Search
Now showing items 1-10 of 45
High resolution UVES/VLT spectra of white dwarfs observed for the ESO SN Ia Progenitor Survey III. DA white dwarfs
(2009-10)
Context. The ESO Supernova Ia Progenitor Survey (SPY) took high-resolution spectra of more than 1000 white dwarfs and pre-white dwarfs. About two thirds of the stars observed are hydrogen-dominated DA white dwarfs. Here ...
The B-type giant HD 271791 in the Galactic halo : Linking run-away stars to hyper-velocity stars
(2008-05-01)
Context. Young, massive stars have been found in the distant Galactic halo. Dynamical ejection from the Galactic disc has been suggested as the origin of these "run-away stars". The so-called hyper-velocity stars have been ...
Radial Velocity Variable sdO/Bs from SPY - Preliminary Orbits of Three New Short Period Binaries
(Astronomical Society of the Pacific, 2008)
We present new results from follow-up time-resolved spectroscopy of radial velocity variable hot subdwarfs from the SPY project. Medium resolu- tion spectra were taken at the ESO NTT. Preliminary orbital solutions are ...
Binary sdB Stars with Massive Compact Companions
(Astronomical Society of the Pacific, 2008)
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close ...
Model Spectra of Hot Subdwarfs for the Gaia Mission
(Astronomical Society of the Pacific, 2008)
The Gaia mission will provide an unprecedented 3D view of our galaxy, it will obtain astrometric, photometric and spectrographic data for roughly one billion stars. We are particularly interested in the treasure chest of ...
Metal Abundances of Subdwarf B Stars from SPY - a Pattern Emerges
(Astronomical Society of the Pacific, 2008)
The formation of sdBs is still puzzling, as is the chemical compo- sition of their atmospheres. While helium and other light elements are depleted relative to solar values, heavy elements are highly enriched. Diffusion ...
Hypervelocity Stars: Young and Heavy or Old and Light?
(Astronomical Society of the Pacific, 2008)
The first three hyper-velocity stars (HVS) unbound to the Galaxy were serendipitously discovered in 2005. The only suggested origin of hyper-velocity stars is the Galactic Centre as it hosts a super-massive black hole ...
Binary White Dwarfs in the Supernova Ia Progenitor Survey
(Astronomical Society of the Pacific, 2007)
We report results of a systematic radial velocity survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae: SPY (ESO Supernovae Ia Progenitor surveY). More than 1000 white dwarfs (WDs) and ...
3D-Kinematics of White Dwarfs from the SPY-Project
(Astronomical Society of the Pacific, 2007)
We present a progress report on the kinematical analysis of the entire SPY (ESO SN Ia Progenitor surveY; see Napiwotzki et al. 2001) sample of about one thousand white dwarfs and hot subdwarfs. In a previous study (Pauli ...