Abstract
We examine observational characteristics of multiphase turbulent flows in the diffuse interstellar medium (ISM) using a synthetic radiation field of atomic and molecular lines. We consider the multiphase ISM, which is formed by thermal instability under the irradiation of UV photons with moderate visual extinction AV ∼ 1. Radiation field maps of C+, C 0, and CO line emissions were generated by calculating the non-local thermodynamic equilibrium (non-LTE) level populations from the results of high-resolution hydrodynamic simulations of diffuse ISM models. By analyzing the synthetic radiation field of carbon lines of [C II] 158 μm, [C I] 3P2-3P1 (809 GHz), 3P1-3P0 (492 GHz), and CO rotational transitions, we found a high ratio between the lines of high- and low-excitation energies in the diffuse multiphase ISM. This shows that simultaneous observations of the lines of warm- and cold-gas tracers will be useful in examining the thermal structure, and hence the origin, of diffuse interstellar clouds.
Original language | English |
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Pages (from-to) | 849-859 |
Number of pages | 11 |
Journal | Astrophysical Journal |
Volume | 657 |
Issue number | 2 I |
DOIs | |
Publication status | Published - 2007 Mar 10 |
Externally published | Yes |
Keywords
- ISM: clouds
- ISM: molecules
- Radio lines: ISM
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science