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We present single-dish (sub)millimeter observations of gas and dust in the Galactic high-mass star-forming region G19.61-0.23, with the aim of studying the large-scale properties and physical conditions of the molecular gas across the…

We study the Carbon Monoxide (CO) excitation, mean molecular gas density and interstellar radiation field (ISRF) intensity in a comprehensive sample of 76 galaxies from local to high redshift (z~0-6), selected based on detections of their…

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

Astrophysics of Galaxies · Physics 2015-06-16 Paul F. Goldsmith

We present fully-sampled maps of 461 GHz CO (4-3), 807 GHz CO (7-6), and 492 GHz [CI] (3P1-3P0) emission from the inner 3 degrees of the Galactic Center region taken with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)…

Aims: Our aims are threefold: a) To compare the $uv$ and mm-wave results; b) to interpret 13CO and 12CO abundances in terms of the physical processes which separately and jointly determine them; c) to interpret observed J=1-0 rotational…

Astrophysics · Physics 2009-11-13 H. S. Liszt

We performed a molecular line survey of 82 high-mass protostellar objects in search for inflow signatures associated with high-mass star formation. Using the H$^{13}$CO$^+$ (1$-$0) line as an optically thin tracer, we detected a…

Astrophysics of Galaxies · Physics 2018-05-17 Hyunju Yoo , Kee-Tae Kim , Jungyeon Cho , Minho Choi , Jingwen Wu , Neal J. Evans , L. M. Ziurys

Aims: We derive the probability density functions (PDFs) of column density for a complete sample of prominent molecular cloud complexes closer than 200 pc. Methods: We derive near-infrared dust extinction maps for 23 molecular cloud…

Astrophysics of Galaxies · Physics 2015-05-14 J. Kainulainen , H. Beuther , T. Henning , R. Plume

Dense gas is important for galaxy evolution and star formation. Optically-thin dense-gas tracers, such as isotopologues of HCN, HCO+, etc., are very helpful to diagnose excitation conditions of dense molecular gas. However, previous studies…

Astrophysics of Galaxies · Physics 2022-08-03 Fei Li , Zhi-Yu Zhang , Junzhi Wang , Feng Gao , Shanghuo Li , Jing Zhou , Yichen Sun , Ziyi Guo , Shu Liu

We use archival ALMA observations of the HCN and CO $J=1-0$ transitions, in addition to the radio continuum at 93 GHz, to assess the relationship between dense gas, star formation, and gas dynamics in ten, nearby (U)LIRGs and late-type…

Astrophysics of Galaxies · Physics 2023-03-15 Ashley R. Bemis , Christine D. Wilson

We present an analysis of gas densities in the central R=300 parsecs of the Milky Way, focusing on three clouds: GCM-0.02-0.07 (the 50 km/s cloud), GCM-0.13-0.08 (the 20 km/s cloud), and GCM0.25+0.01 (the "Brick"). Densities are determined…

Astrophysics of Galaxies · Physics 2018-11-28 E. A. C. Mills , A. Ginsburg , K. Immer , J. M Barnes , L. Wiesenfeld , A. Faure , M. R. Morris , M. A. Requena-Torres

We present an analysis of the excitation conditions of the molecular gas in the streamers and the outflow of M82 based on observations obtained at the IRAM 30m telescope. Our analysis of J=1-0 and J=2-1 transitions of CO and 13CO and the…

Astrophysics · Physics 2009-11-11 A. Weiss , F. Walter , N. Z. Scoville

We present the 3 mm wavelength spectra of 28 local galaxy merger remnants obtained with the Large Millimeter Telescope. Fifteen molecular lines from 13 different molecular species and isotopologues were identified, and 21 out of 28 sources…

(Abridged) Context. Massive star formation is associated with energetic processes, which result in significant gas cooling via far-infrared (IR) lines. Velocity-resolved observations can constrain the kinematics of the gas, allowing the…

Astrophysics of Galaxies · Physics 2023-11-29 Hoang Thanh Dat , Agata Karska , Min Young Lee , Friedrich Wyrowski , Le Ngoc Tram , Aiyuan Y. Yang , Karl M. Menten

Trends observed in galaxies, such as the Gao \& Solomon relation, suggest a linear relation between the star formation rate and the mass of dense gas available for star formation. Validation of such relations requires the establishment of…

Astrophysics of Galaxies · Physics 2017-09-20 Jens Kauffmann , Paul F. Goldsmith , Gary Melnick , Volker Tolls , Andres Guzman , Karl M. Menten

H$_{\rm I}$ 21-cm and $^{12}$CO 2.6-mm line emissions respectively trace the atomic and molecular gas phases, but they miss most of the opaque H$_{\rm I}$ and diffuse H$_2$ present in the Dark Neutral Medium (DNM) at the transition between…

High Energy Astrophysical Phenomena · Physics 2018-03-28 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

We study the molecular gas content of 24 star-forming galaxies at $z=3-4$, with a median stellar mass of $10^{9.1}$ M$_{\odot}$, from the MUSE Hubble Ultra Deep Field (HUDF) Survey. Selected by their Lyman-alpha-emission and H-band…

Motivated by recent observations with Herschel/PACS, and the availability of new rate coefficients for the collisional excitation of CO (Yang et al. 2010), the excitation of warm astrophysical CO is revisited with the use of numerical and…

Astrophysics of Galaxies · Physics 2015-06-04 David A. Neufeld

We characterize the column density probability distributions functions (PDFs) of the atomic hydrogen gas, HI, associated with seven Galactic molecular clouds (MCs). We use 21 cm observations from the Leiden/Argentine/Bonn Galactic HI Survey…

Astrophysics of Galaxies · Physics 2016-10-05 Nia Imara , Blakesley Burkhart

We have mapped over 50 massive, dense clumps with four dense gas tracers: HCN J=1-0 and 3-2; and CS J=2-1 and 7-6 transitions. Spectral lines of optically thin H^{13}CN 3-2 and C^{34}S 5-4 were also obtained towards the map centers. These…

Astrophysics of Galaxies · Physics 2015-05-18 Jingwen Wu , Neal Evans , Yancy Shirley , Claudia Knez