83 citations · 580 across the 11 of their papers we have counts for
6 papers · 1 filter
A spectroscopic and kinematic survey of fast hot subdwarfs
S. Geier, U. Heber, A. Irrgang +19
Hot subdwarfs (sdO/B) are the stripped helium cores of red giants formed by binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed…
Runaway blue main-sequence stars at high Galactic latitudes. Target selection with Gaia and spectroscopic identification
Roberto Raddi, Andreas Irrgang, Ulrich Heber +2
Motivated by the historical identification of runaway main-sequence (MS) stars of early spectral type at high Galactic latitudes, we test the capability of Gaia at identifying new…
A stripped helium star in the potential black hole binary LB-1
Andreas Irrgang, Stephan Geier, Simon Kreuzer +2
The recently claimed discovery of a massive () black hole in the Galactic solar neighborhood has led to controversial discussions because it…
The EREBOS project -- Investigating the effect of substellar and low-mass stellar companions on late stellar evolution
V. Schaffenroth, B. N. Barlow, S. Geier +14
Eclipsing post-common envelope binaries are highly important for resolving the poorly understood, very short-lived common envelope phase. Most hot subdwarfs (sdO/Bs) are the bare H…
Hypervelocity stars in the Gaia era: Runaway B stars beyond the velocity limit of classical ejection mechanisms
Andreas Irrgang, Simon Kreuzer, Ulrich Heber
Young massive stars in the halo are assumed to be runaway stars from the Galactic disk. Possible ejection scenarios are binary supernova ejections (BSE) or dynamical ejections from…
A quantitative spectral analysis of 14 hypervelocity stars from the MMT survey
Andreas Irrgang, Simon Kreuzer, Ulrich Heber +1
Hypervelocity stars (HVSs) travel so fast that they may leave the Galaxy. The tidal disruption of a binary system by the supermassive black hole in the Galactic center is widely as…