Related papers: Wolf-Rayet -- compact object binaries as progenito…
BH-NS and BH-BH systems are among the most promising gravitational wave sources detectable by advanced LIGO/VIRGO and the Einstein Telescope. Although the rates of these systems may be above those of NS-NS mergers, BH-NS and BH-BH systems…
We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact binary stars are expected to be the most important sources for the forthcoming…
Wolf-Rayet stars (WRs) are one of the final evolutionary stages of massive stars and immediate progenitors of stellar-mass black holes. Their multiplicity forms an important anchor point in single and binary population models for predicting…
The WN3/O3 Wolf-Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the absorption lines of a hot O-type star, but our prior work has…
The observed late-type WC Wolf-Rayet stars (WC7-9) with low luminosity below $\rm \log L/L_{\odot} < 5.4$ in the HR diagram cannot be reproduced satisfactorily by the evolutionary track of single stars. The mass transfer due to Roche lobe…
Six gravitational wave events have been reported by the LIGO-Virgo collaboration (LVC), five of them associated with black hole binary (BHB) mergers and one with a double neutron star (DNS) merger, while the coalescence of a black…
The development of advanced gravitational wave (GW) observatories, such as Advanced LIGO and Advanced Virgo, provides impetus to refine theoretical predictions for what these instruments might detect. In particular, with the range…
The recently discovered burst of gravitational waves GW150914 provides a good new chance to verify the current view on the evolution of close binary stars. Modern population synthesis codes help to study this evolution from two main…
We perform a systematic study of merging black hole (BH) binaries with compact star (CS) companions, including black hole--white dwarf (BH--WD), black hole--neutron star (BH--NS) and black hole--black hole (BH--BH) systems. Previous studies…
We explore the implications of the observed low spins aligned with the orbital axis in Advanced~LIGO~O1 run on binary black hole (BBH)~merger scenarios in which the merging BBHs have evolved from field binaries. The coalescence time…
The first directly detected gravitational waves (GW 150914) were emitted by two coalescing black holes (BHs) with masses of ~36Msun and ~29Msun. Several scenarios have been proposed to put this detection into an astrophysical context. The…
Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects with huge mass-loss, they are likely the last…
The unprecedented range of second-generation gravitational-wave (GW) observatories calls for refining the predictions of potential sources and detection rates. The coalescence of double compact objects (DCOs)---i.e., neutron star-neutron…
We show that the recently discovered binary 2M05215658+4359220 (2M0521), comprised of a giant star (GS) orbiting a suspected black hole (BH) in a ~80 day orbit, may be instrumental in shedding light on uncertain BH-formation physics and can…
We show that black-hole High-Mass X-ray Binaries (HMXBs) with O- or B-type donor stars and relatively short orbital periods, of order one week to several months may survive spiral in, to then form Wolf-Rayet (WR) X-ray binaries with orbital…
Gaia has recently revealed a population of over 20 compact objects in wide astrometric binaries, while LIGO-Virgo-KAGRA (LVK) have observed around 100 compact object binaries as gravitational-wave (GW) mergers. Despite belonging to…
Context. Long-period Wolf-Rayet (WR) star binaries produced by mass transfer are predicted to be abundant, but are observationally rare. This yields constraints on the evolution of initially wide O star binaries, including those potentially…
The majority of core-collapse supernova (CCSN) progenitors are massive stars in multiple systems, and their evolution and final fate are affected by interactions with their companions. These interactions can explain the presence of…
WR 20a is the most massive close-in binary known in our Galaxy. It is composed of two $\approx$80 M$_\odot$ Wolf-Rayet stars with a short period of $\approx$3.7 days in the open cluster Westerlund 2. As such, WR 20a presents us with a…
Recent discoveries of gravitational wave (GW) events most likely originating from black hole (BH) + neutron star (NS) mergers reveal the existence of BH+NS binaries. The formation of BH+NS binaries and their merger rates through isolated…