New distances of unresolved dwarf elliptical galaxies in the vicinity of the Local Group

摘要

We present Surface Brightness Fluctuation distances of nine early- type dwarf galaxies and the S0 galaxy NGC 4150 in the Local Volume based on deep B- and R- band CCD images obtained with the 2.56 m Nordic Optical Telescope. Typically, six stellar fields at various galactocentric distances have been chosen for each galaxy as appropriately free of foreground stars and other contaminants, and Fourier analysed to determine the distances, which are found to lie in the range of 3 to 16Mpc. The SBF method is thus demonstrated to efficiently measure distances from the ground with mid- aperture telescopes for galaxies for which only the tip of the red giant branch method in combination with the Hubble Space Telescope has been available until now. We obtained the following distance moduli: 28.11 +/- 0.15 mag ( or 4.2 +/- 0.3Mpc) for UGC 1703, 27.61 +/- 0.17 mag ( or 3.3 +/- 0.3Mpc) for KDG 61, 29.00 +/- 0.27 mag ( or 6.3 +/- 0.8Mpc) for UGCA 200, 27.74 +/- 0.18 mag ( or 3.5 +/- 0.3Mpc) for UGC 5442, 30.22 +/- 0.17 mag ( or 11.1 +/- 0.9Mpc) for UGC 5944, 30.79 +/- 0.11 mag ( or 14.4 +/- 0.7Mpc) for NGC 4150, 31.02 +/- 0.25 mag ( or 16.0 +/- 1.9Mpc) for BTS 128, 29.27 +/- 0.16 mag ( or 7.1 +/- 0.6Mpc) for UGC 7639, 30.19 +/- 0.23 mag ( or 10.9 +/- 1.2Mpc) for UGC 8799 with an alternative distance of 30.61 +/- 0.26 mag ( or 13.2 +/- 1.7Mpc), and 29.60 +/- 0.20 mag ( or 8.3 +/- 0.8Mpc) for UGC 8882.