J/MNRAS/476/875 xGASS catalog (Catinella+, 2018)
xGASS: total cold gas scaling relations and molecular-to-atomic gas ratios of
galaxies in the local Universe.
Catinella B., Saintonge A., Janowiecki S., Cortese L., Dave R.,
Lemonias J.J., Cooper A.P., Schiminovich D., Hummels C.B., Fabello S.,
Gereb K., Kilborn V., Wang J.
<Mon. Not. R. Astron. Soc., 476, 875-895 (2018)>
=2018MNRAS.476..875C 2018MNRAS.476..875C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; H I data
Keywords: galaxies: evolution - galaxies: fundamental parameters -
galaxies: ISM - radio lines: galaxies
Abstract:
We present the extended GALEX Arecibo SDSS Survey (xGASS), a gas
fraction-limited census of the atomic hydrogen (HI) gas content of
1179 galaxies selected only by stellar mass (M*=109-1011.5M☉)
and redshift (0.01<z<0.05). This includes new Arecibo observations
of 208 galaxies, for which we release catalogues and HI spectra. In
addition to extending the GASS HI scaling relations by one decade
in stellar mass, we quantify total (atomic+molecular) cold gas
fractions and molecular-to-atomic gas mass ratios, Rmol, for the
subset of 477 galaxies observed with the IRAM 30m telescope. We find
that atomic gas fractions keep increasing with decreasing stellar
mass, with no sign of a plateau down to logM*/M☉=9. Total gas
reservoirs remain HI-dominated across our full stellar mass range,
hence total gas fraction scaling relations closely resemble atomic
ones, but with a scatter that strongly correlates with Rmol,
especially at fixed specific star formation rate. On average, Rmol
weakly increases with stellar mass and stellar surface density µ*,
but individual values vary by almost two orders of magnitude at fixed
M* or µ*. We show that, for galaxies on the star-forming
sequence, variations of Rmol are mostly driven by changes of the HI
reservoirs, with a clear dependence on µ*. Establishing if galaxy
mass or structure plays the most important role in regulating the cold
gas content of galaxies requires an accurate separation of bulge and
disc components for the study of gas scaling relations
Description:
We presented xGASS, the culmination of several years of effort to
gather deep HI observations for a stellar mass-selected sample of
∼1200 galaxies with homogeneously measured optical and SF properties.
xGASS is the combination of the original GASS survey, which started in
2008 and targeted galaxies with stellar masses larger than
1010M☉, and its extension to M*=109M☉. Together, these
surveys required ∼1300h of Arecibo telescope time. Our unique approach
of carrying out gas fraction-limited observations down to MHI/M*∼2 per
cent allowed us to obtain stringent upper limits, which are essential
to interpret variations of gas content as a function of galaxy
properties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 105 208 SDSS and UV parameters of GASS-low galaxies
tablea2.dat 96 120 HI Properties of GASS-low detections
tablea3.dat 54 88 GASS-low non-detections
notes.dat 80 235 Individual notes
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See also:
J/ApJS/233/22 : xCOLD GASS catalog (Saintonge+, 2017)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- GASS GASS identifier
8- 26 A19 --- SDSS SDSS identifier
28- 38 A11 --- OName Other name
40- 45 F6.4 --- zSDSS SDSS redshift
47- 51 F5.2 [Msun] logM* log10 Stellar mass
53- 57 F5.2 arcsec R50z Radius containing 50 per cent of the
Petrosian flux in z band
59- 63 F5.2 arcsec R50r Radius containing 50 per cent of the
Petrosian flux in r band
65- 69 F5.2 arcsec R90r Radius containing 90 per cent of the
Petrosian flux in r band
71- 74 F4.2 [Msun/kpc+2] logSuBr log10 stellar mass surface density
76- 79 F4.2 mag extr Galactic extinction in r band from SDSS
81- 85 F5.2 mag rmag r-band model magnitude from SDSS,
corrected for Galactic extinction
87- 91 F5.3 --- (b/a)r Minor-to-major axial ratio from the
exponential fit in r band, from SDSS
93- 94 I2 deg incl Inclination to the line of sight
96- 99 F4.2 mag NUV-r ?=- NUV-r observed colour, corrected for
Galactic extinction
101-105 F5.3 Msun/yr SFR ?=- Star formation rate from NUV and WISE
photometry
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- GASS GASS identifier
8- 26 A19 --- SDSS SDSS identifier
28- 33 F6.4 --- zSDSS SDSS redshift
35- 36 I2 min Ton On-source integration time of the
Arecibo observation
38- 39 I2 km/s DV Velocity resolution of the final,
smoothed spectrum, {DELTA}V
41- 48 F8.6 --- z Redshift measured from the HI spectrum
50- 52 I3 km/s W50 Observed velocity width of the source line
profile, measured at the 50 per cent level
of each peak
54- 55 I2 km/s e_W50 rms uncertainty on W50
57- 59 I3 km/s W50c Velocity width corrected for instrumental
broadening and cosmological redshift only
61- 65 F5.2 Jy.km/s FHI Integrated HI-line flux density
67- 70 F4.2 Jy.km/s e_FHI rms uncertainty on FHI
72- 75 F4.2 mJy rms rms noise of the observation
77- 81 F5.1 --- S/N Signal-to-noise ratio of the HI spectrum
83- 87 F5.2 [Msun] logMHI log10 HI mass
89- 93 F5.2 [-] logMHI/M* log10 HI mass fraction
95 I1 --- q [1/5] Quality flag (1)
96 A1 --- Note [*] * indicates a note in notes.dat file
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Note (1): Quality flag as follows:
1 = good
2 = marginal
5 = confused
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- GASS GASS identifier
8- 26 A19 --- SDSS SDSS identifier
28- 33 F6.4 --- zSDSS SDSS redshift
35- 36 I2 min Ton On-source integration time of the
Arecibo observation
38- 41 F4.2 mJy rms rms noise of the observation
43- 46 F4.2 [Msun] logMHIlim upper limit on the HI mass
48- 52 F5.2 [-] logMHIlim/M* upper limit on the gas fraction
54 A1 --- Note [*] * indicates a note in notes.dat file
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- GASS GASS identifier
8- 80 A73 --- Note Note
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 19-Feb-2021