Bibcode
Munoz-Tunon, C.; Vilchez, J. M.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 186, no. 1-2, Nov. 1987, p. 25-29.
Advertised on:
11
1987
Citations
4
Refereed citations
4
Description
A complex kinematical structure is inferred from the analysis of high
resolution spectra of the nuclear region of the galaxy NGC 6946. The
spatial resolution of the observations allowed the authors to resolve a
dynamically inhomogeneous area of approximately 10 arcseconds in
diameter, very close to the centre of the galaxy. Within this region the
emission lines show non-gaussian profiles which are generally split into
at least two main components, differing in velocity by approximately 50
km s-1. These line profiles show an intricate structure in
both the Hα and the [N II] lines, indicating that self-absorption
effects in Hα can be ruled out. A simple interpretation of the
kinematical structure in terms of a rotational velocity curve alone does
not appear to be realistic. An interpretation based on stellar winds
plus supernova explosions as proposed by Beckman et al. (1986), is
preferred rather than a model with purely gravitationally coupled
motions. The authors examine this solution in the light of the
particularly rich star formation history of NGC 6946.