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Photodissociation Regions - Part Two - a Model for the Orion Photodissociation Region
The Astrophysical Journal, 1985 On a construit un modele pour la region de photodissociation d'Orion. Il permet de rendre compte de l'emission observee dans les raies de structure fine de O I a 63 μm et a 145 μm, de C I a 609 μm et C II a 158 μm et des raies rotationnelles de CO. Il explique egalement l'emission H 2 1-0 S(1) etendue, les raies de recombinaison du carbone et la raie ...
A. G. G. M. Tielens, D. Hollenbach
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Carbon Chemistry in Photodissociation Regions [PDF]
Proceedings of the International Astronomical Union, 2005 We present recent results on the carbon chemistry in photodissociation regions. We show that carbon chains and rings (CCH, c-C$_3$H$_2$ and C$_4$H) are tightly spatially correlated with each other, and with the mid-infrared emission due to PAHs (7 and 15 $\mu$m), mapped by ISOCAM.
M. Gerin +8 more
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The Astrophysical Journal Supplement Series, 2022 We present an efficient heating/cooling method coupled with chemistry and UV radiative transfer that can be applied to numerical simulations of the interstellar medium (ISM).
Jeong-Gyu Kim +3 more
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Unveiling the remarkable photodissociation region of Messier 8 [PDF]
Astronomy & Astrophysics, 2018 Aims. Messier 8 (M8) is one of the brightest HII regions in the sky. We collected an extensive dataset comprising multiple sub- millimeter spectral lines from neutral and ionized carbon and from CO. Based on this dataset, we aim to understand the morphology of M8 and that of its associated photodissociation region (PDR) and to carry out a quantitative ...
Tiwari, M. +7 more
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Sagittarius B1: A Patchwork of H ii Regions and Photodissociation Regions [PDF]
The Astrophysical Journal, 2021 Abstract Sgr B1 is a luminous H ii region in the Galactic center immediately next to the massive star-forming giant molecular cloud Sgr B2 and apparently connected to it from their similar radial velocities. In 2018 we showed from SOFIA FIFI-LS observations of the [O iii] 52 and 88 μm lines that there is no central exciting star cluster ...
Janet P. Simpson +4 more
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Time-Dependent Photodissociation Regions [PDF]
The Astrophysical Journal, 1995 We present theoretical models of the time-dependent thermal and chemical structure of molecular gas suddenly exposed to far-ultraviolet (FUV) (6 eV less than hv less than 13.6 eV) radiation fields and the consequent time- dependent infrared emission of the gas. We focus on the response of molecular hydrogen for cloud densities ranging from n = 10(exp 3)
David Hollenbach, Antonella Natta
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The Astrophysical Journal, 2023 Photodissociation regions (PDRs) illuminated by high temperature ( T > 10 ^4 K) radiation fields display characteristic optical to midinfrared spectral features: emission bands that cluster around the blue limits of hydrogen series, an extended red ...
Frédéric Zagury
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A Magnetically Supported Photodissociation Region in M17
The Astrophysical Journal, 2007 The southwestern (SW) part of the Galactic H II region M17 contains an obscured ionization front that is most easily seen at infrared and radio wavelengths. It is nearly edge-on, thus offering an excellent opportunity to study the way in which the gas changes from fully ionized to molecular as radiation from the ionizing stars penetrates into the gas ...
Pellegrini, E. W. +8 more
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On the Relationship Between Molecular Hydrogen and Carbon Monoxide Abundances in Molecular Clouds [PDF]
, 2010 The most usual tracer of molecular gas is line emission from CO. However, the reliability of that tracer has long been questioned in environments different from the Milky Way. We study the relationship between H2 and CO abundances using a fully dynamical
Blitz +62 more
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