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CSENV: A code for the chemistry of CircumStellar ENVelopes
Gary A. Mamon
Institut d'Astrophysique de Paris
and
Observatoire de Paris
Abstract:
CSENV is a code that computes the chemical abundances for a desired set of
species as a function of radius in a stationary, non-clumpy, CircumStellar
ENVelope.
The chemical species can be atoms, molecules, ions, radicals, molecular ions,
and/or their specific quantum states.
Collisional ionization or excitation can be incorporated through the proper
chemical channels.
The chemical species interact with one another and can are subject to
photo-processes (dissociation of molecules, radicals, and molecular ions as
well as ionization of all species). Cosmic ray ionization can be included.
Chemical reaction rates are specified with possible activation temperatures
and additional power-law dependences.
Photo-absorption cross-sections vs. wavelength, with appropriate thresholds,
can be specified for each species, while for H2+ a photoabsorption
cross-section is provided as a function of wavelength and temperature.
The photons originate from both the star and the external interstellar
medium. The chemical species are shielded from the photons by circumstellar
dust, by other species and by themselves (self-shielding).
Shielding of continuum-absorbing species by these species (self and mutual
shielding), line-absorbing species, and dust varies with radial optical
depth.
The envelope is spherical by default, but can be made bipolar with an opening
solid-angle that varies with radius. In the non-spherical case, no provision
is made for photons penetrating the envelope from the sides. The envelope is
subject to a radial outflow (or wind), constant velocity by default, but the
wind velocity can be made to vary with radius. The temperature of the
envelope is specified (and thus not computed self-consistently).
Subject headings: astrochemistry, circumstellar matter, ISM: molecules
Latest Version: 6.0 (1999 March 22)
Archived: 2001 April 20
Papers: (multiple: representative)
Glassgold, Mamon & Huggins, 1991, ApJ 373, 254
Language: Fortran 77
Platform: SunOS 4.1.3, OSF 4.0, Linux RedHat 6.0
External Explanatory Page(s):
http://www.iap.fr/users/gam/csenv.html
Source Code: (latest, external)
ftp://ftp.iap.fr/pub/from_users/gam/csenv.tar
Source Code: (archived, local)
csenv.tar.gz