Resolved CO(1-0) emission and gas properties in luminous dusty star forming galaxies at z=2-4

Abstract

We present the results of a survey of CO(1-0) emission in 14 infrared luminous dusty star forming galaxies (DSFGs) at 2 < z < 4 with the NSF's Karl G. Jansky Very Large Array. All sources are detected in CO(1-0), with an ~1arcsec angular resolution. Seven sources show extended and complex structure. We measure CO luminosities of $(\mu )L_{CO(1-0)}^{\prime }=0.4-2.9x10^{11}$ K km s${}^{-1}$ pc${}^2$, and molecular gas masses of ($\mu$)M${}_{H2}$ = 1.3 - 8.6 x 10${}^{11}$ Mo, where (μ) is the magnification factor. The derived molecular gas depletion times of t${}_{\mathrm{dep}}$ = 40 - 460 Myr, cover the expected range of both normal star forming galaxies and starbursts. Comparing to the higher-J CO transitions previously observed for the same sources, we find CO temperature brightness ratios of r${}_{32/10}$ = 0.4 - 1.4, r${}_{43/10}$ = 0.4 - 1.7, and r${}_{54/10}$ = 0.3 - 1.3. We find a wide range of CO spectral line energy distributions (SLEDs), in agreement with other high-z DSFGs, with the exception of three sources that are most comparable to the Cloverleaf and APM08279+5255. Based on radiative transfer modelling of the CO SLEDs we determine densities of n${}_{H2}$ = 0.3 - 8.5 x 10${}^3$ cm${}^{-3}$ and temperatures of T${}_K$ = 100 - 200 K. Lastly, four sources are detected in the continuum, three have radio emission consistent with their infrared derived star formation rates, while HerBS-70E requires an additional synchrotron radiation component from an active galactic nucleus. Overall, we find that even though the sample is similarly luminous in the infrared, by tracing the CO(1-0) emission a diversity of galaxy and excitation properties are revealed, demonstrating the importance of CO(1-0) observations in combination to higher-J transitions.

25pages , 13 figures, Accepted for publication at ApJ

References in corpus (38)

• Cosmic Star Formation History
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Combined CO & Dust Scaling Relations of Depletion Time and Molecular Gas Fractions with Cosmic Time, Specific Star Formation Rate and Stellar Mass
• A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34
• The Detection of a Population of Submillimeter-Bright, Strongly-Lensed Galaxies
• Highly-excited CO emission in APM08279+5255 at z=3.9
• The Herschel-ATLAS Data Release 1 Paper I: Maps, Catalogues and Number Counts
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• The Evolution of the IR Luminosity Function and Dust-obscured Star Formation in the Last 13 Billion Years
• CO(1-0) in z >/~ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs
• LOFAR/H-ATLAS: A deep low-frequency survey of the Herschel-ATLAS North Galactic Pole field
• The ALMA Spectroscopic Survey Large Program: The Infrared Excess of z=1.5-10 UV-selected Galaxies and the Implied High-Redshift Star Formation History
• The Herschel-ATLAS: a sample of 500μm-selected lensed galaxies over 600 square degrees
• The Rest-Frame Submillimeter Spectrum of High-Redshift, Dusty, Star-Forming Galaxies
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: Spectroscopic redshifts
• Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z~2-4 as probed by multi-J CO lines
• Imaging the Molecular Gas in a z=3.9 Quasar Host Galaxy at 0.3" Resolution: A Central, Sub-Kiloparsec Scale Star Formation Reservoir in APM 08279+5255
• Turbulent Gas in Lensed Planck-selected Starbursts at redshifts 1-3.5
• Dust, CO and [CI]: Cross-calibration of molecular gas mass tracers in metal-rich galaxies across cosmic time
• Evolution of cosmic star formation in the SCUBA-2 Cosmology Legacy Survey
• CO(1-0) line imaging of massive star-forming disc galaxies at z=1.5-2.2
• The most distant, luminous, dusty star-forming galaxies: redshifts from NOEMA and ALMA spectral scans
• Deep CO(1-0) Observations of z=1.62 Cluster Galaxies with Substantial Molecular Gas Reservoirs and Normal Star Formation Efficiencies
• Confirming Herschel candidate protoclusters from ALMA/VLA CO observations
• CO emission in distant galaxies on and above the main sequence
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
• The Herschel Bright Sources (HerBS): Sample definition and SCUBA-2 observations
• VLA imaging of 12CO J=1-0 and free-free emission in lensed submillimetre galaxies
• NOEMA redshift measurements of bright Herschel galaxies
• COALAS: I. ATCA CO(1-0) survey and luminosity function in the Spiderweb protocluster at z=2.16
• VALES: I. The molecular gas content in star-forming dusty H-ATLAS galaxies up to z=0.35
• Dust continuum, CO, and [C I] 1-0 lines: self-consistent H2 mass estimates and the possibility of globally CO-dark galaxies at $z=0.35$
• Close-up view of a luminous star-forming galaxy at z=2.95
• A High-Resolution Investigation of the Multi-Phase ISM in a Galaxy during the First Two Billion Years
• The Bright Extragalactic ALMA Redshift Survey (BEARS) I: redshifts of bright gravitationally-lensed galaxies from the Herschel ATLAS
• A search for the lenses in the Herschel Bright Sources (HerBS) Sample
• IRAM 30m-EMIR Redshift Search of z = 3-4 Lensed Dusty Starbursts selected from the HerBS sample
• Cold Molecular Gas and Free-Free Emission from Hot, Dust-Obscured Galaxies at $z$~3

Cited by in corpus (8)

• z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [I] Overview
• z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [III] Physical properties
• CO(1--0) imaging reveals 10-kiloparsec molecular gas reservoirs around star-forming galaxies at high redshift
• PRUSSIC III -- ALMA and NOEMA survey of dense gas in high-redshift star-forming galaxies
• Vz-GAL: Probing Cold Molecular Gas in Dusty Star-forming Galaxies at z=1-6
• Estimating the evolution and the content fractions of baryonic gas for Luminous Infrared Galaxies
• HerS-3: An Exceptional Einstein Cross Reveals a Massive Dark Matter Halo
• Predicting the resolved CO emission of $z=1-3$ star-forming galaxies