Temperatures and their variation within interstellar H I structures
C. Heiles;
ApJ, 1982, 262, 135
ABSTRACT:Recent H I absorption surveys are used to derive H I temperatures T(H I) and their variation within a number of H I shells.
In these shells T(H I) is
in the domain of cold, neutral gas, and ranges down to 35 K; densities are
about 2/cu cm.
Outside the relatively dense shells, H I temperatures are
much higher.
It is considered whether temperatures increase toward the
edges of H I shells; no systematic trend is apparent.
Low-energy cosmic rays
are probably powerful enough to account for the observed H I temperatures
in shells associated with regions of enhanced synchrotron
emission.
Low-energy X-rays are probably not powerful enough to heat the gas in the Eridanus H
I shell.
KEYWORDS: hydrogen clouds, interstellar matter, milky way galaxy, radio sources (astronomy), astronomical photography, synchrotron radiation
PERSOKEY:h_i, ,
CODE: heiles82