Related papers: The Most Precise Extra-Galactic Black-Hole Mass Me…
We describe techniques for measuring the central masses of galaxies using emission-line kinematics observed with the Hubble Space Telescope. For accurate results, it is necessary to model various instrumental effects, particularly the…
We present molecular gas-dynamical mass measurements of the central black holes in the giant elliptical galaxies NGC 4786 and NGC 5193, based on CO(2$-$1) observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and Hubble…
We analyze published reverberation mapping data for three Seyfert galaxies (NGC 3227, NGC 3516, and NGC 4593) to refine the mass estimate for the supermassive black hole in the center of each object. Treatment of the data in a manner more…
We report new precision measurements of the properties of our Galaxy's supermassive black hole. Based on astrometric (1995-2007) and radial velocity (2000-2007) measurements from the W. M. Keck 10-meter telescopes, a fully unconstrained…
We present the spectrum of compact object masses: neutron stars and black holes that originate from single stars in different environments. In particular, we calculate the dependence of maximum black hole mass on metallicity and on some…
Megamaser disks provide the most precise and accurate extragalactic supermassive black hole masses. Here we describe a search for megamasers in nearby galaxies using the Green Bank Telescope (GBT). We focus on galaxies where we believe that…
As a part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotator early-type galaxy NGC 3665. We obtained Combined…
Recent X-ray observations by Jiang et al. have identified an active galactic nucleus (AGN) in the bulgeless spiral galaxy NGC 3319, located just $14.3\pm1.1\,$Mpc away, and suggest the presence of an intermediate-mass black hole (IMBH;…
Using astrometric VLBI observations, we have determined the parallax of the black hole X-ray binary V404 Cyg to be 0.418 +/- 0.024 milliarcseconds, corresponding to a distance of 2.39 +/- 0.14 kpc, significantly lower than the previously…
We present results from a kinematical study of the gas in the nucleus of a sample of three LINER galaxies, obtained from archival HST/STIS long-slit spectra. We found that, while for the elliptical galaxy NGC 5077, the observed velocity…
We present the stellar kinematics in the central 2" of the luminous elliptical galaxy M87 (NGC 4486), using laser adaptive optics to feed the Gemini telescope integral-field spectrograph, NIFS. The velocity dispersion rises to 480 km/s at…
The masses of 68 supermassive black holes (SMBHs) in nearby (z<0.15) active galactic nuclei (AGNs) detected by the INTEGRAL observatory in the hard X-ray energy band (17-60 keV) outside the Galactic plane (|b| > 5 degrees) have been…
Our recent radio observation using the Giant Meter Radio Telescope (GMRT) of the galactic black hole transient A0620-00 at 1.280GHz revealed a micro-flare of a few milli-Jansky. Assuming an equipartition of magnetic energy and the…
Most of the super massive black hole mass estimates based on stellar kinematics use the assumption that galaxies are axisymmetric oblate spheroids or spherical. Here we use fully general triaxial orbit-based models to explore the effect of…
Over a two year period (1995-1997), we have conducted a diffraction-limited imaging study at 2.2 microns of the inner 6"x6" of the Galaxy's central stellar cluster using the Keck 10-m telescope. The K band images obtained reveal a large…
We present upper-limits on the masses of the putative central intermediate-mass black holes in two nearby Galactic globular clusters: 47Tuc (NGC104), the second brightest Galactic globular cluster, and NGC6397, a core-collapse globular…
Accurately determining the black hole mass ($M_\mathrm{BH}$) in active galactic nuclei (AGN) is crucial to constraining their properties and to studying their evolution. While direct methods yield reliable measurements of $M_\mathrm{BH}$ in…
We report the discovery of a strong correlation between the shape of a bulge's light-profile and the mass of its central supermassive black hole (M_{bh}). We find that log(M_{bh}/M_{sun}) = 2.91(+/-0.38)log(n) + 6.37(+/-0.21), where `n' is…
Most galaxies with a well-structured bulge host a supermassive black hole (SMBH) in their centre. Stellar kinematics models applied to adaptive optics (AO) assisted integral field unit observations are well-suited to measure the SMBH mass…
The Event Horizon Telescope (EHT), a global submillimeter wavelength very long baseline interferometry array, unveiled event-horizon-scale images of the supermassive black hole M87* as an asymmetric bright emission ring with a diameter of $…