Molecular gas and dust properties of galaxies from the Great Observatories All-sky LIRG Survey

DOI: 
10.1051/0004-6361/201834088
Publication date: 
01/08/2019
Main author: 
Herrero-Illana, R.
IAA authors: 
Herrero-Illana, R.;Pérez-Torres, M. Á.;Alberdi, A.
Authors: 
Herrero-Illana, R.;Privon, G. C.;Evans, A. S.;Díaz-Santos, T.;Pérez-Torres, M. Á.;U, V.;Alberdi, A.;Iwasawa, K.;Armus, L.;Aalto, S.;Mazzarella, J.;Chu, J.;Sanders, D. B.;Barcos-Muñoz, L.;Charmandaris, V.;Linden, S. T.;Yoon, I.;Frayer, D. T.;Inami, H.;Kim, D. -C.;Borish, H. J.;Conway, J.;Murphy, E. J.;Song, Y.;Stierwalt, S.;Surace, J.
Journal: 
Astronomy and Astrophysics
Refereed: 
Yes
Publication type: 
Article
Volume: 
628
Pages: 
A71
Abstract: 
We present IRAM-30 m Telescope <SUP>12</SUP>CO and <SUP>13</SUP>CO 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 <SUP>12</SUP>CO, and 29 (52%) are also detected in <SUP>13</SUP>CO above a 3σ level. The median full width at zero intensity (FWZI) velocity of the CO line emission is 661 km s<SUP>-1</SUP>, and ̃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<SUB>2</SUB> conversion factor of ⟨α⟩ = 1.8<SUB>-0.8</SUB><SUP>+1.3</SUP> M<SUB>☉</SUB> (K km s<SUP>-1</SUP> pc<SUP>2</SUP>)<SUP>-1</SUP>; 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 <SUP>12</SUP>CO/<SUP>13</SUP>CO ratio and dust temperature, confirming a transition to elevated ratios in warmer systems. A copy of the reduced spectra is available at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr/'>http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A71'>http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/628/A71</A>
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081275599&doi=10.1051%2f0004-6361%2f201834088&partnerID=40&md5=f2d16203d14dd92d19c64a720b2a16a2
ADS Bibcode: 
2019A&A...628A..71H
Keywords: 
ISM: molecules;galaxies: ISM;galaxies: active;galaxies: starburst;radio lines: galaxies;Astrophysics - Astrophysics of Galaxies