Gaches, Brandt A. L., Bialy, Shmuel, Bisbas, Thomas G., Padovani, Marco, Seifried, Daniel and Walch, Stefanie (2022). Cosmic-ray-induced H-2 line emission Astrochemical modeling and implications for JWST observations. Astron. Astrophys., 664. LES ULIS CEDEX A: EDP SCIENCES S A. ISSN 1432-0746
Full text not available from this repository.Abstract
Context. It has been proposed that H-2 near-infrared lines may be excited by cosmic rays and thus allow for a determination of the cosmic-ray ionization rate in dense gas. One-dimensional models show that measuring both the H-2 gas column density and H-2 line intensity enables a constraint on the cosmic-ray ionization rate as well as on the spectral slope of low-energy cosmic-ray protons in the interstellar medium. Aims. We aim to investigate the impact of certain assumptions regarding the H-2 chemical models and interstellar medium density distributions on the emission of cosmic-ray-induced H-2 emission lines. This is of particular importance for utilizing observations of these lines with the James Webb Space Telescope to constrain the cosmic-ray ionization rate. Methods. We compare the predicted emission from cosmic-ray-induced, rovibrationally excited H-2 emission lines for different one-and three-dimensional models with varying assumptions regarding the gas chemistry and density distribution. Results. We find that the model predictions of the H-2 line intensities for the (1-0)S(0), (1-0)Q(2), (1-0)O(2), and (1-0)O(4) transitions at 2.22, 2.41, 2.63, and 3.00 mu m, respectively, are relatively independent of the astro-chemical model and the gas density distribution when compared against the H-2 column density, making them robust tracers of the cosmic-ray ionization rate. Conclusions. We recommend the use of rovibrational H-2 line emission in combination with estimations of the cloud's H-2 column density to constrain the ionization rate and the spectrum of low-energy cosmic rays.
Item Type: | Journal Article | ||||||||||||||||||||||||||||
Creators: |
|
||||||||||||||||||||||||||||
URN: | urn:nbn:de:hbz:38-685167 | ||||||||||||||||||||||||||||
DOI: | 10.1051/0004-6361/202244090 | ||||||||||||||||||||||||||||
Journal or Publication Title: | Astron. Astrophys. | ||||||||||||||||||||||||||||
Volume: | 664 | ||||||||||||||||||||||||||||
Date: | 2022 | ||||||||||||||||||||||||||||
Publisher: | EDP SCIENCES S A | ||||||||||||||||||||||||||||
Place of Publication: | LES ULIS CEDEX A | ||||||||||||||||||||||||||||
ISSN: | 1432-0746 | ||||||||||||||||||||||||||||
Language: | English | ||||||||||||||||||||||||||||
Faculty: | Unspecified | ||||||||||||||||||||||||||||
Divisions: | Unspecified | ||||||||||||||||||||||||||||
Subjects: | no entry | ||||||||||||||||||||||||||||
Uncontrolled Keywords: |
|
||||||||||||||||||||||||||||
URI: | http://kups.ub.uni-koeln.de/id/eprint/68516 |
Downloads
Downloads per month over past year
Altmetric
Export
Actions (login required)
![]() |
View Item |