Bibcode
Beckman, J. E.; Zurita, A.; Rozas, M.
Referencia bibliográfica
in Galaxy Disks and Disk Galaxies, proceeding of a conference held in Rome, Italy, June 12-16, 2000 at the Pontifical Gregorian University and sponsored by the Vatican Observatory. ASP Conference Series, Vol. 230. Edited by José G. Funes, S. J. and Enrico Maria Corsini. San Francisco: Astronomical Society of the Pacific. ISBN: 1-58381-063-3, 2001, pp. 299-304
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2001
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Descripción
We examine using numerical examples and conservative assumptions, the
consequences of the fractal structure of the interstellar medium in a
disk galaxy in permitting the propagation of the ionizing radiation
emitted by its massive stellar population. We compare the Strömgren
sphere in a homogeneous medium with its equivalent in a clumpy medium,
taking densities typical of HII regions, to show that there is always a
fractional escape of Lyman continuum photons from an HII region, and
that this fraction should increase for regions with high luminosities.
The calculation is extended to deal with a clumpy medium at densities
typical of the diffuse interstellar gas in disks, showing how
propagation over kpc scales from OB associations is in no way ruled out.
Finally, showing that at densities typical of the IGM clumpiness should
play a less critical role, we estimate the volume and mass of gas around
a Milky Way sized galaxy which should be ionized by photons escaping
from its disk, and draw a parallel with recent results from high-z
galaxies.