J/ApJS/218/6 The Spitzer Interacting Galaxies Survey (SIGS) (Brassington+, 2015)
The Spitzer Interacting Galaxies Survey: a mid-infrared atlas of star formation.
Brassington N.J., Zezas A., Ashby M.L.N., Lanz L., Smith H.A.,
Willner S.P., Klein C.
<Astrophys. J. Suppl. Ser., 218, 6 (2015)>
=2015ApJS..218....6B 2015ApJS..218....6B
ADC_Keywords: Galaxies, IR ; Surveys
Keywords: galaxies: evolution; galaxies: interactions; stars: formation
Abstract:
The Spitzer Interacting Galaxies Survey is a sample of 103 nearby
galaxies in 48 systems, selected using association likelihoods and
therefore free from disturbed morphology biases. All galaxies have
been observed with Infrared Array Camera and MIPS 24µm bands from
the Spitzer Space Telescope. This catalog presents the global flux
densities and colors of all systems and correlations between the
interacting systems and their specific star formation rate (sSFR).
This sample contains a wide variety of galaxy interactions with
systems ranging in mass, mass ratios, and gas-content as well as
interaction strength. This study seeks to identify the process of
triggering star formation in galaxy interactions, therefore, we focus
on the non-active galactic nucleus spiral galaxies only. From this
subset of 70 spiral galaxies we have determined that this sample has
enhanced sSFR compared to a sample of non-interacting field galaxies.
Through optical data we have classified each system by "interaction
strength"; the strongly interacting (Stage 4) galaxies have higher
sSFR values than the weakly (Stage 2) and moderately (Stage 3)
interacting systems. However, the Stage 2 and 3 systems have
statistically identical sSFR properties, despite the lack of optical
interaction signatures exhibited by the Stage 2 galaxies. We suggest
that the similarity of sSFR in these stages could be a consequence of
some of these Stage 2 systems actually being post-perigalactic and
having had sufficient time for their tidal features to fade to
undetectable levels. This interpretation is consistent with the
correlation of sSFR with separation, which we have determined to have
little variation up to 100kpc.
Description:
All 103 galaxies in the Spitzer Interacting Galaxies Survey (SIGS)
sample were observed with the IRAC and the Multiband Imaging
Photometer (MIPS) on the Spitzer Space Telescope (SST). These
observations were obtained through both the archive and our observing
program (PID 20140; PI A. Zezas). A log of all observations (between
2003 Nov and 2008 Aug) is presented in Table 2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 103 Basic properties of all SIGS galaxies
table2.dat 109 110 Spitzer observations log
table4.dat 117 103 Spitzer flux densities for all SIGS galaxies
table6.dat 56 103 Derived physical properties for all SIGS galaxies
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See also:
VII/221 : PSCz catalog (Saunders+, 2000)
VII/155 : Third Reference Cat. of Bright Galaxies (RC3) (de Vaucouleurs+ 1991)
VII/74 : Atlas of Peculiar Galaxies (Arp 1966)
J/PASP/123/1011 : Star Formation Reference Survey (SFRS) (Ashby+, 2011)
J/ApJ/714/1256 : Far-IR star formation rate indicators (Calzetti+, 2010)
J/ApJ/713/330 : Spitzer observations of major-merger galaxies (Xu+, 2010)
J/ApJ/703/1672 : Far-IR and Hα fluxes in galaxies (Kennicutt+, 2009)
J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)
J/ApJ/692/556 : Star forming galaxy templates (Rieke+, 2009)
J/ApJ/676/184 : Peculiar motion away from the Local Void (Tully+, 2008)
J/AJ/133/791 : Spitzer phot. of normal & interacting galaxies (Smith+, 2007)
J/ApJ/633/871 : Positions & photometry of HII knots in M51 (Calzetti+, 2005)
J/AJ/128/2170 : Hα imaging of irregular galaxies (Hunter+, 2004)
J/ApJS/132/37 : Spectroscopy of Southern warm IR galaxies (Kewley+, 2001)
J/ApJS/112/315 : Spectroscopic parameters of Seyfert nuclei (Ho+ 1997)
http://edd.ifa.hawaii.edu/ : The Extragalactic Distance Database (EDD)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [Grp]
4- 5 I2 --- Grp [1/48] Group number (1)
7- 19 A13 --- Name Galaxy name
21- 30 A10 --- Arp Arp galaxy name
32- 33 I2 h RAh Hour of right ascension (J2000)
35- 36 I2 min RAm Minute of right ascension (J2000)
38- 42 F5.2 s RAs Second of right ascension (J2000)
44 A1 --- DE- Sign of declination (J2000)
45- 46 I2 deg DEd Degree of declination (J2000)
48- 49 I2 arcmin DEm Arcminute of declination (J2000)
51- 55 F5.2 arcsec DEs Arcsecond of declination (J2000)
57- 61 F5.2 Mpc Dist [3.7/63] Distance
62 A1 --- f_Dist [a] a: distance determined from
heliocentric velocity (with H0=72km/s/Mpc)
64 A1 --- Set Sub-sample (C=complete or A=Arp sample) (2)
65 A1 --- f_Set [b] b: galaxy was not included in the
original sample
67 I1 --- Str [2/5] Interaction strength (3)
69- 71 F3.1 --- e_Str [0/0.6] Str uncertainty
73- 80 A8 --- MType Morphological classification from RC3 (VII/155)
82- 84 A3 --- Nuc Nuclear spectral activity (4)
85 A1 --- f_Nuc [cd] Flag on Nuc (5)
87- 92 F6.2 kpc Sep [4/206]? Projected separation (6)
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Note (1): Group refers to each of the interacting systems, ranging from
individual galaxies up to systems containing four individual galaxy
members. This term does not refer to defined cosmological groups.
Note (2): Spitzer Interacting Galaxies Survey (SIGS) has been selected from the
(Keel et al. 1985AJ.....90..708K 1985AJ.....90..708K) list, which identified a sample of
"interacting spiral galaxies," termed the "Complete" sample, and a
sample of more strongly interacting galaxies, referred to as
the "Arp" sample. See section 2 for further explanations.
Note (3): The interaction strength is a median value and standard deviation of
the characterization from 6 independent classifications and is
discussed in Section 2. Stages are:
2 = weakly interacting system; probably gravitationally bound, but exhibiting
low or no morphological distortions.
3 = moderately interacting system; mild morphological distortions with some
tidal features.
4 = strongly interacting system; prominent tidal features but separate nuclei
5 = mergers at the point of coalescence or merger remnants, where separate
nuclei cannot be identified on the Digitized Sky Survey (DSS) images
alone.
Note (4): The nuclear spectral activity classified based on optical spectra,
taken from K85 (Keel et al. 1985AJ.....90..708K 1985AJ.....90..708K), unless flagged.
H = HII or star-forming nuclei,
L = Low Ionization Narrow Emission Line Region (LINER),
S = Seyfert galaxy,
T = transition object that has been assumed to be a LINER/HII.
Note (5): Flag as follows:
c = Optical spectra taken from Ho et al. 1997, J/ApJS/112/315
d = Flag on L/T for NGC 5354; not explained in the paper.
Note (6): Projected separation between the galaxies in each group.
For instances where there are more than two galaxies within one system,
separations quoted are primarily between the more massive galaxies, with
separation for the less massive galaxies taken to be the nearest massive
galaxy (e.g., Grp42).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [Grp]
4- 5 I2 --- Grp [1/48] Group number, as in table1
7- 19 A13 --- Name Galaxy name
21- 25 I5 --- PID1 [32/50764] IRAC PID
27- 31 I5 --- PID2 [108/20140]? Second IRAC PID
33- 40 A8 "YYYY/MMM" Date1 Observation date for PID1
42- 58 A17 --- Date2 Observation date(s) for PID2
60- 62 I3 --- Nexp [2/338] Number of exposures
63 A1 --- --- [x]
64- 65 I2 s Exp [12/30] Exposure time of 1 exposure
67- 73 A7 --- IRACv IRAC pipeline version number
75- 80 I6 --- MPID [32/250696]? MIPS PID
82- 89 A8 "YYYY/MMM" Date MIPS observation date
91- 94 A4 --- Mode Observation mode
96-101 F6.1 s MExp [79/1772]? MIPS exposure time
103-109 A7 --- MIPSv MIPS pipeline version number
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [Grp]
4- 5 I2 --- Grp [1/48] Group number, as in table1
7- 19 A13 --- Name Galaxy name
21 A1 --- r_Name [a] Flxues from Dale et al. (7)
23- 29 F7.1 mJy F3.6 [1/10500] Spitzer/IRAC 3.6um flux
31- 35 F5.1 mJy e_F3.6 [0/300] F3.6 uncertainty (8)
37 A1 --- l_F4.5 Limit flag on F4.5 (9)
39- 44 F6.1 mJy F4.5 [0.6/6600] Spitzer/IRAC 4.5um flux
46- 50 F5.1 mJy e_F4.5 [0/200]? F4.5 uncertainty (8)
52 A1 --- l_F5.8 Limit flag on F5.8 (9)
54- 60 F7.1 mJy F5.8 [0.8/23700] Spitzer/IRAC 5.8um flux
62- 66 F5.1 mJy e_F5.8 [0/700]? F5.8 uncertainty (8)
68 A1 --- l_F8.0 Limit flag on F8.0 (9)
70- 76 F7.1 mJy F8.0 [0.8/62200] Spitzer/IRAC 8.0um flux
78- 83 F6.1 mJy e_F8.0 [0/1900]? F8.0 uncertainty (8)
85 A1 --- l_FNS Limit flag on FNS (9)
87- 93 F7.1 mJy FNS [0.4/60400] Spitzer non-stellar (NS) 8um flux
(see section 3.1)
95-100 F6.1 mJy e_FNS [0/1800]? FNS uncertainty
102 A1 --- l_F24 Limit flag on F24 (9)
104-110 F7.1 mJy F24 [1.3/93200] Spitzer/MIPS 24um flux
112-117 F6.1 mJy e_F24 [0.1/7500]? F24 uncertainty (10)
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Note (7):
a = fluxes were adopted from Dale et al. (2009, J/ApJ/703/517; also discussed
in Section 3.3).
Note (8): For IRAC photometry, 1σ uncertainty is 3%, arising from the
uncertainties in the cryogenic IRAC absolute flux calibration.
Note (9): All values with upper and lower limits are discussed in Section 3.3.
Note (10): MIPS uncertainties are 8%, again based on the absolute flux
calibration.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [Grp]
4- 5 I2 --- Grp [1/48] Group number, as in table1
7- 19 A13 --- Name Galaxy name
21- 25 F5.2 [10-7W] logL3.6 [41.2/43.8] Log of 3.6um luminosity
27 A1 --- l_logLNS Limit flag on logLNS
29- 33 F5.2 [10-7W] logLNS [40.1/44.1] Log of Non-Stellar luminosity
35 A1 --- l_logL24 Limit flag on logL24
37- 41 F5.2 [10-7W] logL24 [40.3/44.6] Log of 24um luminosity
43- 47 F5.2 [Msun] logM [8.2/11.3] Log of stellar mass (derived from
the 3.6um photometry)
49 A1 --- l_logsSFR Limit flag on logsSFR
51- 56 F6.2 [yr-1] logsSFR [-12.6/-9.1] Log of specific star formation
rate
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 10-Jul-2015