P. Pismis et E. Moreno, ON THE FORMATION OF SPIRAL AND RING-SHAPED FEATURES AROUND GALACTIC NUCLEI, The Astronomical journal, 106(5), 1993, pp. 1734-1742
This work is an improvement upon an earlier study about the formation
of spiral features in galactic nuclei, starting again from an ejection
mechanism [Pismis & Moreno, Afz., 20, 7 (1984)]. We now consider a se
miballistic treatment to follow the motion of a mass element ejected f
rom a nuclear region, and find the locus at a given time, and its asso
ciated velocity field, on which the ejected elements are distributed.
Given enough time, the interaction of the ejecta with the gas in the g
alactic disk drives a spiral feature into a ring. After considering so
me properties emerging from the model, we apply it to the galaxy NGC 4
736.