B and R Surface Photometry of Faint Galaxies in the Area of Three Cosmic Voids

Extract

We performed B and R surface photometry of 92 faint mostly late type galaxies, selected towards three nearby voids (Hopp et al., 1995 A&AS 109, 537). CCD frames were taken with the Calar Alto 3.5m telescope and with the MPIA/ESO 2.2m telescope. We calculated the azimuthally averaged equivalent profiles, asymtotic total magnitudes and colours, and performed ellipse-fitting of isophotes. Observed light profiles were fitted with a power law μ = μ₀ + 1.086αr ^1/n . About 40% of profiles are pure exponentials (n = 1); 38% of the profiles reveal a bulge/disk or disk/disk composition; 20% of them show central light depression. We classified the nearby galaxies (z ≤ 0.04) as being related either to clusters (11 galaxies), to sheets (23) or to voids (9). The obtained parameters are compared to those of HSB and of LSB field galaxies.