Redshift-Distance Survey of Early-Type Galaxies: Circular-Aperture Photometry

• Published in: The Astronomical journal 2003-05, Vol.125 (5), p.2307-2324
• Main Authors: Alonso, M. V, Bernardi, M, da Costa, L. N, Wegner, G, Willmer, C. N. A, Pellegrini, P. S, Maia, M. A. G
• Format: Article
• Language: English
• Subjects: Astrophysics; Cosmology and Extra-Galactic Astrophysics; Physics
• ISSN: 1538-3881; 0004-6256; 1538-3881
• DOI: 10.1086/374766

We present R-band CCD photometry for 1332 early-type galaxies, observed as part of the ENEAR survey of peculiar motions using early-type galaxies in the nearby Universe. Circular apertures are used to trace the surface brightness profiles, which are then fit by a two-component bulge-disk model. From the fits we obtain the structural parameters required to estimate galaxy distances using the D_n-sigma and Fundamental Plane relations. We find that about 12% of the galaxies are well represented by a pure r^{1/4} law while 87% are best fit by a two component model. There are 356 repeated observations of 257 galaxies obtained during different runs that are used to derive statistical corrections and bring the data to a common system. We also use these repeated observations to estimate our internal errors. The accuracy of our measurements are tested by the comparison of 354 galaxies in common with other authors. Typical errors in our measurements are 0.011 dex for log{D_n}, 0.064 dex for log{r_e}, 0.086 mag arcsec^{-2} for and 0.09 for m_{R_C}, comparable to those estimated by other authors. The photometric data reported here represent one of the largest high-quality and uniform all-sky samples currently available for early-type galaxies in the nearby universe, especially suitable for peculiar motion studies.