EDP Sciences
Free access
Volume 485, Number 2, July II 2008
Page(s) 425 - 433
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20079314
Published online 22 April 2008

A&A 485, 425-433 (2008)
DOI: 10.1051/0004-6361:20079314

Central K-band kinematics and line strength maps of NGC 1399

M. Lyubenova1, H. Kuntschner2, and D. R. Silva3

1  ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
    e-mail: mlyubeno@eso.org
2  Space Telescope European Coordinating Facility, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
    e-mail: hkuntsch@eso.org
3  National Optical Astronomy Observatory, 950 North Cherry Ave., Tucson, AZ, 85748, USA
    e-mail: dsilva@tmt.org

Received 21 December 2007 / Accepted 12 March 2008

In this paper we present for the first time high spatial resolution K-band maps of the central kinematical and near-infrared spectral properties of the giant cD galaxy in the Fornax cluster, NGC 1399. We confirm the presence of a central velocity dispersion dip within $r \le 0\farcs2$ seen in previous long-slit studies. Our velocity dispersion maps give evidence of a non-symmetric structure in this central area by showing three $\sigma$ peaks to the north-east, south-east and west of the galaxy centre. Additionally we measure near-IR line strength indices at unprecedented spatial resolution in NGC 1399. The most important features we observe in our 2-dimensional line strength maps are drops in Na I and CO (2-0) line strength in the nuclear region of the galaxy, coinciding spatially with the drop in $\sigma$. The observed line strength and velocity dispersion changes suggest a scenario where the centre of NGC 1399 harbours a dynamically cold subsystem with a distinct stellar population.

Key words: galaxies: elliptical and lenticular, cD -- galaxies: individual: NGC 1399 -- galaxies: kinematics and dynamics -- galaxies: stellar content -- galaxies: nuclei

© ESO 2008