Molecular gas and dust properties of galaxies from the Great Observatories All-sky LIRG Survey
Journal article, 2019
We present IRAM-30 m Telescope (CO)-C-12 and (CO)-C-13 observations of a sample of 55 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in the local universe. This sample is a subset of the Great Observatory All-Sky LIRG Survey (GOALS), for which we use ancillary multi-wavelength data to better understand their interstellar medium and star formation properties. Fifty-three (96%) of the galaxies are detected in (CO)-C-12, and 29 (52%) are also detected in (CO)-C-13 above a 3 sigma level. The median full width at zero intensity (FWZI) velocity of the CO line emission is 661 km s(-1), and similar to 54% of the galaxies show a multi-peak CO profile. Herschel photometric data is used to construct the far-IR spectral energy distribution of each galaxy, which are fit with a modified blackbody model that allows us to derive dust temperatures and masses, and infrared luminosities. We make the assumption that the gas-to-dust mass ratio of (U)LIRGs is comparable to local spiral galaxies with a similar stellar mass (i.e., gas/dust of mergers is comparable to their progenitors) to derive a CO-to-H-2 conversion factor of = 1.8(-0.8)(+1.3) M-circle dot (K km s(-1) pc(2))(-1); such a value is comparable to that derived for (U)LIRGs based on dynamical mass arguments. We derive gas depletion times of 400 600 Myr for the (U)LIRGs, compared to the 1.3 Gyr for local spiral galaxies. Finally, we re-examine the relationship between the (CO)-C-12/(CO)-C-13 ratio and dust temperature, confirming a transition to elevated ratios in warmer systems.
galaxies: starburst
ISM: molecules
galaxies: ISM
radio lines: galaxies
galaxies: active
Author
R. Herrero-Illana
European Southern Observatory (ESO)
Spanish National Research Council (CSIC)
G. C. Privon
University of Florida
Pontificia Universidad Catolica de Chile
A. S. Evans
University of Virginia
National Radio Astronomy Observatory
T. Diaz-Santos
Diego Portales University
M. A. Perez-Torres
University of Zaragoza
Spanish National Research Council (CSIC)
A. Alberdi
Spanish National Research Council (CSIC)
K. Iwasawa
University of Barcelona
L. Armus
California Institute of Technology (Caltech)
Susanne Aalto
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
J. Mazzarella
California Institute of Technology (Caltech)
J. Chu
Gemini Observatory North
D. B. Sanders
Atacama Large Millimeter-submillimeter Array (ALMA)
University of Hawaii
L. Barcos-Munoz
University of Virginia
National Radio Astronomy Observatory
V Charmandaris
National Observatory of Athens
S. T. Linden
University of Virginia
I Yoon
National Radio Astronomy Observatory
D. T. Frayer
Green Bank Observatory
H. Inami
NOAA, 950 North Cherry Ave
D-C Kim
National Radio Astronomy Observatory
H. J. Borish
University of Virginia
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
E. J. Murphy
California Institute of Technology (Caltech)
National Radio Astronomy Observatory
Y. Song
University of Virginia
S. Stierwalt
California Institute of Technology (Caltech)
J. Surace
California Institute of Technology (Caltech)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 628 A71Subject Categories
Analytical Chemistry
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.1051/0004-6361/201834088