Document Type
Article
Publication Date
9-17-2008
Abstract
Aims. We have studied the bulge and the disk kinematics of the giant low surface brightness galaxy ESO 323-G064 in order to investigate its dynamical properties and the radial mass profile of the dark matter (DM) halo. Methods. We observed the galaxy with integral field spectroscopy (VLT/VIMOS, in IFU configuration), measured the positions of the ionized gas by fitting Gaussian functions to the [O III] λλ4959,5007 and Hβ emission lines, and fit stellar templates to the galaxy spectra to determine velocity and velocity dispersions. We modeled the stellar kinematics in the bulge with spherical Isotropie Jeans models and explored the implications of self consistent and dark matter scenarios for NFW and pseudo isothermal halos. Results. In the bulge-dominated region, r < 5″, the emission lines show multi-peaked profiles. The disk dominated region of the galaxy, 13″ < r < 30″, exhibits regular rotation, with a flat rotation curve that reaches 248 ± 6 km s-1. From this we estimate the total barionic mass to be Mbar ∼ 1.9 × 1011 M ⊙ and the total DM halo mass to be MDM ∼ 4.8 × 1012 M⊙. The stellar velocity and velocity dispersion have been measured only in the innermost ≈5″ of the bulge, and reveal a regular rotation with an observed amplitude of 140 km s -1 and a central dispersion of cr = 180 km s-1. Our simple Jeans modeling shows that dark matter is needed in the central 5″ to explain the kinematics of the bulge, for which we estimate a mass of ≈(7 ±3) × 1010 M⊙. However, we are not able to disentangle different DM scenarios. The computed central mass density of the bulge of ESO 323-G064 resembles the central mass density of some high surface brightness galaxies, rather than that of low surface brightness galaxies. © ESO 2008.
Keywords
galaxies: individual: ESO 323-G064, galaxies: kinematics and dynamics, galaxies: spirals
Publication Title
Astronomy and Astrophysics
Rights
© ESO. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Recommended Citation
VIMOS-VLT integral field kinematics of the giant low surface brightness galaxy ESO 323-G064 L. Coccato, R. A. Swaters, V. C. Rubin, S. D'Odorico and S. S. McGaugh A&A, 490 2 (2008) 589-600 DOI: https://doi.org/10.1051/0004-6361:200810410
Manuscript Version
Final Publisher Version