z -GAL: A NOEMA spectroscopic redshift survey of bright Herschel galaxies: III. Physical properties
Journal article, 2023
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 1.0 Gyr, 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 ±0.5 dex).
Galaxies: ISM
Galaxies: high-redshift
Galaxies: star formation
Submillimeter: galaxies
Galaxies: statistics
Galaxies: starburst
Author
S. Berta
Institut de Radioastronomie Millimétrique (IRAM)
F. Stanley
Institut de Radioastronomie Millimétrique (IRAM)
D. Ismail
Laboratoire d'Astrophysique de Marseille
P. Cox
Institut d 'Astrophysique de Paris
R. Neri
Institut de Radioastronomie Millimétrique (IRAM)
Chentao Yang
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. J. Young
Rutgers University
S. Jin
Technical University of Denmark (DTU)
Cosmic Dawn Center (DAWN)
H. Dannerbauer
Instituto de Astrofísica de Canarias
University of La Laguna
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
National Astronomical Observatory of Japan
Nagoya University
A. Beelen
Laboratoire d'Astrophysique de Marseille
A. Weiß
Max Planck Society
A. Nanni
Istituto nazionale di astrofisica (INAF)
Narodowe Centrum Badan Jadrowych
A.A. Omont
Institut d 'Astrophysique de Paris
P. van der Werf
Leiden University
M. Krips
Institut de Radioastronomie Millimétrique (IRAM)
A. J. Baker
Rutgers University
University of the Western Cape
G. J. Bendo
University of Manchester
E. Borsato
University of Padua
V. Buat
Laboratoire d'Astrophysique de Marseille
K. M. Butler
Institut de Radioastronomie Millimétrique (IRAM)
N. Chartab
University of California
A. Cooray
University of California
S. Dye
University of Nottingham
S. Eales
Cardiff University
R. Gavazzi
Institut d 'Astrophysique de Paris
D. Hughes
National Institute of Astrophysics, Optics and Electronics
R. J. Ivison
Macquarie University
Dublin Institute for Advanced Studies
European Southern Observatory (ESO)
University of Edinburgh
B. M. Jones
University of Cologne
M. Lehnert
CRAL Le Centre de Recherche Astronomique de Lyon
L. Marchetti
Istituto di Radioastronomia
University of Cape Town
H. Messias
European Southern Observatory Santiago
Atacama Large Millimeter-submillimeter Array (ALMA)
M. Negrello
Cardiff University
I. Perez-Fournon
University of La Laguna
Instituto de Astrofísica de Canarias
D. A. Riechers
University of Cologne
S. Serjeant
Open University
S. Urquhart
Open University
C. Vlahakis
National Radio Astronomy Observatory
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 678 A28Exploring the Hidden Dusty Nuclei of Galaxies (HIDDeN)
European Research Council (ERC) (789410), 2018-10-01 -- 2023-09-30.
Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/202346803