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Related papers: Which Molecular Cloud Structures Are Bound?

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Emission from carbon monoxide (CO) is ubiquitously used as a tracer of dense star forming molecular clouds. There is, however, growing evidence that a significant fraction of CO emission originates from diffuse molecular gas. Quantifying…

Astrophysics of Galaxies · Physics 2016-03-09 Julia Roman-Duval , Mark Heyer , Christopher Brunt , Paul Clark , Ralf Klessen , Rahul Shetty

Low-mass stars are generally understood to form by the gravitational collapse of the dense molecular clouds known as starless cores. Continuum observations have not been able to distinguish among the several different hypotheses that…

Solar and Stellar Astrophysics · Physics 2015-06-23 Eric Keto , Paola Caselli , Jonathan Rawlings

Observational and theoretical evidence suggests that a substantial population of molecular clouds (MCs) appear to be unbound, dominated by turbulent motions. However, these estimations are made typically via the so-called viral parameter…

Clouds containing molecular dark matter in quantities relevant for star formation may exist in minihaloes of the type of cold dark matter included in many cosmological simulations or in the regions of some galaxies extending far beyond…

Astrophysics · Physics 2008-11-26 T. A. Bell , T. W. Hartquist , S. Viti , D. A. Williams

We present the first results from a new carbon monoxide (CO) survey of the southern Galactic plane being conducted with the Mopra radio telescope in Australia. The 12CO, 13CO and C18O J=1-0 lines are being mapped over the l = 305-345 deg, b…

The molecular gas content of local early-type galaxies is constrained and discussed in relation to their evolution. First, as part of the Atlas3D survey, we present the first complete, large (260 objects), volume-limited single-dish survey…

We present new mm interferometric and optical integral-field unit (IFU) observations and construct a sample of 12 E and S0 galaxies with molecular gas which have both CO and optical maps. The galaxies contain 2 x 10^7 to 5 x 10^9 M\odot of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Alison F. Crocker , Martin Bureau , Lisa M. Young , Francoise Combes

Molecular clouds are supported by turbulence and magnetic fields, but quantifying their influence on cloud lifecycle and star formation efficiency (SFE) remains an open question. We perform radiation MHD simulations of star-forming giant…

Astrophysics of Galaxies · Physics 2021-05-05 Jeong-Gyu Kim , Eve C. Ostriker , Nina Filippova

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…

Astrophysics · Physics 2009-10-31 C. D. Wilson , J. E. Howe , M. L. Balogh

The cloud-scale density, velocity dispersion, and gravitational boundedness of the interstellar medium (ISM) vary within and among galaxies. In turbulent models, these properties play key roles in the ability of gas to form stars. New high…

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 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 present a systematic analysis of the velocity structure functions (VSFs) of 167 molecular clouds with angular sizes greater than $\sim$176 arcmin$^2$ in three sectors of the Galactic mid-plane. We calculated the 1st- to 3rd-order VSFs…

CO observations have been so far the best way to trace molecular gas in external galaxies, but at low metallicity the gas mass deduced could be largely underestimated. At present, the kinematic information of CO data cubes are used to…

Astrophysics · Physics 2019-08-19 C. Bot , F. Boulanger , M. Rubio , F. Rantakyro

We present high resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M82. Six 12CO lines, 2 13CO lines and 4 fine-structure lines are detected. Besides showing the effects of the overall velocity structure of the…

The complexity of physico-chemical models of star formation is increasing, with models that take into account new processes and more realistic setups. These models allow astrochemists to compute the evolution of chemical species throughout…

Astrophysics of Galaxies · Physics 2019-07-17 Thomas H. G. Vidal , Pierre Gratier , Neil Vaytet , Audrey Coutens , Valentine Wakelam

The physical conditions of the Galactic center (GC) clouds moving with non-circular velocities are not well-known. We have studied the physical conditions of these clouds with the aim of better understanding the origin of the outstanding…

The observed star formation rate of the Milky Way can be explained by applying a metallicity-dependent factor to convert CO luminosity to molecular gas mass and a star formation efficiency per free-fall time that depends on the virial…

Astrophysics of Galaxies · Physics 2022-04-27 Neal J. Evans , Jeong-Gyu Kim , Eve C. Ostriker

The C$_2$H $N=1-0$ transition was used to investigate the possible line of sight sub-structures from the dense and optically thick in $^{13}$CO $J=1-0$ regions in the Ophiuchus star forming molecular cloud. With a 0.2 K or lower noise,…

Astrophysics of Galaxies · Physics 2025-03-13 Lei qian , Zhichen Pan , Dongyue Jiang , Zichen Huang

The most extensive survey of carbon monoxide (CO) gas in the Taurus molecular cloud relied on $^{12}$CO and $^{13}$CO $J=1 \rightarrow 0$ emission only, distinguishing the region where $^{12}$CO is detected without $^{13}$CO (named mask 1…

Astrophysics of Galaxies · Physics 2023-08-02 Yan Duan , Di Li , Laurent Pagani , Paul F. Goldsmith , Tao-Chung Ching , Chen Wang , Jinjin Xie