Low signal-to-noise spectroscopy and surface photometry of two faint galaxies in the field of NGC 7479

¹ Departamento de Astronomia, Instituto de Física, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, 91501-970  Porto Alegre, RS, Brasil
² Department of Astronomy and McDonald Observatory, University of Texas at Austin, Austin, Texas 78712-1083, USA e-mail: fritz@astro.as.utexas.edu

Corresponding author: M. F. Saraiva, fatima@if.ufrgs.br

Received: 16 April 2003
Accepted: 29 July 2003

Abstract

We present low signal-to-noise spectroscopy and surface photometry of two small galaxies, detected in the field of the nearby asymmetric barred spiral NGC 7479, near a prolongation of the western arm that forms a faint tail in the disc, and selected as possible companions of this galaxy. The analysis was based on data obtained with the Prime Focus Camera (PFC) at the 0.8 m telescope of McDonald Observatory, and the Low Resolution Spectroscope (LRS) at the 9.2 m Hobby-Eberly Telescope (HET). We determined radial velocities using cross correlation with 15 different templates, and derived integrated magnitudes, colors and brightness profiles for each. 
The derived radial velocities are around 35 500 for one galaxy and 38 000 for the other, which clearly indicates that both are far more distant than the nearby NGC 7479. The absolute magnitudes and diameters of these two background galaxies are typical of normal galaxies, and their colors are similar to other galaxies with similar redshifs. NGC 7479 continues to exist in isolation with no detected companion.