J/A+A/607/A110 CO properties of compact group galaxies (Lisenfeld+, 2017)
The role of molecular gas in galaxy transition in compact groups.
Lisenfeld U., Alatalo K., Zucker C., Appleton P.N., Gallagher S.,
Guillard P., Johnson K.
<Astron. Astrophys. 607, A110 (2017)>
=2017A&A...607A.110L 2017A&A...607A.110L (SIMBAD/NED BibCode)
ADC_Keywords: Carbon monoxide ; Galaxies, IR ; Interstellar medium
Keywords: ISM: molecules - galaxies: interactions - galaxies: evolution -
galaxies: ISM - galaxies: star formation - galaxies: groups: general
Abstract:
Compact groups (CGs) provide an environment in which interactions
between galaxies and with the intra-group medium enable and accelerate
galaxy transitions from actively star forming to quiescent. Galaxies
in transition from active to quiescent can be selected, by their
infrared (IR) colors, as canyon or infrared transition zone (IRTZ)
galaxies. We used a sample of CG galaxies with IR data from the Wide
Field Infrared Survey Explorer (WISE) allowing us to calculate the
stellar mass and star formation rate (SFR) for each galaxy.
Furthermore, we present new CO(1-0) data for 27 galaxies and collect
data from the literature to calculate the molecular gas mass for a
total sample of 130 galaxies. This data set allows us to study the
difference in the molecular gas fraction (Mmol/Mstar) and star
formation efficiency (SFE=SFR/Mmol) between active, quiescent, and
transitioning (i.e., canyon and IRTZ) galaxies. We find that
transitioning galaxies have a mean molecular gas fraction and a mean
SFE that are significantly lower than those of actively star-forming
galaxies. The molecular gas fraction is higher than that of quiescent
galaxies, whereas the SFE is similar. These results indicate that the
transition from actively star-forming to quiescent in CG galaxies goes
along with a loss of molecular gas, possibly due to tidal forces
exerted from the neighboring galaxies or a decrease in the gas
density. In addition, the remaining molecular gas loses its ability to
form stars efficiently, possibly owing to turbulence perturbing the
gas, as seen in other, well-studied examples such as Stephan's Quintet
and HCG 57. Thus, the amount and properties of molecular gas play a
crucial role in the environmentally driven transition of galaxies from
actively star forming to quiescent.
Description:
Our sample is based on the catalog of Zucker et al. (2016, Cat.
J/ApJ/821/113), which presents WISE data for 652 galaxies in 163
compact groups, of which 428 galaxies have reliable photometry (S/N> 2
in all bands).
We searched the literature for all existing CO data for this Zucker et
al. (2016, Cat. J/ApJ/821/113) subsample (294 galaxies) and obtained
CO measurements for 102 HCG galaxies (Verdes-Montenegro et al.,
1998ApJ...497...89V 1998ApJ...497...89V; Leon et al., 1998A&A...330...37L 1998A&A...330...37L;
Martinez-Badenes et al., 2012, Cat. J/A+A/540/A96; Lisenfeld et al.,
2014, Cat. J/A+A/570/A24) and for two RSCG galaxies (Mirabel et al.,
1990A&A...236..327M 1990A&A...236..327M; Wiklind et al., 1995A&A...297..643W 1995A&A...297..643W, NGC 232 and
NGC 2831). The observations were carried out with the Institut de
Radioastronomie Millimetrique (IRAM) 30m telescope, Five College Radio
Telescope, Swedish-ESO Submillimetre Telescope (SEST), and Kitt Peak
Radio Telescope with single pointings at the central position for most
cases. To supplement the CO data for these 104 galaxies from the
literature, as part of this study we observed the redshifted CO(1-0)
line for an additional 27 galaxies.
We observed an additional 27 galaxies in CGs between January and April
2017 with the IRAM 30m telescope on Pico Veleta. We selected the
sources, based on their WISE colors, as preferentially canyon or IRTZ
objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 49 130 Molecular gas, SFR and stellar mass
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See also:
J/A+A/534/A102 : AMIGA IX. Molecular gas properties (Lisenfeld+, 2011)
J/A+A/540/A96 : Molecular gas in HCG (Martinez-Badenes+, 2012)
J/A+A/570/A24 : CO in HCG galaxies with enhanced warm H2 (Lisenfeld+, 2014)
J/ApJ/821/113 : HCG and RSCG compact group galaxies with WISE (Zucker+, 2016)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Name of the galaxy
15- 19 F5.1 Mpc Dist Distance (based on H0=70km/s/Mpc)
21 A1 --- l_logMmol0 Upper limit code for logMmol0 (2)
23- 27 F5.2 [Msun] logMmol0 Decimal logarithm of the molecular gas mass
in the central pointing
29 A1 --- l_logMmol Upper limit code for logMmol (2)
31- 35 F5.2 [Msun] logMmol Decimal logarithm of the molecular gas mass
extrapolated to the entire disk
37 I1 --- Ref Reference code for the CO measurement from
which Mmol is calculated (1)
39- 43 F5.2 Msun/yr SFR Star formation rate
45- 49 F5.2 [Msun] logMstar Decimal logarithm of the stellar mass
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Note (1): Reference codes for the CO measurement from which Mmol is calculated
as follows:
1 = This paper.
2 = Lisenfeld et al. (2014, Cat. J/A+A/534/A102)
3 = Martinez-Badenes et al. (2012, Cat. J/A+A/540/A96)
4 = Leon et al. (1998A&A...330...37L 1998A&A...330...37L)
5 = Verdes-Montenegro et al. (2001A&A...377..812V 2001A&A...377..812V)
6 = Wiklind et al. (1995A&A...297..643W 1995A&A...297..643W)
7 = Mirabel et al. (1990A&A...236..327M 1990A&A...236..327M)
Note (2): Upper limit code for logMol0 and logMol:
< for upper limit, else detection
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Acknowledgements:
Ute Lisenfeld, ute(at)ugr.es
(End) Ute Lisenfeld [Universidad Granada], Patricia Vannier [CDS] 04-Sep-2017