Nearby molecular clouds. II - The Cepheus flare and the effect of field stars on galaxy counts
F. Lebrun;
ApJ, 1986, 306, 16
ABSTRACT:Two large-scale CO surveys have been performed in Cepheus and in Aquila, Resulting in
the first case in the discovery of one of the major molecular complexes
close to the sun.
Cepheus looks very similar to Orion, the typical giant
molecular cloud in the solar neighborhood.
In contrast, only a few small clouds
have been found in Aquila.
These results indicate that the Lick galaxy
counts catalog, taken at face value, is not a reliable gas tracer.
It is shown
that the number density of galaxies depends as much on the field star density
as on the gas density, as traced by the 21 cm line.
The net result is that the
probability of detecting a galaxy in a star field decreases exponentially with the
star density.
A correction for this effect is proposed, and leads to a new
picture of the gas distribution in the solar neighborhood in very good
agreement with large-scale CO observations.
KEYWORDS: galactic structure, interstellar gas, mass distribution, molecular clouds, star distribution, astronomical maps, carbon monoxide, cosmic dust, cosmic gases, cosmic rays, flares, solar system
PERSOKEY:co, h2, supershell, ,
CODE: lebrun86