EDP Sciences
Free access
Issue
A&A
Volume 391, Number 2, August IV 2002
Page(s) 531 - 545
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20020904


A&A 391, 531-545 (2002)
DOI: 10.1051/0004-6361:20020904

Near-infrared surface photometry of early-type galaxies

S. B. Rembold1, M. G. Pastoriza1, J. R. Ducati1, M. Rubio2 and M. Roth3

1  Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, 91501-970 Porto Alegre, Brazil
    e-mail: rembold@if.ufrgs.br;mgp@if.ufrgs.br;ducati@if.ufrgs.br
2  Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
    e-mail: mrubio@das.uchile.cl
3  Carnegie Institution of Washington, Las Campanas Observatory, Casilla 601, La Serena, Chile
    e-mail: mroth@lco.cl

(Received 24 April 2002 / Accepted 23 May 2002)

Abstract
CCD infrared ( $JHK_{\rm s}$) photometry was performed on a sample of 10 elliptical and 2 lenticular galaxies. Isophotal parameters, brightness profiles, integrated colors and color gradients are presented. Color gradients found are very weak, showing bluer colors towards the outer regions. The colors of the sample galaxies are compatible with stellar populations like those found in metal-rich clusters of the Galaxy; objects NGC $\,$7192, NGC $\,$7562 and NGC $\,$7619 are compatible with less metal-rich populations. The brightness profile of most galaxies is well described by the r1/4 law. The profiles of NGC 1600 and NGC 720 are described by Sérsic's law with $n\sim{1.5}$ and $n\sim{1.8}$ respectively. The infrared effective radius of the objects studied is typically one half of its counterpart in the B band, which can be an indication that the stellar population that dominates the infrared emission is more concentrated in the central regions. We show that the sample satisfies the Fundamental Plane relation of elliptical galaxies in the infrared, with an rms scatter of 0.20 for J and H and 0.23 for $K_{\rm s}$.


Key words: galaxies: elliptical and lenticular, cD -- galaxies: stellar content -- galaxies: photometry

Offprint request: S. B. Rembold, rembold@if.ufrgs.br




© ESO 2002