Bibcode
Munoz-Tunon, C.; Beckman, John E.
Referencia bibliográfica
IN: Mass outflows from stars and galactic nuclei; Proceedings of the Second Torino Workshop, Turin, Italy, May 4-8, 1987 (A88-54076 24-90). Dordrecht, Kluwer Academic Publishers, 1988, p. 391-395.
Fecha de publicación:
0
1988
Número de citas
0
Número de citas referidas
0
Descripción
The radial hydrogen (H2 + HI) distribution in spirals takes two forms:
with a density peak at the nucleus or with a circular 'hole' around it.
Spectral and photometric properties of selected spirals are examined,
and cases of expansion in the circumnuclear gas, as well as ring
structures in gas and stars are found. The correlation between absence
of central gas and size of nuclear bulge (Sa galaxies have a lower bulge
gas:stars ratio than Sc galaxies), plus the presence of LINERS in the
interstellar medium close to the nucleus indicate probable outflow
during starbursts. In NGC 6946, the outflow in H-alpha and N II was
observed at velocities near 1000 km/s. In NGC 1068 and NGC 4736
expanding rings are found between 1 or 2 kpc, and in NGC 7331 a central
LINER plus a static ring are observed at 4 kpc. Outflow from the nucleus
is probably a common feature of the formation of central regions of
spirals.