Dwarf Galaxies in the Nearby Lynx-Cancer Void: Photometry, Colours and Ages

摘要

The nearby Lynx-Cancer void is a good laboratory to study the effect of very rarefied environment on the evolution of the least massive dwarf galaxies. A recently compiled sample of this void's galaxies includes about one hundred objects with M_B in the range - 12 to - 18 mag. Good quality images are available in the SDSS database for ～80% of the sample. Their u, g, r,i,z photometry allows one to derive galaxy stellar mass (and, incorporating HI data, gas mass-fraction) and ages of visible stellar populations, and hence, the epoch of their formation (first SF episode). We present the first photometric results of the ongoing study of the Lynx-Cancer void.