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相关论文: Rethinking a Mysterious Molecular Cloud

200 篇论文

We present 45"-47" angular resolution maps at 50" sampling of the 12CO and 13CO J=1-0 emission toward a 1.39 deg x 1.33 deg region in the W51 HII region complex. These data permit the spatial and kinematic separation of several spectral…

天体物理学 · 物理学 2009-10-30 John M. Carpenter , D. B. Sanders

We report the detection of a peculiar molecular cloud, CO 0.02-0.02, lying about 5' Galactic-east from the center of the Galaxy. (12)CO images taken with NRO 45 m telescope showed that it is relatively compact (about 3x4 pc^2) as well as…

天体物理学 · 物理学 2009-10-31 T. Oka , G. J. White , T. Hasegawa , F. Sato , M. Tsuboi , A. Miyazaki

The rate of star formation both in the Galaxy and in external galaxies should be related to the physical properties of the molecular clouds from which stars form. This is expected for the starbursts found both in irregular galaxies and in…

星系天体物理 · 物理学 2015-05-13 G. Santangelo , L. Testi , L. Gregorini , S. Leurini , L. Vanzi , C. M. Walmsley , D. J. Wilner

We present a detailed analysis comparing the velocity fields in molecular clouds and the atomic gas that surrounds them in order to address the origin of the gradients. To that end, we present first-moment intensity-weighted velocity maps…

星系天体物理 · 物理学 2015-05-27 N. Imara , L. Blitz

Spatial association of clumps from different tracers turns out to be a valuable tool to determine the physical properties of molecular clouds. It provides a reliable estimate for the $X$-factors, serves to trace the density of clumps seen…

We report the spatial distribution and physical characteristics of molecular clouds in the G24 region, which is located near the intersection of the Milky Way's Galactic bar with the Norma arm and the 3 kpc arm. Utilizing molecular line…

星系天体物理 · 物理学 2025-03-21 Tian Yang , Xi Chen , Xiao-Yun Xu , Yang Yang , En Chen , Jun Li , Bing-Gang Ju , Deng-Rong Lu

There is a robust polyatomic chemistry in diffuse, partially-molecular interstellar gas that is readily accessible in absorption at radio/mm/sub-mm wavelengths. Accurate column densities are derived owing to the weak internal excitation, so…

星系天体物理 · 物理学 2023-02-15 Harvey Liszt , Maryvonne Gerin

For many years feedback processes generated by OB-stars in molecular clouds, including expanding ionization fronts, stellar winds, or UV-radiation, have been proposed to trigger subsequent star formation. However, hydrodynamic models…

The rotational transitions of carbon monoxide (CO) are the primary means of investigating the density and velocity structure of the molecular interstellar medium. Here we study the lowest four rotational transitions of CO towards…

天体物理学 · 物理学 2009-10-31 James G. Ingalls , T. M. Bania , Adair P. Lane , Matthias Rumitz , Antony A. Stark

The sample of 566 molecular clouds identified in the CO(2--1) IRAM survey covering the disk of M~33 is explored in detail.The clouds were found using CPROPS and were subsequently catalogued in terms of their star-forming properties as…

星系天体物理 · 物理学 2018-05-02 Jonathan Braine , Erik Rosolowsky , Pierre Gratier , Edvige Corbelli , Karl Schuster

Two selected regions in the molecular gas spiral arms in M51 were mapped with the Owens Valley Radio Observatory (OVRO) mm-interferometer in the 12CO(2-1), 13CO(1-0), C18O(1-0), HCN(1-0) and HCO+(1-0) emission lines. The CO data have been…

宇宙学与河外天体物理 · 物理学 2015-05-19 E. Schinnerer , A. Weiss , S. Aalto , N. Z. Scoville

We present the highest resolution (1") $^{12}$CO(1-0) observations of molecular gas in the dwarf starburst galaxy NGC 625, to date, obtained with ALMA. Molecular gas is distributed in discrete clouds within an area of $0.4$ kpc$^2$ and does…

星系天体物理 · 物理学 2020-05-27 Nia Imara , Ilse De Looze , Christopher M. Faesi , Diane Cormier

We observed a 10x20 pc region of the molecular cloud M17 in the 12CO and 13CO J=3-2 and J=2-1 transitions to determine their global behavior and to assess the reliability of using ratios of CO line intensities integrated over an entire…

天体物理学 · 物理学 2009-10-31 C. D. Wilson , J. E. Howe , M. L. Balogh

The Rosette molecular cloud is promoted as the archetype of a triggered star-formation site. This is mainly due to its morphology, because the central OB cluster NGC 2244 has blown a circular-shaped cavity into the cloud and the expanding…

Does star formation proceed in the same way in large spirals such as the Milky Way and in smaller chemically younger galaxies? Earlier work suggests a more rapid transformation of H$_2$ into stars in these objects but (1) a doubt remains…

星系天体物理 · 物理学 2016-04-20 Jonathan Braine , Pierre Gratier , Carsten Kramer , Karl F. Schuster , Fatemeh Tabatabaei , Erwan Gardan

The amount of H$_2$ present in spiral galaxies remains uncertain, particularly in the dim outer regions and in low-metallicity environments. We present high-resolution CO(1--0) observations with the Plateau de Bure interferometer of the…

星系天体物理 · 物理学 2016-04-20 J. Braine , P. Gratier , Y. Contreras , K. F. Schuster , N. Brouillet

We present an analysis of Giant Molecular Clouds (GMCs) within hydrodynamic simulations of isolated, low-mass (M* ~ 10^9 M_sol) disc galaxies. We study the evolution of molecular abundances and the implications for CO emission and the X_CO…

星系天体物理 · 物理学 2016-07-27 Alexander J. Richings , Joop Schaye

We present the results of a study of simulated Giant Molecular Clouds (GMCs) formed in a Milky Way-type galactic disk with a flat rotation curve. This simulation, which does not include star formation or feedback, produces clouds with…

星系天体物理 · 物理学 2015-06-16 Samantha M. Benincasa , Elizabeth J. Tasker , Ralph E. Pudritz , James Wadsley

We present 3D "zoom-in" simulations of the formation of two molecular clouds out of the galactic interstellar medium. We model the clouds - identified from the SILCC simulations - with a resolution of up to 0.06 pc using adaptive mesh…

星系天体物理 · 物理学 2017-10-18 D. Seifried , S. Walch , P. Girichidis , T. Naab , R. Wünsch , R. S. Klessen , S. C. O. Glover , T. Peters , P. Clark

We studied the H$_2$ column density probability distribution function (N-PDF) based on molecular emission lines using the Nobeyama 45-m Cygnus X CO survey data. Using the DENDROGRAM and SCIMES algorithms, we identified 124 molecular clouds…