Bibcode
Beckman, J. E.; Munoz-Tunon, C.; Prieto, M.; Battaner, E.; Sanchez Saavedra, M. L.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 161, no. 1, June 1986, p. 55-60.
Advertised on:
6
1986
Citations
13
Refereed citations
11
Description
Using the H-II region H-alpha emission detected in high-resolution long
slit spectra of the normal spiral NGC 6946 out to 6 kpc from the center,
and along 8 radii equally spaced in angle, velocity curves of the
circumnuclear zone are obtained. The curves show that the radial
velocity gradient, and the limiting radial velocity along the minor axis
are much greater than those along the major axis, in contrast to models
in which rotational velocities predominate. The present results and
previous observations of CO suggest that the central gas of NGC 6946 is
in a state of expansion, with the driving force for this expansion
coming from the 10,000 O5 stars known to be present within the disk
component of the zone. Both the supernovae model and the model with
radiative coupling to the gas via the copious dust are found to satisfy
the energy and momentum requirements, and both may be operating to drive
the observed wind.