Self-sustaining galactic winds in spiral galaxies with starburst nuclei

Beckman, John E.
Bibliographical reference

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. 385-390.

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1988
Number of authors
1
IAC number of authors
1
Citations
2
Refereed citations
2
Description
In the circumnuclear zones of the disks of some spirals there is an absence of neutral interstellar hydrogen. A model is devised in which gaseous outflow is sustained by the combined action of massive stars in these zones. The energy requirement, which implies driving out the gas against gravity, can be satisfied if 10 percent or more of the gas condenses into massive stars. A problem is efficient coupling of energy into outflow without disrupting the molecular gas. It is shown that combined stellar winds can just satisfy the energy and momentum requirements for outflow, as can supernovas. Dust in the molecular clouds would permit radiation to couple strongly to the gas. All these effects are present. Observable consequences should be: (1) expansion with velocities of tens of km/s near the nuclei of some galaxies, (2) absence of neutral gas near the centers of poststarburst galaxies, and (3) metallicity gradients, with residual gas near the nucleus being metal-rich and a peak of stellar metallicity in a ring whose distance from the nucleus depends on the age of the burst.