Related papers: Unveiling black holes ejected from globular cluste…
We report the detection of a black hole (NGC 1850 BH1) in the $\sim$100 Myr-old massive cluster NGC~1850 in the Large Magellanic Cloud. It is in a binary system with a main-sequence turn-off star (4.9 $\pm$ 0.4 M${_\odot}$), which is…
The first gamma-ray line originating from outside the solar system that was ever detected is the 511 keV emission from positron annihilation in the Galaxy. Despite 30 years of intense theoretical and observational investigation, the main…
The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black…
We present results from an extensive study of 88 precessing, equal-mass black-hole binaries with large spins (83 with intrinsic spins of 0.8 and 5 with intrinsic spins of 0.9)and use these data to model new nonlinear contributions to the…
The existence of intermediate-mass black holes (IMBHs) is crucial for understanding various astrophysical phenomena, yet their existence remains elusive, except for the LIGO-Virgo detection. We report the discovery of a high-velocity star…
Recent observations have found a 1700 km/s star [S5-HVS1] that was ejected from the Galactic Center approximately five million years ago. This star was likely produced by tidal disruption of a binary. In particular, the Galactic Center…
An error was detected in the code of one of the components considered to model the optical/UV emission of the Galactic ULX pulsar Swift J0243.6+6124 during its 2017 giant outburst. This led to an overestimation of the contribution from the…
According to recent general-relativistic simulations, the coalescence of two spinning black holes (BHs) could lead to recoil speeds of the BH remnant of up to thousands of km/s as a result of the emission of gravitational radiation. Such…
We present observations of highly inclined, HI deficient, Virgo cluster spiral galaxies. Our high-resolution VLA HI observations of edge-on galaxies allow us to distinguish extraplanar gas from disk gas. All of our galaxies have truncated…
We report on fast (msec) simultaneous observations in X-rays and optical light of the black hole candidate XTE J1118+480, showing correlation on time scales from 20msec to several seconds. The shape of the correlation is not easily…
Until recently it was thought that high Galactic latitude clouds were a non-star-forming ensemble. However, in a previous study we reported the discovery of two embedded clusters (ECs) far away from the Galactic plane ($\sim5$ kpc). In our…
This article has been withdrawn by arXiv admins due to excessive reuse of content from other authors. We also note that this article has been retracted from Physics Letters B at http://doi.org/10.1016/j.physletb.2015.03.024
We present a deep Chandra observation of the extremely massive spiral galaxy 2MASX J23453268-0449256, the first X-ray observation of this very rare system which features the largest known relativistic jets from a spiral galaxy. We detect…
We present an X-ray/UV/optical spectrum of the black hole primary in the X-ray nova XTE J1118+480 in quiescence at L_x = 4 x 10^{-9} of the Eddington luminosity. The Chandra, HST and MMT spectroscopic observations were performed…
Magain et al. (2005) argued that the host galaxy of the quasar in HE0450-2958 is substantially under-luminous given the likely mass of its nuclear black hole. Using kinematical information from the spectra of the quasar and the companion…
There is some weak evidence that the black hole merger named GW190521 had a non-zero eccentricity. In addition, the component black holes' masses exceeded the limit predicted by stellar evolution. The large masses can be explained by…
The observed galactic 511 keV line has been interpreted in a number of papers as a possible signal of dark matter annihilation within the galactic bulge. If this is the case then we should expect a similar spectral feature associated with…
We have obtained optical and infrared photometry of the quiescent soft X-ray transient XTE J1118+480. In addition to optical and J-band variations, we present the first observed H- and K_s-band ellipsoidal variations for this system. We…
Gravitational torques among objects orbiting a supermassive black hole drive the rapid reorientation of orbital planes in nuclear star clusters (NSCs), a process known as vector resonant relaxation. In this Letter, we determine the…
We present a detailed X-ray and optical study of a distant fossil system RX J1416.4+2315 (z=0.13), combining Chandra and XMM-Newton observations, optical photometry and spectroscopy. X-ray emitting hot gas imaged by both the Chandra and…