SIMBAD references

It has been suggested that some high-velocity hydrogen clouds, rather than being associated with the Galaxy, may be dispersed throughout the Local Group. If true these hydrogen clouds may be the `debris' left over from the formation of the Local Group predicted by numerical simulations. Some of these clouds have measured HI column densities higher than that normally assumed to be the threshold for star formation, and they are metal-enriched. We have carried out V - and I -band CCD observations of three compact high-velocity hydrogen clouds from the sample of Braun & Burton in an attempt to detect resolved giant branch tip stars and/or diffuse emission. We detect no stars that can be associated with the hydrogen clouds down to a magnitude limit of m_V= 23.3 and m_I= 22.0. We find no diffuse emission down to a central surface brightness limit of ~25.0 µ_V.