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Journal ArticleDOI

Far Infrared and Submillimeter Emission from Galactic and Extragalactic Photo-Dissociation Regions

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TLDR
In this article, the effects of metallicity and cloud extinction on the predicted line intensities were examined for PDR models with densities over the range n=10^1-10^7 cm^-3.
Abstract
Photodissociation Region (PDR) models are computed over a wide range of physical conditions, from those appropriate to giant molecular clouds illuminated by the interstellar radiation field to the conditions experienced by circumstellar disks very close to hot massive stars. These models use the most up-to-date values of atomic and molecular data, the most current chemical rate coefficients, and the newest grain photoelectric heating rates which include treatments of small grains and large molecules. In addition, we examine the effects of metallicity and cloud extinction on the predicted line intensities. Results are presented for PDR models with densities over the range n=10^1-10^7 cm^-3 and for incident far-ultraviolet radiation fields over the range G_0=10^-0.5-10^6.5, for metallicities Z=1 and 0.1 times the local Galactic value, and for a range of PDR cloud sizes. We present line strength and/or line ratio plots for a variety of useful PDR diagnostics: [C II] 158 micron, [O I] 63 and 145 micron, [C I] 370 and 609 micron, CO J=1-0, J=2-1, J=3-2, J=6-5 and J=15-14, as well as the strength of the far-infrared continuum. These plots will be useful for the interpretation of Galactic and extragalactic far infrared and submillimeter spectra observable with ISO, SOFIA, SWAS, FIRST and other orbital and suborbital platforms. As examples, we apply our results to ISO and ground based observations of M82, NGC 278, and the Large Magellenic Cloud.

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Journal ArticleDOI

THE PRODUCTION OF H i IN PHOTODISSOCIATION REGIONS AND A COMPARISON WITH CO (1-0) EMISSION

TL;DR: In this article, the authors used previously developed models for photodissociation regions (PDRs) to compute the intensities of these H I and CO (1-0) lines as a function of the total volume density n in the cloud and the far-ultraviolet (FUV) flux G0 incident on it and present the results in units familiar to observers.
Journal ArticleDOI

THE LOCAL [C ii] 158 μm EMISSION LINE LUMINOSITY FUNCTION

TL;DR: In this article, the authors presented the first time the local [C ii] 158 μm emission line luminosity function measured using a sample of more than 500 galaxies from the Revised Bright Galaxy Sample.
Journal ArticleDOI

Submillimeter CO Line Emission from Orion

TL;DR: In this article, the authors used on-the-fly mapping and position switching techniques to obtain images of an 8 square arcmin region around the Orion KL source with angular resolutions of 13'' and 18''.
Journal ArticleDOI

The cooling of atomic and molecular gas in DR21

TL;DR: In this paper, the authors used the KOSMA 3m telescope to map the core of the Galactic star forming region DR 21/DR 21 (OH) in the Cygnus X region in two fine structure lines of atomic carbon CI and four mid-$J$ transitions of CO and $^{13}$CO, and CS $J=7\TO6$.
Journal ArticleDOI

Warm gas towards young stellar objects in Corona Australis - Herschel/PACS observations from the DIGIT key programme

TL;DR: In this paper, the effects of external irradiation on the chemistry and physics in the protostellar envelope around low-mass young stellar objects are poorly understood, and a deconvolution algorithm is developed to separate the point-source emission from the extended emission.
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