TY - JOUR
T1 - Observations of neutral carbon in 29 high-z lensed dusty star-forming galaxies and the comparison of gas mass tracers
AU - Gururajan, G.
AU - B'ethermin, M.
AU - Sulzenauer, N.
AU - Theule, P.
AU - Spilker, J. S.
AU - Aravena, M.
AU - Chapman, S. C.
AU - Gonzalez, A.
AU - Greve, T. R.
AU - Narayanan, D.
AU - Reuter, C.
AU - Vieira, J. D.
AU - Weiss, A.
PY - 2023
Y1 - 2023
N2 - Context. The nature and evolution of high-redshift dusty star-forming galaxies (high-z
DSFGs) remain open questions. Their massive gas reservoirs play an
important role in driving the intense star formation rates hosted in
these galaxies.
Aims. Our aim is to estimate the molecular gas content of high-z
DSFGs by using various gas mass tracers, such as the [CI], CO, [CII]
emission lines and the dust content. These tracers need to be well
calibrated as they are all limited by uncertainties on factors such as αCO, XCI, α[CII], and δGDR,
thereby affecting the accurate determination of the gas mass. The main
goal of our work is to check the consistency between the gas mass
tracers and to cross-calibrate the uncertain factors.
Methods. We observed the two [CI] line transitions for 29
South Pole telescope Submillimeter Galaxies (SPT-SMGs) with the Atacama
Large Millimeter/submillimeter Array–Atacama Compact Array (ALMA-ACA).
Additionally, we also present new Atacama Pathfinder EXperiment (APEX)
observations of [CII] line for nine of these galaxies. We combined our
observations with the rich ancillary data of low- and mid-J CO lines, ancillary [CII] line, and dust mass estimations for these galaxies.
Results. We find a nearly linear relation between the infrared
luminosity and [CI] luminosity if we fit the starbursts and
main-sequence galaxies separately. We measure a median [CI]-derived
excitation temperature of 34.5 ± 2.1 K. We probed the properties of the
interstellar medium (ISM), such as density and radiation field
intensity, using [CI] to mid- or high-J CO lines and the
[CI]-to-infrared luminosity ratio, and find similar values to the SMG
populations in the literature. Finally, the gas masses estimated from
[CI], CO, dust, and [CII] do not exhibit any significant trend with the
infrared luminosity or the dust temperature. We provide the various
cross-calibrations between these tracers.
Conclusions. Our study confirms that [CI] is a suitable tracer
of the molecular gas content, and shows an overall agreement between
all the classical gas tracers used at high redshift. However, their
absolute calibration, and thus the gas depletion timescale measurements,
remain uncertain.
AB - Context. The nature and evolution of high-redshift dusty star-forming galaxies (high-z
DSFGs) remain open questions. Their massive gas reservoirs play an
important role in driving the intense star formation rates hosted in
these galaxies.
Aims. Our aim is to estimate the molecular gas content of high-z
DSFGs by using various gas mass tracers, such as the [CI], CO, [CII]
emission lines and the dust content. These tracers need to be well
calibrated as they are all limited by uncertainties on factors such as αCO, XCI, α[CII], and δGDR,
thereby affecting the accurate determination of the gas mass. The main
goal of our work is to check the consistency between the gas mass
tracers and to cross-calibrate the uncertain factors.
Methods. We observed the two [CI] line transitions for 29
South Pole telescope Submillimeter Galaxies (SPT-SMGs) with the Atacama
Large Millimeter/submillimeter Array–Atacama Compact Array (ALMA-ACA).
Additionally, we also present new Atacama Pathfinder EXperiment (APEX)
observations of [CII] line for nine of these galaxies. We combined our
observations with the rich ancillary data of low- and mid-J CO lines, ancillary [CII] line, and dust mass estimations for these galaxies.
Results. We find a nearly linear relation between the infrared
luminosity and [CI] luminosity if we fit the starbursts and
main-sequence galaxies separately. We measure a median [CI]-derived
excitation temperature of 34.5 ± 2.1 K. We probed the properties of the
interstellar medium (ISM), such as density and radiation field
intensity, using [CI] to mid- or high-J CO lines and the
[CI]-to-infrared luminosity ratio, and find similar values to the SMG
populations in the literature. Finally, the gas masses estimated from
[CI], CO, dust, and [CII] do not exhibit any significant trend with the
infrared luminosity or the dust temperature. We provide the various
cross-calibrations between these tracers.
Conclusions. Our study confirms that [CI] is a suitable tracer
of the molecular gas content, and shows an overall agreement between
all the classical gas tracers used at high redshift. However, their
absolute calibration, and thus the gas depletion timescale measurements,
remain uncertain.
KW - Galaxies: high-redshift
KW - Galaxies: evolution
KW - Galaxies: ISM
KW - Galaxies: star formation
KW - Submillimeter: galaxies
U2 - 10.1051/0004-6361/202346449
DO - 10.1051/0004-6361/202346449
M3 - Journal article
SN - 0004-6361
VL - 676
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A89
ER -