Related papers: Hydrodynamical Accretion Onto Sgr A* From Distribu…
We present a statistical analysis of polarized near-infrared (NIR) light from Sgr A*, the radio source associated with the supermassive black hole at the center of the Milky Way. The observations have been carried out using the adaptive…
Approximately once every $10^4$ years, a star passes close enough to the supermassive black hole Sgr A* at the center of the Milky Way to be pulled apart by the black hole's tidal forces. The star is then "spaghettified" into a long stream…
The formation of massive black holes and their coevolution with host galaxies are pivotal areas of modern astrophysics. Spherical accretion onto a central point mass serves as a foundational framework in cosmological simulations,…
The scattering diameters of Sgr A* and several nearby OH masers (~ 1" at 1 GHz) indicate that a region of enhanced scattering is along the line of sight to the Galactic center. The scattering diameter of an extragalactic source seen through…
We develop an analytic, steady-state model for the gas environment in quiescent galactic nuclei. We assume that the mass is constantly supplied by a spherically symmetric distribution of wind emitting stars, and that gravity is solely due…
A pair of giant gamma-ray bubbles have been revealed by the {\it Fermi} LAT. In this paper we investigate their formation mechanism. Observations have indicated that the activity of the supermassive black hole located at the Galactic…
The hypothesized supermassive black hole in the nucleus of M31 (which we shall hereafter call M31*) has many features in common with Sgr A* at the Galactic Center, yet they differ in several significant and important ways. Though M31* is…
We show that the recently-discovered orbits of massive stars with closest approach of ~10^3 Schwarzschild radii from SgrA*, allow winds from these stars to provide the required mass deposition rate near the black hole horizon. The observed…
The vicinity of the supermassive black hole associated with the compact radio source Sagittarius (Sgr) A* is believed to dominate the observed emission at wavelengths near and shorter than $\sim$ 1 millimeter. We show that a general…
Gaia BH3 is the most massive known stellar-origin black hole in the Milky Way, with a mass $M_\bullet \approx 33 \, \rm M_\odot$. Detected from Gaia's astrometry, this black hole is in the mass range of those observed via gravitational…
Sub milli-arcsecond astrometry and imaging of the black hole Sgr A* at the Galactic centre may become possible in the near future at infrared and sub-millimetre wavelengths. Motivated by observations of short-term infrared and X-ray…
Several processes may limit the accretion rate onto a super-massive black hole (SMBH). Two processes that are commonly considered (e.g., for sub-grid prescriptions) are Bondi-Hoyle-Lyttleton accretion and the Eddington limit. A third one is…
We revisit theoretical and observational constraints on geometrically-thin disk accretion in Sagittarius A* (Sgr A*). We show that the combined effects of mass outflows and electron energization in the hot part of the accretion flow can…
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…
PAPER WITHDRAWN. The recent detection of Sgr A* in the X-ray band, together with the radio polarization measurements conducted over the past few years, offer the best constraints yet for understanding the nature of the emitting gas within…
LS 5039 is a TeV gamma-ray binary with extended radio emission. It consists of a compact object in the mildly eccentric (e=0.35), 3.9-day orbit around a massive O star. The nature of the compact object is not yet established. In this paper,…
The extremely hot and tenuous accretion flow in the immediate vicinity of Sgr A* is believed to be invisible (too dim) in the X-ray band, except for short X-ray flares. Here we point out that during pericenter passages, close brightest…
The inner few parsecs at the Galactic Center have come under intense scrutiny in recent years, in part due to the exciting broad-band observations of this region, but also because of the growing interest from theorists motivated to study…
Sgr A* is the unique 1 Jy flat spectrum radio point source located at the dynamical center of the Galaxy and in the very center of the central star cluster. Due to its unusual appearance it has long been speculated that this source is…
Recent high resolution observations of the Galactic center black hole allow for direct comparison with accretion disk simulations. We compare two-temperature synchrotron emission models from three dimensional, general relativistic…