Surface photometry of radio loud elliptical galaxies from the B2 sample

Send offprint request: J.I. González-Serrano,
e-mail: gserrano@ifca.unican.es

1 - Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, Facultad de Ciencias, E-39005 Santander, Spain
2 - Departamento de Física Moderna, Universidad de Cantabria, Facultad de Ciencias, E-39005 Santander, Spain

Abstract:

V-band CCD imaging is presented for 72 galaxies from the B2 radio sample (Colla et al. [1975]; Fanti et al. [1978]), with redshifts up to 0.2 and radio powers P₄₀₈=10²³-10^26.5 W Hz^-1. According to the morphology on the optical images 57 galaxies are classified as ellipticals, 6 as spirals and 7 as irregular. Surface photometry of the sample of ellipticals was obtained fitting ellipses to the light distribution. The light profile of these galaxies generally follows a de Vaucouleurs law, although in three cases the profiles show large excesses relative to the r^1/4 law at large radii. The fitted $\mu_{\rm e}$ and $r_{\rm e}$ parameters for the de Vaucouleurs galaxies are given in the paper. Three of the ellipticals show a bright nucleus. One of them is a known broad line radio galaxy (B2 1833+32) and the remaining two are Markarian galaxies, classified in the literature as BL Lac objects (B2 1101+38 and B2 1652+39). The radial profiles for ellipticity, position angle, and B₄ term of the Fourier analysis are presented in the paper, and the morphological peculiarities of the ellipticals are described, including the presence of shells, tails, nuclear dust, isophote twisting, off-centering, and boxiness or diskness of the isophotes. Only one of the galaxies in this work is included in the subsample of B2 radio galaxies with well-defined jets (Parma et al. [1987]). In this sense the present sample complements the sample of 24 radio galaxies with well-defined radio jets in Parma et al. for which a similar study was presented in González-Serrano et al. ([1993]).

The irregular galaxy B2 0916+33 appears to be misclassified, and we suggest that the right identification of the radio source is a nearby point like object with V=18.45 mag. The spiral galaxy associated with B2 1441+26 is also misclassified. A point-like optical object with V=18.88 mag, located at $\sim 36$ arcsec from the original identification and coincident with the radio core is the most probable counterpart.

Key words: galaxies: active -- galaxies: fundamental parameters -- galaxies: photometry -- radio continuum: galaxies