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Related papers: Relative velocities between $^{13}$CO structures w…

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We present large-field (4.25~$\times$~3.75 deg$^2$) mapping observations toward the Galactic region centered at $l = 150\arcdeg, b = 3.5\arcdeg$ in the $J = 1-0$ emission line of CO isotopologues ($^{12}$CO, $^{13}$CO, and C$^{18}$O), using…

Astrophysics of Galaxies · Physics 2017-03-27 Fang Xiong , Xuepeng Chen , Ji Yang , Min Fang , Shaobo Zhang , Miaomiao Zhang , Xinyu Du , Wenshan Long

We present the results of ALMA-ACA 7 m-array observations in $^{12}$CO($J=2-1$), $^{13}$CO($J=2-1$), and C$^{18}$O($J=2-1$) line emission toward the molecular-gas disk in the Local Group spiral galaxy M33 at an angular resolution of 7".31…

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…

Astrophysics of Galaxies · Physics 2015-05-27 N. Imara , L. Blitz

We study the properties of giant molecular clouds (GMCs) from a smoothed particle hydrodynamics simulation of a portion of a spiral galaxy, modelled at high resolution, with robust representations of the physics of the interstellar medium.…

Astrophysics of Galaxies · Physics 2016-03-31 A. Duarte-Cabral , C. L. Dobbs

We report the results of a 100 square degree survey of the Taurus Molecular Cloud region in the J = 1-0 transition of 12CO and 13CO. The image of the cloud in each velocity channel includes ~ 3 million Nyquist sampled pixels on a 20" grid.…

Astrophysics · Physics 2009-12-08 Paul F. Goldsmith , Mark Heyer , Gopal Narayanan , Ronald Snell , Di Li , Chris Brunt

We present an analysis of the internal velocity structures of the newly identified sub-0.1 pc coherent structures, droplets, in L1688 and B18. By fitting 2D linear velocity fields to the observed maps of velocity centroids, we determine the…

We use two existing molecular cloud catalogs derived from the same CO survey and two catalogs derived from local dust extinction surveys to investigate the nature of the GMC mass-size relation in the Galaxy. We find that the four surveys…

Astrophysics of Galaxies · Physics 2020-07-22 C. J. Lada , T. M. Dame

We present the statistical properties of molecular clumps in the Galactic center 50 km s$^{-1}$ molecular cloud (GCM-0.02-0.07) based on observations of the CS $J=1-0$ emission line with the Nobeyama Millimeter Array. In the cloud, 37…

Astrophysics of Galaxies · Physics 2015-06-04 Masato Tsuboi , Atsushi Miyazaki

We present an analysis of local molecular clouds (-6 <VLSR< 30 km/s, i.e., <1.5 kpc) in the first Galactic quadrant (25.8{\deg} <l<49.7{\deg} and |b|<5{\deg}), a pilot region of the Milky Way Imaging Scroll Painting (MWISP) CO survey. Using…

Astrophysics of Galaxies · Physics 2020-07-29 Qing-Zeng Yan , Ji Yang , Yang Su , Yan Sun , Chen Wang

Using the PMO-13.7 m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of $^{12}$CO, $^{13}$CO, and C$^{18}$O $J=1-0$ emission toward the sky region centered at $l$=$209.7^\circ$,…

Astrophysics of Galaxies · Physics 2020-09-15 Chong Li , Hongchi Wang , Miaomiao Zhang , Yuehui Ma , Lianghao Lin

We have obtained 12CO and 13CO J=1-0 observations of the nearby spiral galaxy M33 to try to resolve the long-standing discrepancy between 12CO/13CO line ratios measured in Galactic giant molecular clouds and external galaxies.…

Astrophysics · Physics 2009-10-22 C. D. Wilson , C. E. Walker

We have analysed the chemical and kinematic properties of the 20 and 50 km s$^{-1}$ molecular clouds in the Central Molecular Zone of the Milky Way Galaxy, as well as those of the molecular ridge bridging these two clouds. Our work has…

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…

The physical properties of molecular clouds are often measured using spectral-line observations, which provide the only probes of the clouds' velocity structure. It is hard, though, to assess whether and to what extent intensity features in…

Astrophysics of Galaxies · Physics 2015-06-17 Christopher N. Beaumont , Stella S. R. Offner , Rahul Shetty , Simon C. O. Glover , Alyssa A. Goodman

Molecular cloud collisions are a prominent theory for the formation of stars. Observational studies into cloud collisions identify the collision via a bridging feature: a continuous strip of line emission that connects two intensity peaks…

Astrophysics of Galaxies · Physics 2024-10-25 Rees A. Barnes , Felix D. Priestley

We present a new large-scale survey of J=3-2 12CO emission covering 4.8 square degrees around the Rosette Nebula. Approximately 2000 compact clumps are identified, with a spatially-invariant power law mass distribution index of -1.8. Most…

In this work we use models of molecular clouds (MC), and non-LTE radiative transfer calculations, to obtain a theoretical calibration of the relation between LTE 13CO column density and true column density in MCs. The cloud models consist…

Astrophysics · Physics 2008-02-03 Paolo Padoan , Mika Juvela , John Bally , AAke Nordlund

Molecular clouds are regions of dense gas and dust in space where new stars and planets are born. There is a strong correlation between the distribution of dust and molecular gas in molecular clouds. The present work focuses on the…

Astrophysics of Galaxies · Physics 2024-10-28 Rui-Zhi Li , Bing-Qiu Chen , Guang-Xing Li , Bo-Ting Wang , Hao-Ming Ren , Qi-Ning Guo

The Halo Assembly in Lambda-CDM: Observations in 7 Dimensions (HALO7D) dataset consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope-measured proper motions of Milky Way halo main sequence turnoff stars in the CANDELS fields.…

Studying the atomic-to-molecular transition is essential for understanding the evolution of interstellar medium. The linear edge of Taurus molecular cloud, clearly identified in the $^{13}$CO(1-0) intensity map, serves as an ideal site for…

Astrophysics of Galaxies · Physics 2025-04-03 Ningyu Tang , Feihang Miao , Gan Luo , Di Li , Junzhi Wang , Fujun Du , Donghong Wu , Shu Liu