Herrero-Illana, R.Privon, G.C.Evans, A.S.Díaz-Santos, T.Pérez-Torres, M.Á.Uv, V.Alberdi, A.Iwasawa, KazushiArmus, 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.2025-01-312025-01-3120230004-6361https://hdl.handle.net/2445/218391We present IRAM-30 m Telescope 12CO and 13CO 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 12CO, and 29 (52%) are also detected in 13CO above a 3σ level. The median full width at zero intensity (FWZI) velocity of the CO line emission is 661 km s−1 , 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-H2 conversion factor of hαi = 1.8 +1.3 −0.8 M (K km s−1 pc2 ) −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 12CO/ 13CO ratio and dust temperature, confirming a transition to elevated ratios in warmer systems. 1 p.application/pdfeng(c) The European Southern Observatory (ESO), 2023Galàxies activesAstrofísicaGalàxiesActive galaxiesAstrophysicsGalaxiesinfo:eu-repo/semantics/article7538972025-01-31info:eu-repo/semantics/openAccess