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We attempt to visually classify the morphologies of 18190 molecular clouds, which are identified in the $^{12}$CO(1-0) spectral line data over $\sim$ 450 deg$^{2}$ of the second Galactic quadrant from the Milky Way Imaging Scroll Painting…

Astrophysics of Galaxies · Physics 2021-12-08 Lixia Yuan , Ji Yang , Fujun Du , Xunchuan Liu , Shaobo Zhang , Zehao Lin , Jingfei Sun , Qing-Zeng Yan , Yuehui Ma , Yang Su , Yan Sun , Xin Zhou

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Astrophysics · Physics 2009-11-13 M. Dessauges-Zavadsky , F. Combes , D. Pfenniger

We recently reported a population of protostellar candidates in the 20 km s$^{-1}$ cloud in the Central Molecular Zone of the Milky Way, traced by H$_2$O masers in gravitationally bound dense cores. In this paper, we report…

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

We present an analysis of 55 central galaxies in clusters and groups with molecular gas masses and star formation rates lying between $10^{8}-10^{11}\ M_{\odot}$ and $0.5-270$ $M_{\odot}\ yr^{-1}$, respectively. We have used Chandra…

Astrophysics of Galaxies · Physics 2018-02-21 F. A. Pulido , B. R. McNamara , A. C. Edge , M. T. Hogan , A. N. Vantyghem , H. R. Russell , P. E. J. Nulsen , I. Babyk , P. Salomé

We present results of a wide-field (approximately 60 x 90 pc) ALMA mosaic of CO(2-1) and $^{13}$CO(2-1) emission from the molecular cloud associated with the 30 Doradus star-forming region. Three main emission complexes, including two…

Using the IRAM 30m telescope two molecular structures have been detected which cover very small areas, FWHM<1'. The clouds have velocities of v_lsr~5kms and linewidth of dv~0.8km/s; thus they belong most likely to the Milky Way. Applying…

Astrophysics · Physics 2009-11-07 Andreas Heithausen

We present observations of 4.25 square degree area toward the North American and Pelican Nebulae in the $J = 1-0$ transitions of $^{12}$CO, $^{13}$CO, and C$^{18}$O. Three molecules show different emission area with their own distinct…

Solar and Stellar Astrophysics · Physics 2015-06-18 Shaobo Zhang , Ye Xu , Ji Yang

We present the first numerical simulations that self-consistently follow the formation of dense molecular clouds in colliding flows. Our calculations include a time-dependent model for the H2 and CO chemistry that runs alongside a detailed…

Astrophysics of Galaxies · Physics 2015-06-04 Paul C. Clark , Simon C. O. Glover , Ralf S. Klessen , Ian A. Bonnell

We discuss the fragmentation of a filamentary cloud on the basis of a 1-dimensional hydrodynamical simulation of a self-gravitating gas cloud. The simulation shows that dense cores are produced with a semi-regular interval in space and time…

Astrophysics · Physics 2009-10-22 Tomoyuki Hanawa , Satoshi Yamamoto , Yasuhiro Hirahara

We present Nobeyama 45m telescope C18O, 13CO, and 12CO(1-0) mapping observations towards an interstellar filament in the Taurus molecular cloud. We investigate the gas velocity structure along the filament and in its surrounding parent…

Astrophysics of Galaxies · Physics 2018-09-26 Doris Arzoumanian , Yoshito Shimajiri , Shu-ichiro Inutsuka , Tsuyoshi Inoue , Kengo Tachihara

We report the discovery of a dense molecular ring-like structure in a dense (10$^5$ cm$^{-3}$), cold (pc-scale CO depletion at a factor of 5), and young (10$^4$ year) star-forming region G34.74-0.12, revealed by C$^{18}$O (2-1), HNC (1-0),…

Filamentary molecular clouds are an essential intermediate stage in the star formation process. To test whether these structures are universal throughout cosmic star formation history, it is crucial to study low-metallicity environments…

We use sub-arcsecond resolution ($\sim$0.4$''$) observations with NOEMA at 1.37 mm to study the dust emission and molecular gas of 18 high-mass star-forming regions. We combine the derived physical and chemical properties of individual…

We review recent advances in the analytical and numerical modeling of the star formation rate in molecular clouds and discuss the available observational constraints. We focus on molecular clouds as the fundamental star formation sites,…

Star formation activity in molecular clouds is often found to be correlated with the amount of material above a column density threshold of $\sim 10^{22} \, {\rm cm^{-2}}$. Attempts to connect this column density threshold to a ${\it…

Astrophysics of Galaxies · Physics 2023-10-11 F. D. Priestley , P. C. Clark , S. C. O. Glover , S. E. Ragan , O. Fehér , L. R. Prole , R. S. Klessen

Filamentary structures are ubiquitous in high-mass star-forming molecular clouds. Their relation with high-mass star formation is still to be understood. Here we report interferometric observations toward 8 filamentary high-mass…

The Galactic HII region G353.2+0.9 is excited by the massive open cluster Pismis-24. By analyzing (sub-)mm molecular-line and -continuum we study the detailed morphology of the gas and dust, as well as their physical parameters and their…

Astrophysics of Galaxies · Physics 2015-06-03 A. Giannetti , J. Brand , F. Massi , A. Tieftrunk , M. T. Beltran

We have studied the filaments extracted from the column density maps of the nearby Lupus 1, 3, and 4 molecular clouds, derived from photometric maps observed with the Herschel satellite. Filaments in the Lupus clouds have quite low column…