Molecular gas and dust properties of galaxies from the Great Observatories All-sky LIRG Survey. (arXiv:1907.03854v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Herrero_Illana_R/0/1/0/all/0/1">R. Herrero-Illana</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Privon_G/0/1/0/all/0/1">G. C. Privon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Evans_A/0/1/0/all/0/1">A. S. Evans</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Diaz_Santos_T/0/1/0/all/0/1">T. D&#xed;az-Santos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Perez_Torres_M/0/1/0/all/0/1">M. &#xc1;. P&#xe9;rez-Torres</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+U_V/0/1/0/all/0/1">V. U</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alberdi_A/0/1/0/all/0/1">A. Alberdi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Iwasawa_K/0/1/0/all/0/1">K. Iwasawa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Armus_L/0/1/0/all/0/1">L. Armus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aalto_S/0/1/0/all/0/1">S. Aalto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mazzarella_J/0/1/0/all/0/1">J. Mazzarella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chu_J/0/1/0/all/0/1">J. Chu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanders_D/0/1/0/all/0/1">D. B. Sanders</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barcos_Munoz_L/0/1/0/all/0/1">L. Barcos-Mu&#xf1;oz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charmandaris_V/0/1/0/all/0/1">V. Charmandaris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Linden_S/0/1/0/all/0/1">S. T. Linden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yoon_I/0/1/0/all/0/1">I. Yoon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Frayer_D/0/1/0/all/0/1">D. T. Frayer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Inami_H/0/1/0/all/0/1">H. Inami</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kim_D/0/1/0/all/0/1">D.-C. Kim</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Borish_H/0/1/0/all/0/1">H. J. Borish</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Conway_J/0/1/0/all/0/1">J. Conway</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Murphy_E/0/1/0/all/0/1">E. J Murphy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Song_Y/0/1/0/all/0/1">Y. Song</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stierwalt_S/0/1/0/all/0/1">S. Stierwalt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Surace_J/0/1/0/all/0/1">J. Surace</a>

We present IRAM-30m Telescope $^{12}$CO and $^{13}$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 $^{12}$CO, and 29 (52%) are also detected
in $^{13}$CO above a 3$sigma$ level. The median full width at zero intensity
(FWZI) velocity of the CO line emission is 661km s$^{-1}$, and $sim$54% of the
galaxies show a multi-peak CO profile. Herschel photometric data is used to
construct the far-IR spectral energy distribution of each galaxy, which are fit
with a modified blackbody model that allows us to derive dust temperatures and
masses, and infrared luminosities. We make the assumption that the gas-to-dust
mass ratio of (U)LIRGs is comparable to local spiral galaxies with a similar
stellar mass (i.e., gas/dust of mergers is comparable to their progenitors) to
derive a CO-to-H$_2$ conversion factor of
$langlealpharangle=1.8^{+1.3}_{-0.8}M_odot$(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 1.3Gyr for local spiral galaxies. Finally, we re-examine the
relationship between the $^{12}$CO/$^{13}$CO ratio and dust temperature,
confirming a transition to elevated ratios in warmer systems.

We present IRAM-30m Telescope $^{12}$CO and $^{13}$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 $^{12}$CO, and 29 (52%) are also detected
in $^{13}$CO above a 3$sigma$ level. The median full width at zero intensity
(FWZI) velocity of the CO line emission is 661km s$^{-1}$, and $sim$54% of the
galaxies show a multi-peak CO profile. Herschel photometric data is used to
construct the far-IR spectral energy distribution of each galaxy, which are fit
with a modified blackbody model that allows us to derive dust temperatures and
masses, and infrared luminosities. We make the assumption that the gas-to-dust
mass ratio of (U)LIRGs is comparable to local spiral galaxies with a similar
stellar mass (i.e., gas/dust of mergers is comparable to their progenitors) to
derive a CO-to-H$_2$ conversion factor of
$langlealpharangle=1.8^{+1.3}_{-0.8}M_odot$(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 1.3Gyr for local spiral galaxies. Finally, we re-examine the
relationship between the $^{12}$CO/$^{13}$CO ratio and dust temperature,
confirming a transition to elevated ratios in warmer systems.

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