Modelling galactic spectra - I. A dynamical model for NGC 3258

Autor(en)

Veronique de Bruyne, Sven de Rijcke, Herwig B. Dejonghe, Werner Zeilinger

Abstrakt

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(en)

Institut für Astrophysik

Externe Organisation(en)

Ghent University

Journal

Monthly Notices of the Royal Astronomical Society

Band

349

Seiten

440-460

Anzahl der Seiten

21

ISSN

0035-8711

Publikationsdatum

2004

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2dd6ea1c-8c5e-47d6-ae4f-622563225561