Related papers: A potential mass-gap black hole in a wide binary w…
Standard stellar evolution models predict that black holes in the range of approximately $50 - 140 M_\odot$ should not exist directly from stellar evolution. This gap appears because stars with masses between 100 and 240 $M_\odot$ are…
We present new X-ray and UV observations of the Wolf-Rayet + black hole binary system NGC 300 X-1 with the Chandra X-ray Observatory and the Hubble Space Telescope Cosmic Origins Spectrograph. When combined with archival X-ray observations,…
Evidence suggests that when compact objects such as black holes and neutron stars form, they may receive a ``natal kick,'' where the stellar remnant gains momentum. Observational evidence for neutron star kicks is substantial, yet limited…
Because of its high mass, the X-ray binary system LMC X-3 is a candidate for a binary system hosting a black hole. The goal of this work is to determine the mass of this black hole and the orbital inclination of the system. Therefore, data…
We pioneer the black hole mass gap as a powerful new tool for constraining modified gravity theories. These theories predict fifth forces that alter the structure and evolution of population-III stars, exacerbating the pair-instability.…
Observations of gravitational waves and their electromagnetic counterparts may soon uncover the existence of coalescing compact binary systems formed by a stellar-mass black hole and a neutron star. These mergers result in a remnant black…
Recently, the red giant V723 Mon is reported to have an unseen companion with a mass of $3.04\pm0.06M_{\odot}$, but question remains about whether it is a single (thus the so-called mass-gap) black hole or an inner binary of two more…
When a compact object is formed, an impulse (kick) will be imparted to the system by the mass lost during the core-collapse supernova (SN). A number of other mechanisms may impart an additional kick on the system, although evidence for…
In black hole X-ray binaries, a misalignment between the spin axis of the black hole and the orbital angular momentum can occur during the supernova explosion that forms the compact object. In this letter we present population synthesis…
Among the compact objects observed in gravitational wave merger events a few have masses in the gap between the most massive neutron stars (NSs) and least massive black holes (BHs) known. Their nature and the formation of their merging…
Stars with an initial mass more than ~25 Msun are thought to ultimately become black holes. Then stellar-mass black holes should be ubiquitous but fewer than 20 have been found in our Galaxy to date, all of which have been found through…
RR Lyrae stars (RRLs) are classical tracers of old stellar populations, yet growing evidence suggests the presence of a metal-rich ([Fe/H]>-0.5), intermediate-age (2-7 Gyr) sub-population in the Milky Way disc. Binary evolution,…
The lack of objects between $2\,M_{\odot}$ and $5\,M_{\odot}$ in the joint mass distribution of compact objects has been termed "mass gap", and attributed mainly to the characteristics of the supernova mechanism precluding their birth.…
The detected Gaia systems hosting compact objects challenge standard models of binary star evolution. In particular, if the observed black hole (BH) systems evolved in isolation, they are expected to have undergone a mass transfer phase.…
Available data on the chirp mass distribution of the coalescing black hole binaries in O1-O3 LIGO/Virgo runs are analyzed and compared statistically with the distribution calculated under the assumption that these black holes are primordial…
In this paper, we study the interaction between the supermassive binary black holes in elliptical orbit and their surrounding disk with a gap. The gap in the disk is a low density region formed due to the tidal effects of the less massive…
Recent intensive observations of the BL Lac object OJ 287 raise a lot of questions on the models of binary black holes, processing jets, rotating helical jets and thermal instability of slim accretion disks. After carefully analyzing their…
Using new and archival radio data, we have measured the proper motion of the black hole X-ray binary V404 Cyg to be 9.2+/-0.3 mas/yr. Combined with the systemic radial velocity from the literature, we derive the full three-dimensional…
We present new constraints on the merging rates of planetary-mass and asteroid-mass primordial black hole binaries using limits on continuous waves(quasi-monochromatic, quasi-infinite duration signals) derived from an all-sky search for…
We have analyzed the observed radial-velocity curve for the X-ray binary M33 X-7 in a Roche model. We have analyzed the dependence between the component masses and the degree of filling of the optical star's Roche lobe to obtain the ratio…