Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC4258

  title={Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC4258},
  author={Makoto Miyoshi and James Moran and James Rezso Herrnstein and Lincoln J. Greenhill and Naomasa Nakai and Philip J. Diamond and Makoto Inoue},
MANY galaxies are thought to contain massive black holes— exceeding ten million solar masses—at their centres1,2, but firm observational evidence has proved to be surprisingly elusive. The best evidence comes from observing gas or stars rotating rapidly within a small region around a central body. If the observed velocities are due solely to the gravitational force of the central body—as in the Solar System-then the mass of the central body can be readily calculated. Here we present… 
A massive black hole at the centre of the quiescent galaxy M32
Massive black holes are thought to reside at the centres of many galaxies1,2, where they power quasars and active galactic nuclei. But most galaxies are quiescent, indicating that any central massive
Observational evidence for massive black holes in the centers of active galaxies
Naturally occurring water vapor maser emission at 1.35 cm wavelength provides an accurate probe for the study of accretion disks around highly compact objects, thought to be black holes, in the
Observations of stellar proper motions near the Galactic Centre
EVIDENCE for a massive black hole at the centre of our Galaxy has been accumulating for the past two decades 1−7. Estimates of the mass of this region have hitherto been based on the spectroscopic
The massive black hole at the galactic center
At the dynamic center of the Milky Way high spatial resolution, near-infrared imaging and spectroscopy have made it possible in the last few years to measure stellar velocities down to separations of
A Stringent Constraint on Alternatives to a Massive Black Hole at the Center of NGC 4258
There is now dynamical evidence for massive dark objects at the center of several galaxies, but suggestions that these are supermassive black holes are based only on indirect astrophysical arguments.
HST Detections of Massive Black Holes in the Centers of Galaxies
After correcting spherical aberration in the Hubble Space Telescope in 1993, the central masses of galaxies can be measured with a resolution 5 to 10 times better than can be achieved at the best
Observational Evidence for Black Holes
Astronomers have discovered two populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, millions of which are present in each galaxy in the universe,
Evidence for a Massive Black Hole in the S0 Galaxy NGC 4342
We present axisymmetric dynamical models of the edge-on S0 galaxy NGC 4342. This small low-luminosity galaxy harbors, in addition to its outer disk, a bright nuclear stellar disk. A combination of
Recent progress in the search for black holes in galactic nuclei
Massive nuclear black holes of 10^6 - 10^9 solar masses are believed to be responsible for the the energy production in quasars and active galaxies, and are thought to be present in many quiescent
Toward Precision Black Hole Masses with ALMA: NGC 1332 as a Case Study in Molecular Disk Dynamics
We present first results from a program of Atacama Large Millimeter/submillimeter Array (ALMA) CO(2-1) observations of circumnuclear gas disks in early-type galaxies. The program was designed with


Extremely-high-velocity H20 maser emission in the galaxy NGC4258
WATER-VAPOUR maser emission at 22.23508 GHz has been observed in star-forming regions of our own galaxy and in the active nuclei of other galaxies1–5. Maser emission from active galactic nuclei is
HST FOS spectroscopy of M87: Evidence for a disk of ionized gas around a massive black hole
Using the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) to observe the central region of M87, we have obtained spectra covering approximately 4600-6800 A at a spectral
Narrowband HST images of M87: Evidence for a disk of ionized gas around a massive black hole
We present Hubble Space Telescope Wide Field/Planetary Camera-2 (HST WFPC2) narrowband H-alpha + (N II) images of M87 which show a small disk of ionized gas with apparent spiral structure surrounding
Compact OH megamaser and probable quasar activity in the galaxy Arp 220
ARP 220 is the prototype far-infrared ultraluminous galaxy, and the origin of its luminosity—a burst of massive star formation or a quasar obscured by a layer of dense gas and dust—has been the
Evidence for a Supermassive Black Hole in NGC 3115
Stellar rotation velocities and velocity dispersions along the major and minor axes of the edge-on S0 galaxy NGC 3115 have been measured in effective seeing σ * =0″.42-0″.69 with the
Water maser emission from X-ray-heated circumnuclear gas in active galaxies
We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas
Theory of extragalactic radio sources
Powerful extragalactic radio sources comprise two extended regions containing magnetic field and synchrotron-emitting relativistic electrons, each linked by a jet to a central compact radio source
Water-vapour maser emission from galactic nuclei
We report here the progress of a survey of galactic nuclei for water-vapour maser emission at 22.235 GHz. We observed 29 late-type galaxies in November 1982, January 1983, and September 1983 using
VLBI observations of the water vapor maser in the nucleus of NGC 3079
The water vapor maser source in the nucleus of NGC 3079 has been observed with a four-station intercontinental VLBI array, which had a resolution of 0.3 mas. VLA observations of NGC 3079 show that
The braided jets in the spiral galaxy NGC 4258
The Hawaii Imaging Fabry-Perot Interferometer have been used to synthesize 44000 Hα and [N II] emission-line profiles at velocity resolution 68 km/s FWHM across the disk of the nearby Seyfert/LINER