A Survey for Low Surface Brightness Dwarf Galaxies Around M31

Abstract

By applying a digital filtering technique to 1550 square degrees of the POSS-II in the vicinity of M31, we found two previously unidentified very low surface brightness dwarf galaxies which we designate And V and VI. Follow-up imaging with the KPNO 4-m telescope resolved these into stars easily. The V- and I- band images of And V indicate a distance similar to that of M31, and <[Fe/H]> approximately -1.5. All evidence strongly supports its classification as a dwarf spheroidal companion to M31. Data for And VI are being analyzed, but preliminary indications support a similar conclusion. Our search for more dwarfs, including follow-up observations of numerous candidates found via digital filtering, is incomplete; thus, further identifications may be forthcoming.

To be published in "The Low Surface Brightness Universe", Proceedings of IAU Colloquium 171, edited by J. I. Davies, C. Impey, and S. Phillipps; 1 embedded PostScript figure, 3 JPEG figures; see http://aloe.tuc.noao.edu/jacoby/dwarfs.html for a complete embedded PostScript version