Related papers: A Three Parsec-Scale Jet-Driven Outflow from Sgr A…

Recent infrared (IR) observations of the center of our Galaxy indicate that the supermassive black hole source Sgr A* is strongly variable in the IR. The timescale for the variability, $\sim 30$ min, is comparable to that of the X-ray…

AGN feedback is now a major component of models of galaxy evolution. Using near-infrared imaging spectroscopy on the VLT we identify kpc-sized outflows of few x 10^10 M_s of ionized gas in powerful radio galaxies at z~2-3. Velocity fields…

An increasing number of observations and simulations suggests that low-power (<10$^{44}$ erg s$^{-1}$) jets may be a significant channel of feedback produced by active galactic nuclei (AGN), but little is known about their actual effect on…

We present radio polarimetric images of 12 Seyfert and Low-Ionization Nuclear Emission-line Region (LINER) galaxies belonging to the Centre for Astrophysics (CfA)+12 micron sample exhibiting kiloparsec-scale radio outflows (KSRs). These…

Our central Galactic supermassive black hole, Sgr A*, exists mostly in a very stable, extremely low-luminosity (~10^{-9} L_Edd), thermal quiescent state, which is interrupted roughly daily by a brief, nonthermal X-ray flare. Because they…

The supermassive black hole at the Galactic center, Sagittarius A*, has experienced periods of higher activity in the past. The reflection of these past outbursts is observed in the molecular material surrounding the black hole but…

We observed Sgr A* and two extragalactic radio sources nearby in angle with the VLBA over a period of two years and measured relative positions with an accuracy approaching 0.1 mas. The apparent proper motion of Sgr A* relative to J1745-283…

In this article we summarise and discuss the infrared, radio, and X-ray emission from the supermassive black hole in the Galactic Centre, SgrA*. We include new results from near-infrared polarimetric imaging observations obtained on May…

The detection of a mm/Sub-mm ``bump'' in Sgr A*'s radio spectrum suggests that at least a portion of its overall emission is produced within a compact accretion torus. This inference is strengthened by observations of strong linear…

We present near-infrared spectra of young radio quasars [P(1.4GHz) ~ 26-27 W/Hz] selected from the Wide-Field Infrared Survey Explorer. The detected objects have typical redshifts of z ~ 1.6-2.5 and bolometric luminosities ~ 10^47 erg/s.…

The Galactic Center is an excellent laboratory for studying phenomena and physical processes that may be occurring in many other galactic nuclei. The Center of our Milky Way is by far the closest galactic nucleus, and observations with…

A large radio outburst from Sgr A* was observed during the VLA weekly monitoring program at 2 cm, 1.3 cm and 7 mm, nearly coincident with the brightest X-ray flare detected to date with the XMM-Newton X-ray Observatory on 2002-10-03. The…

We have performed monitoring observations of the flux density toward the Galactic center compact radio source, Sagittarius A* (Sgr A*), which is a supermassive black hole, from 1996 to 2005 using the Nobeyama Millimeter Array of the…

We present a case study of HE 0040-1105, an unobscured radio-quiet AGN at a high accretion rate (Eddington ratio = 0.19+/-0.04). This particular AGN hosts an ionized gas outflow with the largest spatial offset from its nucleus compared to…

We report the discovery of 11 bipolar outflows within a projected distance of 1pc from Sgr A* based on deep ALMA observations of $^{13}$CO, H30$\alpha$ and SiO (5-4) lines with sub-arcsecond and $\sim1.3$ km/s, resolutions. These…

The radio source Sagittarius A* (Sgr A*), is thought to be a supermassive black hole located at the centre of our Galaxy, that is accreting gas from the surrounding region. Using the high inferred accretion rates, however, standard…

The recent discovery of the G2 cloud of dense, ionized gas on a trajectory toward Sgr A*, the black hole at the dynamical center of the Galaxy, offers a unique opportunity to observe an accretion event onto a massive black hole as well as…

New observations using narrow band imaging, long-slit spectroscopy and MERLIN observations of the nuclear region of the Seyfert galaxy NGC~4051 have been made. An edge brightened, triangular region of ionized gas extending 420 pc from the…

The fluorescent X-ray emission from neutral iron in the molecular clouds (Sgr B) indicates that the clouds are being irradiated by an external X-ray source. The source is probably associated with the Galactic central black hole (Sgr A*),…

Sagittarius A* (Sgr A*), the Galactic Center supermassive black hole (SMBH), is one of the best targets to resolve the innermost region of SMBH with very long baseline interferometry (VLBI). In this study, we have carried out observations…