Modelling galactic spectra - I. A dynamical model for NGC 3258
- Author(s)
- Veronique de Bruyne, Sven de Rijcke, Herwig B. Dejonghe, Werner Zeilinger
- Abstract
We present a method to analyse absorption-line spectra of a galaxy designed to determine the stellar dynamics and the stellar populations by a direct fit to the spectra. This paper is the first to report on the application of the method to data. The modelling results in the knowledge of distribution functions that are sums of basis functions. The practical implementation of the method is discussed and a new type of basis function is introduced. With this method, a dynamical model for NGC 3258 is constructed. This galaxy can be modelled successfully with a potential containing 30 per cent dark matter within lr e with a mass of 1.6 × 1011 M?. The total mass within 2re is estimated as 5 × 1011 M?, containing 63 per cent dark matter. The model is isotropic in the centre, is radially anisotropic between 0.2 and 2 kpc (0.88re), and becomes tangentially anisotropic further on. The photometry reveals the presence of a dust disc near the centre.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Ghent University
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 349
- Pages
- 440-460
- No. of pages
- 21
- ISSN
- 0035-8711
- Publication date
- 2004
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/2dd6ea1c-8c5e-47d6-ae4f-622563225561