Bibcode
DOI
Contini, Marcella; Prieto, M. A.; Viegas, Sueli M.
Bibliographical reference
The Astrophysical Journal, Volume 505, Issue 2, pp. 621-633.
Advertised on:
10
1998
Journal
Citations
36
Refereed citations
30
Description
Simultaneous modeling of the line and continuum emission from the
nuclear region of the Circinus galaxy is presented. Composite models
that include the combined effect of shocks and photoionization from the
active center and from the circumnuclear star-forming region are
considered. The effects of dust reradiation, bremsstrahlung from the
gas, and synchrotron radiation are treated consistently. Models that fit
the continuum energy distribution of Circinus are used to constrain all
possible models suitable for the line emission; they are all, together,
aimed to converge to a most probable representation of the central
emission region of Circinus. The proposed model accounts for two
important observational features. First, the high obscuration of
Circinus central source is produced by high-velocity and dense clouds
with characteristic dust-to-gas ratios above 10^-12. Their large
velocities, up to 1500 km s^-1, place them very close to the active
center. Second, the derived size of the line-emitting region (~13 pc) is
well in agreement with the observed limits for the coronal (<10 pc)
and narrow-line regions (~30 pc) of Circinus.