Spiral stellar density waves and the flattening of abundance gradients in the warm gas component of spiral galaxies

Author(s)
E. I. Vorobyov
Abstract

Motivated by recent observations of plateaus and minima in the radial abundance distributions of heavy elements in the Milky Way and some other spiral galaxies, we propose a dynamical mechanism for the formation of such features around corotation. Our numerical simulations show that the non-axisymmetric gravitational field of spiral density waves generates cyclone and anticylone gas flows in the vicinity of corotation. The anticyclones flatten the pre-existing negative abundance gradients by exporting many more atoms of heavy elements outside corotation than importing inside it. This process is very efficient and forms plateaus of several kiloparsec in size around corotation after two revolution periods of a galaxy. The strength of anticyclones and, consequently, the sizes of plateaus depend on the pitch angle of spiral arms and are expected to increase along the Hubble sequence.

Organisation(s)
Department of Astrophysics
External organisation(s)
University of Toronto, University of Western Ontario
Journal
Monthly Notices of the Royal Astronomical Society
Volume
370
Pages
1046-1054
No. of pages
9
ISSN
0035-8711
DOI
https://doi.org/10.1111/j.1365-2966.2006.10550.x
Publication date
08-2006
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics
Keywords
ASJC Scopus subject areas
Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/b6d12152-91c5-4bb4-8d83-cd2312210fbb