相关论文: The first accurate parallax distance to a black ho…
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 report a direct and accurate measurement of the distance to the X-ray binary Cygnus X-1, which contains the first black hole to be discovered. The distance of 1.86 (-0.11,+0.12) kpc was obtained from a trigonometric parallax measurement…
Using the Very Long Baseline Array and the European Very Long Baseline Interferometry Network we have made a precise measurement of the radio parallax of the black hole X-ray binary MAXI\,J1820+070, providing a model-independent distance to…
Using the Very Long Baseline Array, we have measured a trigonometric parallax for the micro quasar GRS 1915+105, which contains a black hole and a K-giant companion. This yields a direct distance estimate of 8.6 (+2.0,-1.6) kpc and a…
We investigated the reported distances of Galactic black hole (BH) and neutron star low-mass X-ray binaries (LMXBs). Comparing the distances derived for the neutron stars CygX-2 and XTE J2123-058 using the observed Eddington limited…
We have used the Hubble Space Telescope to measure the motion in the sky and compute the galactocentric orbit of the black hole X-ray binary GRO J1655-40. The system moves with a runaway space velocity of $112\pm 18$ km s$^{-1}$ in a highly…
The quadruple lensed system WGD2038-4008 was recently discovered with the help of new techniques and observations. Even though black hole mass has been estimated for lensed quasars, it has been calculated mostly for one broad emission line…
We present analysis of comprehensive radio observations of the black hole V404 Cyg during its 2015 outburst. These data represent the best ever coverage of jet production and particle acceleration from any black hole. We report for the…
The active galaxy NGC 4151 has a crucial role as one of only two active galactic nuclei for which black hole mass measurements based on emission line reverberation mapping can be calibrated against other dynamical methods. Unfortunately,…
Observations of V404 Cyg performed with the Westerbork Synthesis Radio Telescope at four frequencies, over the interval 1.4-8.4 GHz, have provided us with the first broadband radio spectrum of a `quiescent' stellar mass black hole. The…
We examine the distribution of masses of black holes in transient low mass X-ray binary systems. A Bayesian analysis suggests that it is probable that six of the seven systems with measured mass functions have black hole masses clustered…
We report on a first census of Galactic black hole X-ray binary (BHXRB) properties with the second data release (DR2) of {\em Gaia}, focusing on dynamically confirmed and strong candidate black hole transients. DR2 provides five-parameter…
We calculate the time delay between different relativistic images formed by black hole gravitational lensing in the strong field limit. For spherically symmetric black holes, it turns out that the time delay between the first two images is…
We report results of Chandra X-ray and VLA radio observations of the Galactic accreting black hole V404 Cyg (GS 2023+338) in its quiescent state. V404 Cyg is detected at its faintest level of radio and X-ray emission with a 0.5-10 keV…
We model the dynamical structure of M87 (NGC4486) using high spatial resolution long-slit observations of stellar light in the central regions, two-dimensional stellar light kinematics out to half of the effective radius, and globular…
As one of the best-characterized stellar-mass black holes, with good measurements of its mass, distance and inclination, V404 Cyg is the ideal candidate to study Eddington-limited accretion episodes. After a long quiescent period, V404 Cyg…
We present the results of a recent reverberation mapping campaign for UGC 06728, a nearby low-luminosity Seyfert 1 in a late-type galaxy. Nightly monitoring in the spring of 2015 allowed us to determine an H$\beta$ time delay of $\tau = 1.4…
We show that the black hole in the x-ray binary Cygnus X-1 was formed in situ and did not receive an energetic trigger from a nearby supernova. The progenitor of the black hole had an initial mass greater than 40 solar masses and during the…
We test two different methods of using near-infrared extinction to estimate distances to dark clouds in the first quadrant of the Galaxy using large near infrared (2MASS and UKIDSS) surveys. VLBI parallax measurements of masers around…
Stellar-mass black holes ($3$ $M_\odot \lesssim M_{\rm BH} \lesssim 150$ $M_\odot$) are the natural product of the evolution of heavy stars ($M_{\rm star} \gtrsim 20$ $M_\odot$). In our Galaxy, we expect $10^8$-$10^9$ stellar-mass black…