ; Galaxies, ring ;
Galaxies, IR
Keywords: atlases - catalogues - galaxies: statistics - galaxies: structure
Abstract:
A catalogue of the features for the complete Spitzer Survey of Stellar
Structure in Galaxies (S4G), including 2352 nearby galaxies, is
presented. The measurements are made using 3.6um images, largely
tracing the old stellar population; at this wavelength the effects of
dust are also minimal. The measured features are the sizes,
ellipticities, and orientations of bars, rings, ringlenses, and
lenses. Measured in a similar manner are also barlenses (lens-like
structures embedded in the bars), which are not lenses in the usual
sense, being rather the more face-on counterparts of the boxy/peanut
structures in the edge-on view. In addition, pitch angles of spiral
arm segments are measured for those galaxies where they can be
reliably traced. More than one pitch angle may appear for a single
galaxy. All measurements are made in a human- supervised manner so
that attention is paid to each galaxy.
We create a catalogue of morphological features in the complete S4G.
We used isophotal analysis, unsharp masking, and fitting ellipses to
measured structures.
We find that the sizes of the inner rings and lenses normalized to
barlength correlate with the galaxy mass: the normalized sizes
increase toward the less massive galaxies; it has been suggested that
this is related to the larger dark matter content in the bar region in
these systems. Bars in the low mass galaxies are also less
concentrated, likely to be connected to the mass cut-off in the
appearance of the nuclear rings and lenses. We also show observational
evidence that barlenses indeed form part of the bar, and that a large
fraction of the inner lenses in the non-barred galaxies could be
former barlenses in which the thin outer bar component has dissolved.
Description:
Table 2 contains the properties of bars, ring- and lens-structures in
the S4G. Data for bars contains the visual estimated barlength, the
maximum ellipticity in the bar region, the visual estimated position
angle, and the barlength obtained from the ellipticity maximum. They
are given in both the sky plane and the disk plane, the conversion is
made using P4 orientation parameters (Salo et al.,
2015ApJS..219....4S 2015ApJS..219....4S; Table 1). For bars the disk plane values are
given only when a reliable ellipticity maximum was found and the
galaxy inclination i<65 deg. For other features the parameters are
obtained from fitting ellipses to points tracing the structure. A
quality flag for our measurement is also given: 1 indicates a good fit
and unambiguously identified feature, 2 indicates a hard to trace
feature, 3 indicates an uncertain feature identification (due to high
inclination of host galaxy or incomplete feature).
Table 3 contains the properties of spiral arms in the S4G. Type of
spiral arms, the pitch angle, the inner and the outer radius are given
for every spiral segment (see the catalogue web page). The type of
spiral arms are taken from Buta et al. (2015ApJS..217...32B 2015ApJS..217...32B, Cat.
J/ApJS/217/32): G for grand design, M for multiple, and F for
flocculent spiral arms. Our estimation of the quality of the fit is
also given (1.0 = good; 2.0 = acceptable).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 116 2387 Properties of bars, ring- and lens-structures
in the S4G
table3.dat 76 1854 Properties of spiral arms in the S4G;
corrected version sent by the author
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See also:
J/PASP/122/1397 : Spitzer Survey of Stellar Structure in Galaxies (Sheth+ 2010)
J/ApJS/190/147 : Mid-IR galaxy morphology from S4G (Buta+, 2010)
J/ApJ/772/135 : 3.6um surface brightness from S4G (Zaritsky+, 2013)
J/MNRAS/441/1992 : Galaxies with disc breaks in S4G and NIRS0S (Laine+, 2014)
J/MNRAS/444/3015 : Morphologies of S4G galaxies (Laine+, 2014)
J/A+A/569/A91 : Optical imaging for S4G (Knapen+, 2014)
J/MNRAS/441/1992 : Galaxies with disc breaks in S4G and NIRS0S (Laine+, 2014)
J/ApJS/217/32 : S4G galaxy morphologies in the CVRHS system (Buta+, 2015)
J/ApJ/799/159 : Globular cluster populations in S4G galaxies (Zaritsky+ 2015)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy name
13- 39 A27 --- Class Morphological classification
42- 46 A5 --- Type Type of feature (1)
48- 52 F5.1 arcsec sma Semi-major axis
58- 60 I3 deg PA Position angle
63- 69 F7.2 --- Ell ?=-999 Ellipticity
72- 77 F6.1 arcsec smaEll ?=-999 Semi-major axis from ellipticity
80- 85 F6.1 arcsec dsma ?=-999 Deprojected semi-major axis
89- 92 I4 deg dPA ?=-999 Deprojected position angle
95-101 F7.2 --- dEll ?=-999 Deprojected ellipticity
104-109 F6.1 arcsec dsmaEll ?=-999 Deprojexted semi-major axis from Ell
116 I1 --- Qual [1/3] Quality flag (2)
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Note (1): Type of structures (see Section 3 for details) as follows:
R = Outer ring
R' = Outer pseudo-ring
R1 = Outer ring with type 1 morphology
R'1 = Outer pseudo-ring with type 1 morphology
R2 = Outer ring with type 2 morphology
R'2 = Outer pseudo-ring with type 2 morphology
_RL, RL, R_L = Outer ringlens
_R'L, R'L, R'_L = Outer pseudo-ringlens
L = Outer lens
r = Inner ring
r', _rs, rs, r_s = Inner pseudo-ring
_rl, rl, r_l = Inner ringlens
_r'l, r'l, r'_l = Inner pseudo-ringlens
l, ls, sl = Inner lens
bl = Barlens
nr = Nuclear ring
nr' = Nuclear pseudo-ringlens
nrl = Nuclear ringlens
nr'l = Nuclear pseudo-ringlens
nl = Nuclear lens
nl' = Nuclear lens (not fully developed)
bar = Bar
Combinations:
R'1R'2 = Outer pseudo-ring with type 1 and 2 morphology
R1L = Outer ringlens with type 1 morphology
R1'L = Outer pseudo-ringlens with type 1 morphology
R2L = Outer ringlens with type 2 morphology
R2'L = Outer pseudo-ringlens with type 2 morphology
Note (2): Quality flags as follows:
1 = indicates a good fit and unambiguously identified feature
2 = indicates a hard to trace feature
3 = indicates an uncertain feature identification (due to high
inclination of host galaxy or incomplete feature)
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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- 10 A10 --- Name Galaxy name
13- 36 A24 --- Class Morphological classification
39 A1 --- Type Type of arms (3)
42- 44 A3 --- Segment Segment
48- 52 F5.1 deg Pitchang Pitch angle
56- 60 F5.1 arcsec ri Inner radius
64- 68 F5.1 arcsec ro Outer radius
74- 76 F3.1 --- Qual [1/2] Quality flag (4)
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Note (3): Type of arms as follows:
G = Grand design
M = Multiple
F = Flocculent
Note (4): Quality flag for spirals as follows:
1.0 = good fit
2.0 = acceptable fit
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Acknowledgements:
Martin Herrera Endoqui, martin.herreraendoqui(at)oulu.fi
References:
Sheth et al., 2010PASP..122.1397S 2010PASP..122.1397S
The Spitzer Survey of Stellar Structure in Galaxies (S4G)
Salo et al., 2015ApJS..219....4S 2015ApJS..219....4S
The Spitzer Survey of Stellar Structure in Galaxies (S4G): Multi-component
Decomposition Strategies and Data Release
Buta et al., 2015ApJS..217...32B 2015ApJS..217...32B
A Classical Morphological Analysis of Galaxies in the Spitzer Survey of
Stellar Structure in Galaxies (S4G)
History:
* 14-Oct-2015: on-line version
* 25-Jan-2017: table2 corrected (from author)
* 23-Apr-2019: table3, ri and ro columns corrected (from author)
(End) M. Herrera Endoqui [Univ. of Oulu, Finland], P. Vannier [CDS] 19-Aug-2015