J. Franco et al., Decreasing density gradients in circumnuclear HII regions of barred galaxies NGC 1022, NGC 1326, and NGC 4314, ASTROPHYS J, 544(1), 2000, pp. 277-282
A reanalysis of the radio continuum emission from circumnuclear regions of
the barred galaxies NGC 1022, NGC 1326, and NGC 4314 is presented. The spat
ial distributions of Ha and radio continuum are similar and suggest the exi
stence of several giant H II regions in the circumnuclear zone. The spectra
l indices of the H 11 regions, obtained with similar angular resolution and
at three different wavelengths, indicate that in all three galaxies alpha
(6)(2) > -0.1. This result suggests the existence of giant H II regions wit
h decreasing density gradients. The average density stratifications of thes
e H 11 regions could be approximated by power laws of the form n(e) proport
ional to r(-omega), with exponents in the range 1.6 < omega < 2.4.