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We investigate the presence of COMs in strongly UV-irradiated interstellar molecular gas. We have carried out a complete millimetre line survey using the IRAM30m telescope towards the edge of the Orion Bar photodissociation region (PDR),…

Astrophysics of Galaxies · Physics 2017-07-26 S. Cuadrado , J. R. Goicoechea , J. Cernicharo , A. Fuente , J. Pety , B. Tercero

Dusty star-forming galaxies (DSFGs) at redshift z$\geq$1 are among the most vigorously star-forming galaxies in the Universe. However, their dense ($\geq$10$^5$ cm$^{-3}$ ) gas phase - typically traced by HCN(1-0) - remains almost entirely…

Astrophysics of Galaxies · Physics 2022-11-09 M. Rybak , J. A. Hodge , T. R. Greve , D. Riechers , I. Lamperti , J. van Marrewijk , F. Walter , J. Wagg , P. P. van der Werf

Observations of various molecular lines toward a disk region of a nearby galaxy are now feasible, and they are being employed as diagnostic tools to study star-formation activities there. However, the spatial resolution attainable for a…

Astrophysics of Galaxies · Physics 2019-07-17 Yuri Nishimura , Yoshimasa Watanabe , Nanase Harada , Kotaro Kohno , Satoshi Yamamoto

Aims: Our aim is to identify the dominant molecular cooling lines and characteristic emission features in the 1.3 mm window of distinct regions in the northern part of the Orion A molecular cloud. By defining and analysing template regions,…

Astrophysics of Galaxies · Physics 2020-04-15 N. Brinkmann , F. Wyrowski , J. Kauffmann , D. Colombo , K. M. Menten , X. D. Tang , R. Güsten

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

Solar and Stellar Astrophysics · Physics 2014-09-05 Zhiyuan Ren , Yuefang Wu , Tie Liu , Lixin Li , Di Li , Binggang Ju

\abridged The nuclei of active galaxies harbor massive young stars, an accreting central black hole, or both. In order to determine the physical conditions that pertain to molecular gas close to the sources of radiation, numerical models…

Astrophysics · Physics 2009-11-11 R. Meijerink , M. Spaans , F. P. Israel

While the best tracer of the molecular component and its dynamics in galaxies is the CO molecule, which excitation is revealed by its isotopic and (2-1)/(1-0) ratios, the denser gas is revealed by molecules such as HCN, HNC, HCO+ or CN,…

Astrophysics · Physics 2007-09-25 F. Combes

In recent decades, significant attention has been dedicated to analytical and observational studies of the atomic hydrogen (HI) to molecular hydrogen (H2) transition in the interstellar medium. We focussed on the Draco diffuse cloud to gain…

We present the detection of multiple CO line transitions with ALMA in a few tens of infrared-selected galaxies on and above the main sequence at z=1.1-1.7. We reliably detected the emission of CO(5-4), CO(2-1), and CO(7-6)+[CI](2-1) in 50,…

We present $^{12}$CO(J=1--0) line observations of 22 low-luminosity spiral galaxies in the Virgo cluster. These data, together with 244 others available in the literature, allow us to build a large sample that we use to study the molecular…

Astrophysics · Physics 2009-08-21 A. Boselli , J. Lequeux , G. Gavazzi

The carbon monoxide (CO) rotational transition lines are the most common tracers of molecular gas within giant molecular clouds (MCs). We study the ratio ($R_{2-1/1-0}$) between CO's first two emission lines and examine what information it…

Astrophysics of Galaxies · Physics 2016-12-21 Camilo H. Peñaloza , Paul C. Clark , Simon C. O. Glover , Rahul Shetty , Ralf S. Klessen

This paper presents a large spectral line and continuum survey of 8 deeply embedded, low-mass protostellar cores using the Submillimeter Array. Each source was observed in high excitation lines of some of the most common molecular species,…

We perform a complete census of molecular ions with an abundance larger than 1e-10 in the protostellar shock L1157-B1 by means of an unbiased high-sensitivity survey obtained with the IRAM-30m and Herschel/HIFI. By means of an LVG radiative…

Astrophysics of Galaxies · Physics 2015-06-18 L. Podio , B. Lefloch , C. Ceccarelli , C. Codella , R. Bachiller

We investigate the physical properties of gas structures under feedback in the G333 complex using data of the 13CO (3-2) line in the LAsMA observation. We used the Dendrogram algorithm to identify molecular gas structures based on the…

Astrophysics of Galaxies · Physics 2024-02-14 J. W. Zhou , F. Wyrowski , S. Neupane , I. Barlach Christensen , K. M. Menten , S. H. Li , T. Liu

Our understanding of how molecular clouds form in the interstellar medium (ISM) would be greatly helped if we had a reliable observational tracer of the gas flows responsible for forming the clouds. Fine structure emission from singly…

Astrophysics of Galaxies · Physics 2019-05-14 Paul C. Clark , Simon C. O. Glover , Sarah E. Ragan , Ana Duarte-Cabral

We present a study of molecular outflows using six molecular lines (including 12CO/13CO/C18O/HCO+(J = 1-0) and SiO/CS(J = 2-1)) toward nine nearby high-mass star-forming regions with accurate known distances. This work is based on the…

Astrophysics of Galaxies · Physics 2021-03-10 De-Jian Liu , Ye Xu , Ying-Jie Li , Sheng Zheng , Deng-Rong Lu , Chao-Jie Hao , Ze-Hao Lin , Shuai-Bo Bian , Li-Ming Liu

Estimating molecular abundances ratios from the direct measurement of the emission of the molecules towards a variety of interstellar environments is indeed very useful to advance in our understanding of the chemical evolution of the…

Astrophysics of Galaxies · Physics 2018-09-12 S. Paron , M. B. Areal , M. E. Ortega

Using arguments parallel to those used in support of using H2CO as a sensitive probe of temperature and density in molecular clouds, we measured the J=7-6 and J=10-9 transitions of thioformaldehyde (H2CS) in several hot core sources. The…

Astrophysics of Galaxies · Physics 2009-07-24 Alwyn Wootten , Jeffrey G. Mangum

We present the results from a survey for 12CO emission in 40 luminous sub-millimetre galaxies (SMGs), with 850um fluxes of S850 = 4 - 20 mJy, conducted with the Plateau de Bure Interferometer. We detect 12CO emission in 32 SMGs at z~1.2 -…

Star formation at earlier cosmological times takes place in an interstellar medium with low metallicity. The Large Magellanic Cloud (LMC) is ideally suited to study star formation in such an environment. The physical and chemical state of…