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Related papers: Atomic Carbon Is a Temperature Probe in Dark Cloud…

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Observations of dark cloud cores have been carried out in the mid-infrared using ISOCAM and in the far-infrared using ISOPHOT, both aboard the Infrared Space Observatory. The cores are in most cases detected in emission at 200 and 170…

Astrophysics · Physics 2007-05-23 Aurore Bacmann , Philippe Andre , Derek Ward-Thompson

We examine the fine structure lines $^{3}P_{1}\to $$^{3}P_{0}$ (492 GHz) and $ ^{3}P_2\to $$^{3}P_1$ (809 GHz) of neutral atomic carbon as bulk molecular gas mass tracers and find that they can be good and on many occasions better than $…

Astrophysics · Physics 2009-11-10 Papadopoulos P. Padeli , Thi Wing-Fai , Viti Serena

We present spectral data cubes of the [CI] 809GHz, 12CO 115GHz, 13CO 110GHz and HI 1.4GHz line emission from an 1 square degree region along the l = 328{\deg} (G328) sightline in the Galactic Plane. Emission arises principally from gas in…

Determining temperatures in molecular clouds from ratios of CO rotational lines or from ratios of continuum emission in different wavelength bands suffers from reduced temperature sensitivity in the high-temperature limit. In theory, the…

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

The properties of the ices that form in dense molecular clouds represent an important set of initial conditions in the evolution of interstellar and preplanetary matter in regions of active star formation. Of the various spectral features…

Solar and Stellar Astrophysics · Physics 2011-02-11 D. C. B. Whittet , A. M. Cook , J. E. Chiar , Y. J. Pendleton , S. S. Shenoy , P. A. Gerakines

Emission from the 492 GHz CI tranition was detected towards the dark cloud D478 in M31. Using existing 12CO and 13CO measurements, models for the gas properties of D478 are discussed. The observed CO and C line ratios can be explained by…

Astrophysics · Physics 2007-05-23 F. P. Israel , R. P. J. Tilanus , F. Baas

Models predict that atomic carbon occurs at the surface and in the process of the formation of molecular clouds, making its fine structure transitions a diagnostic of cloud formation. We study the distribution of atomic carbon in a small…

Astrophysics of Galaxies · Physics 2025-04-16 V. Ossenkopf-Okada , A. Karska , M. Benedettini , D. Colombo , R. Simon

Giant molecular clouds contain supersonic turbulence that can locally heat small fractions of gas to over 100 K. We run shock models for low-velocity, C-type shocks propagating into gas with densities between 10^3 and 10^5 cm^(-3) and find…

Astrophysics of Galaxies · Physics 2016-08-23 A. Pon , M. J. Kaufman , D. Johnstone , P. Caselli , F. Fontani , M. J. Butler , I. Jiménez-Serra , A. Palau , J. C. Tan

We present the results of an extensive observational study of the active star-forming complex W51 that was observed in the J=2-1 transition of the 12CO and 13CO molecules over a 1.25 deg x 1.00 deg region with the University of Arizona…

Astrophysics of Galaxies · Physics 2015-05-19 Miju Kang , John H. Bieging , Craig A. Kulesa , Youngung Lee , Minho Choi , William L. Peters

This paper presents results from modelling 450 micron and 850 micron continuum and HCO+ line observations of three distinct cores of an infrared dark cloud (IRDC) directed toward the W51 GMC. In the sub-mm continuum these cores appear as…

Astrophysics · Physics 2009-11-11 C. W. Ormel , R. F. Shipman , V. Ossenkopf , F. P. Helmich

We have used a laser heterodyne spectrometer to resolve the emission line profile of the 63 micron 3P1 - 3P2 fine-structure transition of O I at two locations in M42. Comparison of the peak antenna temperature with that of the 158 micron C…

Astrophysics · Physics 2009-10-28 R. T. Boreiko , A. L. Betz

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,…

Ionized carbon is the main gas-phase reservoir of carbon in the neutral diffuse interstellar medium and its 158 micron fine structure transition [CII] is the most important cooling line of the diffuse interstellar medium (ISM). We combine…

We present fully-sampled maps of 461 GHz CO (4-3), 807 GHz CO (7-6), and 492 GHz [CI] (3P1-3P0) emission from the inner 3 degrees of the Galactic Center region taken with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO)…

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

We used the Atacama Pathfinder Experiment (APEX) 12 m telescope to observe the J_KaKc=3_03-2_02, 3_22-2_21, and 3_21-2_20 transitions of para-H_2CO at 218 GHz simultaneously to determine kinetic temperatures of the dense gas in the central…

Astrophysics of Galaxies · Physics 2015-06-12 Y. Ao , C. Henkel , K. M. Menten , M. A. Requena-Torres , T. Stanke , R. Mauersberger , S. Aalto , S. Muehle , J. Mangum

Analysis of interstellar absorption lines observed in high-resolution {\em HST} spectra of nearby stars provides temperatures, turbulent velocities, and kinetic properties of warm interstellar clouds. Previous studies identified 15 warm…

Astrophysics of Galaxies · Physics 2022-08-31 Jeffrey L. Linsky , Seth Redfield , Diana Ryder , Adina Chasan-Taber

Far-infrared continuum data from the {\it COBE}/{\it DIRBE} instrument were combined with Nagoya 4-m $\cOone$ spectral line data to infer the multiparsec-scale physical conditions in the Orion$ $A and B molecular clouds, using…

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

We have mapped the [C I] emission at 492 GHz toward the supernova remnant Cas A. We detect [C I] emission from the periphery of the diffuse Photon Dominated Region (PDR) covering the disk of Cas A, as traced by the carbon recombination…

Astrophysics · Physics 2009-11-11 B. Mookerjea , N. G. Kantharia , D. A. Roshi , M. Masur , ;

The primary radiation generated in the central continuum-forming region of Active Galactic Nuclei can be reprocessed by very dense, small-scale clouds that are optically-thin to Thomson scattering. In spite of the extreme conditions…

Astrophysics · Physics 2015-06-24 Z. Kuncic , A. Celotti , M. J. Rees