The Cosmic-Ray Ionization Rate in the Galactic Disk, as Determined from Observations of Molecular Ions
نویسندگان
چکیده
منابع مشابه
The galactic cosmic ray ionization rate.
The chemistry that occurs in the interstellar medium in response to cosmic ray ionization is summarized, and a review of the ionization rates that have been derived from measurements of molecular abundances is presented. The successful detection of large abundances of H(3)(+) in diffuse clouds and the recognition that dissociative recombination of H(3)(+) is fast has led to an upward revision o...
متن کاملORFEUS-I Observations of Molecular Hydrogen in the Galactic Disk
We present measurements of interstellar H2 absorption lines in the continuum spectra of seven early-type stars in the Galactic disk at distances between 1 and 4 kpc. Five of these stars provide lines of sight through the Sagittarius spiral arm. The spectra, obtained with the Berkeley EUV/FUV spectrometer on the ORFEUS telescope in 1993 September, have a resolution of 3000 and statistical signal...
متن کاملDetermining the cosmic ray ionization rate in dynamically evolving clouds
The ionization fraction is an important factor in determining the chemical and physical evolution of star forming regions. In the dense, dark starless cores of such objects, the ionization rate is dominated by cosmic rays; it is therefore possible to use simple analytic estimators, based on the relative abundances of different molecular tracers, to determine the cosmic ray ionization rate. This...
متن کاملCosmic-ray ionization of molecular clouds
Context. Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. Aims. The purpose of this work is to explore the possibility that a low-energy component of cosmic-rays, not directly measurable from the Earth, can account for the discrepancy between the ionization rate measured in diffuse and dense interste...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2017
ISSN: 1538-4357
DOI: 10.3847/1538-4357/aa6d68