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Related papers: A High-Resolution Study of the CO-H2 Conversion Fa…

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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 present and analyze deep Herschel/HIFI observations of the [CII] 158um, [CI] 609um, and [CI] 370um lines towards 54 lines-of-sight (LOS) in the Large and Small Magellanic clouds. These observations are used to determine the physical…

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…

Astrophysics of Galaxies · Physics 2016-04-20 Jonathan Braine , Pierre Gratier , Carsten Kramer , Karl F. Schuster , Fatemeh Tabatabaei , Erwan Gardan

An improved formulation for the X-factor is proposed. The statement that the velocity-integrated radiation temperature of the $\COone$ line, $I(\CO)$, ``counts'' optically thick clumps is quantified using the formalism of \citet{Martin84}…

Astrophysics · Physics 2008-11-26 W. F. Wall

In our Galaxy, the average star formation efficiency is of the order of a few percent. We investigated the high-latitude molecular cloud MBM12 as part of the B-fields and star formation across scales (B-FROST) survey with the Taeduk Radio…

Carbon monoxide (CO) is a poor tracer of H$_{2}$ in the diffuse interstellar medium (ISM), where most of the carbon is not incorporated into CO molecules unlike the situation at higher extinctions. We present a novel, indirect method to…

Astrophysics of Galaxies · Physics 2023-12-18 Raphael Skalidis , Paul F. Goldsmith , Philip F. Hopkins , Sam B. Ponnada

We present the detection analysis of a diffuse molecular cloud at z$_{abs}$=2.4636 towards the quasar SDSS J1513+0352(z$_{em}\,\simeq$ 2.68) observed with the X-shooter spectrograph(VLT). We measure very high column densities of atomic and…

Using the IRAM 30-m telescope, we have obtained 12CO J=1-0 and 2-1 spectral line observations toward the nuclear regions of 15 edge-on, low surface brightness (LSB) spiral galaxies. Our sample comprises extreme late-type LSB spirals with…

Astrophysics · Physics 2009-11-10 Lynn D. Matthews , Yu Gao , Juan M. Uson , Francoise Combes

A 3 $\times$ 3 map of the Galactic Center was made at 9$\arcmin$ resolution and 10$\arcmin$ spacing in the CH $^2\Pi_{1/2}$, J=1/2, F=1-1 transition at 3335 MHz. The CH emission shows a velocity extent that is nearly that of the CO(1-0)…

Astrophysics · Physics 2009-11-13 Loris Magnani , Susan Zelenik , T. M. Dame , B. Engebreth

We present J=2-1, J=3-2, J=4-3 12CO maps as well as J=2-1, J=3-2 13CO and 492 GHz [CI] measurements of the central region in M51. The distribution of CO is strongly concentrated towards the spiral arms. The center itself is poor in, though…

Astrophysics · Physics 2009-11-11 F. P. Israel , R. P. J. Tilanus , F. Baas

We present moderate (1'') and high resolution (0.2'') observations of the CO(2-1) emission at 43 GHz, and radio continuum emission at 1.47 GHz, from the z=4.7 QSO BRI 1202-0725 and the z=4.4 QSO BRI 1335--0417 using the Very Large Array.…

Astrophysics · Physics 2009-11-07 C. L. Carilli , K. Kohno , R. Kawabe , K. Ohta , C. Henkel , K. Menten , M. Yun , A. Petric , Y. Tutui

We have mapped the Orion-A Giant Molecular Cloud in the CO (J=4-3) line with the Tsukuba 30-cm submillimeter telescope.The map covered a 7.125 deg^2 area with a 9' resolution, including main components of the cloud such as Orion Nebula,…

We conducted high-sensitivity, high-velocity resolution CO(1-0) observations in a region containing a portion of the diffuse molecular cloud MBM 53 to determine whether weak CO emission was present. The results of our observations increase…

Astrophysics of Galaxies · Physics 2017-10-20 Emmanuel Donate , Loris Magnani

L1551 is chosen because it is relatively isolated in the Taurus molecular cloud shielded from FUV photons, providing an ideal environment for studying the target properties. Our observations cover ~40'x40' with resolution ~30", which are…

We have studied the properties of molecular clouds in the second quadrant of the Milky Way Mid-plane from l$=$104$.\!\!^{\circ}$75 to l$=$119$.\!\!^{\circ}$75 and b$=-$5$.\!\!^{\circ}$25 to b$=$5$.\!\!^{\circ}$25 using the $^{12}$CO,…

Astrophysics of Galaxies · Physics 2021-04-28 Yuehui Ma , Hongchi Wang , Chong Li , Lianghao Lin , Yan Sun , Ji Yang

In our local Galactic neighborhood, molecular clouds are best studied using a combination of dust measurements, to determine robust masses, sizes and internal structures of the clouds, and molecular-line observations to determine cloud…

Astrophysics of Galaxies · Physics 2020-02-19 Jan Forbrich , Charles J. Lada , Sébastien Viaene , Glen Petitpas

We present the results of N2H+(1-0) observations of 35 dense molecular cloud cores from the northern and southern hemispheres where massive stars and star clusters are formed. Line emission has been detected in 33 sources, for 28 sources…

Astrophysics · Physics 2009-11-07 L. Pirogov , I. Zinchenko , P. Caselli , L. E. B. Johansson , P. C. Myers

We have carried out a blind search in the general direction of the Galactic Anticenter for absorption of the Cosmic Microwave Background (CMB) radiation near 4.83 GHz by molecular clouds containing gaseous ortho-formaldehyde (H_2CO). The…

Astrophysics · Physics 2008-11-26 Monica Ivette Rodriguez , Ronald J. Allen , Laurent Loinard , Tommy Wiklind

The chemical structure of neutral clouds in low metallicity environments is examined with particular emphasis on the H to H_2 and C+ to CO transitions. We observed near-IR H_2 lines and the CO J=1-0 line from 30 Doradus and N159/N160 in the…

Astrophysics · Physics 2014-10-13 Soojong Pak , D. T. Jaffe , Ewine F. van Dishoeck , L. E. B. Johansson , R. S. Booth

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
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