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The 23 GHz emission lines from the NH3 rotation inversion transitions are widely used to investigate the kinematics and physical conditions in dense molecular clouds. The line profile is composed of hyperfine components which can be used to…

Astrophysics · Physics 2009-11-07 Robeson S. McGary , Paul T. P. Ho

Multiple molecular lines with radiative transfer modelling are a powerful tool to probe the physics of star-forming gas in galaxies. We investigate the gas properties in the centre of the spiral galaxy NGC 2903 using low-J CO lines, i.e.…

Astrophysics of Galaxies · Physics 2020-05-14 Selçuk Topal

With a goal toward deriving the physical conditions in external galaxies, we present a survey of the formaldehyde emission in a sample of starburst systems. By extending a technique used to derive the spatial density in star formation…

Astrophysics · Physics 2009-11-13 Jeffrey G. Mangum , Jeremy Darling , Karl M. Menten , Christian Henkel

We present 3 mm observations obtained with the IRAM 30-m telescope for ten nearby gas-rich active galaxies spanning three orders of magnitude in infrared luminosity. Emission lines of HCO+(1-0), HCN(1-0), and C2H(1-0) were simultaneously…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Xuejian Jiang , Junzhi Wang , Qiusheng Gu

Column-density maps of molecular clouds are one of the most important observables in the context of molecular cloud- and star-formation (SF) studies. With the Herschel satellite it is now possible to determine the column density from dust…

Astrophysics of Galaxies · Physics 2015-03-04 N. Schneider , V. Ossenkopf , T. Csengeri , R. Klessen , C. Federrath , P. Tremblin , P. Girichidis , S. Bontemps , Ph. Andre

We present spectra of the extended 12CO and 13CO J=1-0 emission along the major axes of 17 nearby galaxies. Spatial variations in the ratio of CO and 13CO integrated intensities, R, are found in nearly every galaxy observed. There is an…

High-redshift dusty star-forming galaxies with very high star formation rates (500 -- 3000 M$_{\odot}$ yr$^{-1}$) are key to understanding the formation of the most extreme galaxies in the early Universe. Characterising the gas reservoir of…

It is important to understand the origin of molecular line intensities and chemical composition in the molecular-cloud scale in the Galactic sources because it serves as a benchmark to compare with the chemical compositions of extragalactic…

Astrophysics of Galaxies · Physics 2019-02-13 Nanase Harada , Yuri Nishimura , Yoshimasa Watanabe , Satoshi Yamamoto , Yuri Aikawa , Nami Sakai , Takashi Shimonishi

The relationship between the star formation rate surface density and the molecular gas surface density in galaxies is key to understanding galaxy evolution. To investigate the molecular Kennicutt-Schmidt (K-S) relation and its dependence on…

Astrophysics of Galaxies · Physics 2026-04-13 Victoria G. G. Samboco , Ryan P. Keenan

We report on detections of the high-excitation CO J=6-5, J=4-3 lines in Mrk231, a prototypical Ultra Luminous Infrared Galaxy (ULIRG) and Seyfert 1 QSO. These observations are combined with CO J=3-2, HCN J=4-3 (this work), and CO J=2-1,…

Astrophysics · Physics 2019-08-19 Padeli P. Papadopoulos , Kate G. Isaak , Paul P. van der Werf

Most studies of high-mass star formation focus on massive luminous clumps, but the physical properties of their larger scale environment are poorly known. In this work, we aim at characterising the effects of clustered star formation and…

Astrophysics of Galaxies · Physics 2015-06-12 S. Leurini , F. Wyrowski , F. Herpin , F. van der Tak , R. Guesten , E. F. van Dishoeck

We present the results of a survey of CO(1-0) emission in 14 infrared luminous dusty star forming galaxies (DSFGs) at 2 < z < 4 with the NSF's Karl G. Jansky Very Large Array. All sources are detected in CO(1-0), with an ~1arcsec angular…

Massive, intensely star-forming galaxies at high redshift require a supply of molecular gas from their gas reservoirs, replenished by infall from the surrounding circumgalactic medium, to sustain their immense star-formation rates. However,…

We report the first uniform and systematic study of dust and molecular gas in nearby molecular clouds. We use surveys of dust extinction and emission to determine the opacity and map the distribution of the dust within a dozen local clouds…

Astrophysics of Galaxies · Physics 2022-05-25 John Arban Lewis , Charles J. Lada , Thomas Dame

We present new observations of HCN and HCO+in the circumnuclear disk (CND) of the Galaxy, obtained with the APEX telescope. We have mapped emission in rotational lines of HCN J = 3-2, 4-3, and 8-7, as well as HCO+ J = 3-2, 4-3, and 9-8. We…

Astrophysics of Galaxies · Physics 2015-06-17 Elisabeth A. C. Mills , Rolf Güsten , Miguel A. Requena Torres , Mark R. Morris

Low mass star-forming regions are more complex than the simple spherically symmetric approximation that is often assumed. We apply a more realistic infall/outflow physical model to molecular/continuum observations of three late Class 0…

Astrophysics of Galaxies · Physics 2013-08-26 J. M. C. Rawlings , M. P. Redman , P. B. Carolan

We report the results of our observations of the 12CO (J=1-0) and 12CO (J=3-2) line emission of 74 major giant molecular clouds (GMCs) within the galactocentric distance of 5.1 kpc in the Local Group galaxy M33. The observations have been…

We present Herschel SPIRE Fourier Transform Spectrometer (FTS) observations of N159W, an active star-forming region in the Large Magellanic Cloud (LMC). In our observations, a number of far-infrared cooling lines including CO(4-3) to…

We used the KOSMA 3m telescope to map the core 7'x5' of the Galactic massive star forming region W3Main in the two fine structure lines of atomic carbon and four mid-J transitions of CO and 13CO. The maps are centered on the luminous…

Astrophysics · Physics 2009-11-10 C. Kramer , H. Jakob , B. Mookerjea , N. Schneider , M. Bruell , J. Stutzki