VALES VI: ISM enrichment in star-forming galaxies up to z similar to 0.2 using (CO)-C-12(1-0), (CO)-C-13(1-0), and (CO)-O-18(1-0) line luminosity ratios
Journal article, 2020

We present Atacama Large Millimeter/sub-millimeter Array (ALMA) observations towards 27 low-redshift (0.02< z< 0.2) starforming galaxies taken from the Valpara ' iso ALMA/APEX Line Emission Survey. We perform stacking analyses of the (CO)-C-12(1-0), (CO)-C-13(1-0), and (CO)-O-18(1-0) emission lines to explore the L' [(CO)-C-12(1-0)]/L' [(CO)-C-13(1-0)] [hereafter L' ((CO)-C-12)/L' ((CO)-C-13)] and L' [(CO)-C-13(1-0)]/L' [(CO)-O-18(1-0)] [hereafter L' ((CO)-C-13)/L' ((CO)-O-18)] line luminosity ratio dependence as a function of different global galaxy parameters related to the star formation activity. The sample has far-IR luminosities of 1010.1-11.9 L and stellar masses of 109.8-10.9M(circle dot) corresponding to typical star-forming and starburst galaxies at these redshifts. On average, we find an L' (12CO)/L' ((CO)-C-13) line luminosity ratio value of 16.1 +/- 2.5. Galaxies with pieces of evidence of possible merging activity tend to show higher L' ((CO)-C-12)/L' (13CO) ratios by a factor of 2, while variations of this order are also found in galaxy samples with higher star formation rates (SFRs) or star formation efficiencies (SFEs). We also find an average L' ((CO)-C-13)/L' ((CO)-O-18) line luminosity ratio of 2.5 +/- 0.6, which is in good agreement with those previously reported for starburst galaxies. We find that galaxy samples with high LIR, SFR, and SFE show low L' ((CO)-C-13)/L' ((CO)-O-18) line luminosity ratios with high L' ((CO)-C-12)/L' ((CO)-C-13) line luminosity ratios, suggesting that these trends are produced by selective enrichment of massive stars in young starbursts.

techniques: interferometric

methods: statistical

galaxies: ISM

galaxies: star formation


H. Mendez-Hernandez

University of Valparaíso

E. Ibar

University of Valparaíso

Kirsten Kraiberg Knudsen

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

P. Cassata

Osservatorio Astronomico di Padova

University of Padua

M. Aravena

Diego Portales University

M. J. Michalowski

Adam Mickiewicz University in PoznaƄ

Zhi-Yu Zhang

Nanjing University

M. A. Lara-Lopez

University of Copenhagen

R. J. Ivison

European Southern Observatory Santiago

P. van der Werf

Leiden University

V. Villanueva

University of Maryland

R. Herrera-Camus

University of Concepcion

T. M. Hughes

University of Valparaíso

University of Science and Technology of China

China Chile Joint Ctr Astron

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 497 3 2771-2785

Subject Categories

Analytical Chemistry

Astronomy, Astrophysics and Cosmology

Environmental Sciences



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