The HYPERMUCHFUSS campaign – An undiscovered high velocity population
Tillich, A Geier, S Heber, U Hirsch, H Maxted, P Gaensicke, B Marsh, T Napiwotzki, R Ostensen, Roy Copperwheat, C
Journal of Physics - Conference Series vol:172 issue:1
16th European White Dwarfs Workshop location:Barcelona date:June 30 - July 4 2008
We present an overview and a status report of HYPERMUCHFUSS (HYPER velocity or Massive Unseen Companions of Hot Faint Underluminious Stars Survey) aiming at the detection of a population of high velocity subluminous B stars and white dwarfs. The first class of targets consists of hot subdwarf binaries with massive compact companions, which are expected to show huge radial velocity variations. The second class is formed by the recently discovered Hyper-velocity stars, which are moving so fast that the dynamical ejection by a supermassive black hole seems to be the only explanation for their origin. Until now only one old HVS has been found, but we expect a larger population. We applied an effecient selection technique for hot subdwarfs and white dwarfs with high galactic restframe velocities from the SDSS spectral data base, which serve as first epoch observations for our campaign with the ESO VLT and NTT in Chile, the 3.5 m telescope at DSAZ observatory (Calar Alto) in Spain and the WHT on La Palma. The survey is nearing completion and provides us with promising candidates which will be followed up to measure their RV-curves to uncover massive companions or prove their nature as HVS.