J/A+A/678/A28 z-GAL. III. Physical properties (Berta+, 2023)
z-GAL: A NOEMA spectroscopic redshift survey of bright Herschel galaxies.
III. Physical properties.
Berta S., Stanley F., Ismail D., Cox P., Neri R., Yang C., Young A.J.,
Jin S., Dannerbauer H., Bakx T.J.L.C., Beelen A., Weiss A., Nanni A.,
Omont A., Van Der Werf P., Krips M., Baker A.J., Bendo G., Borsato E.,
Buat V., Butler K.M., Chartab N., Cooray A., Dye S., Eales S., Gavazzi R.,
Hughes D., Ivison R.J., Jones B.M., Lehnert M., Marchetti L., Messias H.,
Negrello M., Perez-fournon I., Riechers D.A., Serjeant S., Urquhart S.,
Vlahakis C.
<Astron. Astrophys., 678, A28 (2023)>
=2023A&A...678A..28B 2023A&A...678A..28B (SIMBAD/NED BibCode)
ADC_Keywords: Millimetric/submm sources ; Galaxies, IR ; Redshifts ;
Photometry, millimetric/submm
Keywords: submillimeter: galaxies - galaxies: high-redshift -
galaxies: starburst - galaxies: star formation -
galaxies: statistics - galaxies: ISM
Abstract:
The z-GAL survey observed 137 bright Herschel-selected targets with
the IRAM Northern Extended Millimeter Array, with the aim to measure
their redshift and study their properties. Several of them have been
resolved into multiple sources. Consequently, robust spectroscopic
redshifts have been measured for 165 individual galaxies in the range
0.8<z<6.5. In this paper we analyse the millimetre spectra of the
z-GAL sources, using both their continuum and line emission to derive
their physical properties. At least two spectral lines are detected
for each source, including transitions of 12CO, [CI], and H2O. The
observed 12CO line ratios and spectral line energy distributions of
individual sources resemble those of local starbursts. In seven
sources the para-H2O (211-202) transition is detected and
follows the IR versus H2O luminosity relation of sub-millimetre
galaxies. The molecular gas mass of the z-GAL sources is derived from
their 12CO, [CI], and sub-millimetre dust continuum emission. The
three tracers lead to consistent results, with the dust continuum
showing the largest scatter when compared to 12CO. The gas-to-dust
mass ratio of these sources was computed by combining the information
derived from 12CO and the dust continuum and has a median value of
107, similar to star-forming galaxies of near-solar metallicity. The
same combined analysis leads to depletion timescales in the range
between 0.1 and 1.0Gyr, which place the z-GAL sources between the
'main sequence' of star formation and the locus of starbursts.
Finally, we derived a first estimate of stellar masses - modulo
possible gravitational magnification - by inverting known gas scaling
relations: the z-GAL sample is confirmed to be mostly composed by
starbursts, whereas ∼25% of its members lie on the main sequence of
star-forming galaxies (within ±0.5dex).
Description:
We presented a detailed analysis of the z-GAL sample, based on NOEMA
millimetre observations of both dust continuum and lines emission, and
comprising 165 individual sources with robust spectroscopic redshift
(Paper I, Cox et al., 2023A&A...678A..26C 2023A&A...678A..26C, Cat. J/A+A/678/A26 and Neri
et al., 2020A&A...635A...7N 2020A&A...635A...7N, Cat. J/A+A/635/A7). The detected spectral
emission lines include 12CO, H2O, and [CI] transitions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 101 177 Values of L'12CO of all detected transitions
of the z-GAL sources
tableb2.dat 136 177 *Derived physical properties of the z-GAL sources
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Note on tableb2.dat: Dust modelling has been performed only for single sources
or secure lensed multiples, therefore for all other cases several columns
are not filled.
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See also:
J/A+A/678/A26 : z-GAL. I. Overview (Cox+, 2023)www
J/A+A/678/A27 : z-GAL. II. Dust continuum properties (Ismail+, 2023)
Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Source Source name
19- 24 F6.4 --- z ?=- Redshift
26- 30 F5.2 10+10K.km/s/pc2 muL(12CO(2-1)) ?=- Line luninosity of
12CO(2-1)
32- 35 F4.2 10+10K.km/s/pc2 e_muL(12CO(2-1)) ? Line luninosity of
12CO(2-1) error
37- 41 F5.2 10+10K.km/s/pc2 muL(12CO(3-2)) ?=- Line luninosity of
12CO(3-2)
43- 46 F4.2 10+10K.km/s/pc2 e_muL(12CO(3-2)) ? Line luninosity of
12CO(3-2) error
48- 52 F5.2 10+10K.km/s/pc2 muL(12CO(4-3)) ?=- Line luninosity of
12CO(4-3)
54- 57 F4.2 10+10K.km/s/pc2 e_muL(12CO(4-3)) ? Line luninosity of
12CO(4-3) error
59- 63 F5.2 10+10K.km/s/pc2 muL(12CO(5-4)) ?=- Line luninosity of
12CO(5-4)
65- 68 F4.2 10+10K.km/s/pc2 e_muL(12CO(5-4)) ? Line luninosity of
12CO(5-4) error
70- 74 F5.2 10+10K.km/s/pc2 muL(12CO(6-5)) ?=- Line luninosity of
12CO(6-5)
76- 79 F4.2 10+10K.km/s/pc2 e_muL(12CO(6-5)) ? Line luninosity of
12CO(6-5) error
82- 85 F4.2 10+10K.km/s/pc2 muL(12CO(7-6)) ?=- Line luninosity of
12CO(7-6)
87- 90 F4.2 10+10K.km/s/pc2 e_muL(12CO(7-6)) ? Line luninosity of
12CO(7-6) error
93- 96 F4.2 10+10K.km/s/pc2 muL(12CO(8-7)) ?=- Line luninosity of
12CO(8-7)
98-101 F4.2 10+10K.km/s/pc2 e_muL(12CO(8-7)) ? Line luninosity of
12CO(8-7) error
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Source Source name
19- 21 A3 --- Trans Lowest CO transition
23- 27 F5.2 10+10K/km/s/pc2 muL(12CO(1-0)) ?=- Line luninosity of
12CO(1-0)
29- 33 F5.2 10+10K/km/s/pc2 e_muL(12CO(1-0)) ? Line luninosity of
12CO(1-0) error
35- 39 F5.2 10+11Msun muMmol12CO ?=- Molecular gas mass
from 12CO
41- 45 F5.2 10+11Msun e_muMmol12CO ? Molecular gas mass
from 12CO error
47- 51 F5.2 10+11Msun muMmol850um ?=- Molecular gas mass
from 850um continuum
53- 56 F4.2 10+11Msun e_muMmol850um ? Molecular gas mass
from 850um continuum error
58- 63 F6.2 --- deltaGDR ?=- Gas-to-dust mass ratio
from 12CO conversion factor
65- 70 F6.2 --- e_deltaGDR ? Gas-to-dust mass ratio from
12CO conversion factor error
72- 77 F6.2 10+11Lsun muLIR ?=- IR luminosity
79- 83 F5.2 10+11Lsun e_muLIR ? IR luminosity error
85- 91 F7.2 Msun/yr muSFR ?=- Star formation rate
93- 98 F6.2 Msun/yr e_muSFR ? Star formation rate error
100-103 F4.2 10+9yr taudep ?=- Depletion timescale from
12CO conversion factor
105-108 F4.2 10+9yr e_taudep ? Depletion timescale from
12CO conversion factor error
110-114 F5.2 10+11Msun muEM* ?=- µEM* value (1)
116-120 F5.2 10+11Msun e_muEM* ? µEM* value error
122-125 F4.2 --- E ?=- Extra term ,
E=C/(C(0.84+0,026t)-D
127-131 F5.2 [-] Dlog(MS) ?=- Distance of each z-GAL
galaxy from the MS,
log(muSFR/SFR(MS))
133-136 F4.2 [-] e_Dlog(MS) ? Distance of each z-GAL galaxy
from the MS error
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Note (1): where µ is the lens magnification, E=C/(C(0.84+0,026t)-D, and
M* is the stellar mass.
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History:
From electronic version of the journal
References:
Cox et al., Paper I 2023A&A...678A..26C 2023A&A...678A..26C, Cat. J/A+A/678/A26
Ismail et al., Paper II 2023A&A...678A..27I 2023A&A...678A..27I, Cat. J/A+A/678/A27
(End) Patricia Vannier [CDS] 30-Nov-2023