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Related papers: Observations of chemical differentiation in clumpy…

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Molecular clouds (MC) are structures of dense gas in the interstellar medium (ISM), that extend from ten to a few hundred parsecs and form the main gas reservoir available for star formation. Hydrodynamical simulations of varying complexity…

The growing range of automated algorithms for the identification of molecular clouds and clumps in large observational datasets has prompted the need for the direct comparison of these procedures. However, these methods are complex and…

Astrophysics of Galaxies · Physics 2023-05-31 Raffaele Rani , Toby J. T. Moore , David J. Eden , Andrew J. Rigby , Ana Duarte-Cabral , Yueh-Ning Lee

The past decade has led to significant improvements in our understanding of the physical structure of the molecular cores of cold dark clouds. Observational efforts, in combination with improved knowledge of cloud structure, now provide…

Astrophysics · Physics 2007-05-23 Edwin A. Bergin

Describing how the properties of the interstellar medium combine across size-scales is crucial for understanding star formation scaling laws and connecting Galactic and extragalactic data of molecular clouds. We describe how the statistical…

Astrophysics of Galaxies · Physics 2021-09-15 Andri Spilker , Jouni Kainulainen , Jan Orkisz

Complex organic molecules (COMs) are widely detected in protostellar and protoplanetary systems, where they are thought to have been inherited in large part from earlier evolutionary phases. The chemistry of COMs in these earlier phases,…

Astrophysics of Galaxies · Physics 2025-01-31 F. D. Priestley , P. C. Clark , S. E. Ragan , S. Scibelli , M. T. Cusack , S. C. O. Glover , O. Fehér , L. R. Prole , R. S. Klessen

Aims. Our goals are to compare the CS, N2H+ and dust distributions in a representative sample of high-mass star forming dense cores and to determine the physical and chemical properties of these cores. Methods. We compare the results of…

Astrophysics · Physics 2009-11-11 L. Pirogov , I. Zinchenko , P. Caselli , L. E. B. Johansson

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

The dense cloud associated with W40, one of the nearby H II regions, has been studied in millimeter-wave molecular lines and in 1.2 mm continuum. Besides, 1280 MHz and 610 MHz interferometric observations have been done. The cloud has…

Astrophysics of Galaxies · Physics 2015-06-17 L. Pirogov , D. K. Ojha , M. Thomasson , Y. -F. Wu , I. Zinchenko

The structure of molecular clouds can be characterized with the probability distribution function (PDF) of the mass surface density. In particular, the properties of the distribution can reveal the nature of the turbulence and star…

Astrophysics of Galaxies · Physics 2015-06-22 Rachel L. Ward , James Wadsley , Alison Sills

The 1-50 GHz GBT PRIMOS data contains ~50 molecular absorption lines observed in diffuse and translucent clouds located in the Galactic Center, Bar, and spiral arms in the line-of-sight to Sgr B2(N). We measure the column densities and…

Astrophysics of Galaxies · Physics 2018-02-14 Joanna Corby , Brett McGuire , Eric Herbst , Anthony Remijan

We present Jansky Very Large Array observations of 20 - 37 GHz absorption lines from nearby Galactic diffuse molecular gas seen against four cosmologically-distant compact radio continuum sources. The main new observational results are that…

Astrophysics of Galaxies · Physics 2018-04-18 Harvey Liszt , Maryvonne Gerin , Anthony Beasley , Jerome Pety

(Abridged) We present evidence that low-mass starless cores, the simplest units of star formation, are systematically differentiated in their chemical composition. Molecules including CO and CS almost vanish near the core centers, where the…

Astrophysics · Physics 2008-11-26 M. Tafalla , P. C. Myers , P. Caselli , C. M. Walmsley , C. Comito

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

In recent years, there were studies on the omnipresence and structures of filaments in star-forming regions, and the role of their fragmentation in the process of star formation. However, only a few studies analysed the evolution of…

Astrophysics of Galaxies · Physics 2018-06-07 Roxana-Adela Chira

The existence of high galactic latitude molecular clouds has been known for several decades, and studies of their dust and gas distributions reveal complicated morphological structures. Their dynamics involve turbulence even in the absence…

Astrophysics of Galaxies · Physics 2025-08-20 Marco Monaci , Loris Magnani , Steven N. Shore

We employ the Delta-variance analysis and study the turbulent gas dynamics of simulated molecular clouds (MCs). Our models account for a simplified treatment of time-dependent chemistry and the non-isothermal nature of the gas. We…

Solar and Stellar Astrophysics · Physics 2015-08-06 Erik Bertram , Ralf S. Klessen , Simon C. O. Glover

We used CO (2-1) and CO (1-0) data cubes to identify molecular clouds and study their kinematics and dynamics in three nearby galaxies and the inner Milky Way. When observed at similar spatial and velocity resolutions, molecular clouds in…

Astrophysics of Galaxies · Physics 2025-11-03 J. W. Zhou , Sami Dib

The evolution of molecular clouds in galactic centres is thought to differ from that in galactic discs due to a significant influence of the external gravitational potential. We present a set of numerical simulations of molecular clouds…

We present a CSO and BIMA molecular line survey of the dense, quiescent molecular environment ahead of HH2. The molecular gas is cold, 13 K, and moderately dense, 3x10^5 cm^-3. A total of 14 species has been detected (including different…

Astrophysics · Physics 2009-11-07 J. M. Girart , S. Viti , D. A. Williams , R. Estalella , P. T. P Ho

We present a large catalogue of molecular clouds with accurate distance estimates in the southern sky. Based on the three-dimensional (3D) dust extinction map and the best-fit extinction and distance information of over 17 million stars…

Astrophysics of Galaxies · Physics 2022-02-23 Helong Guo , Bingqiu Chen , Xiaowei Liu