Related papers: 7 mm lambda VLBA Observations of Sagittarius A*

In the centre of our galaxy lies a super-massive black hole, identified with the radio source Sagittarius A*. This black hole has an estimated mass of around 4 million solar masses. Although Sagittarius A* is quite dim in terms of total…

We study the environment of Sgr A* using spectral and continuum observations with the ALMA and VLA. Our analysis of sub-arcsecond H30alpha, H39alpha, H52alpha and H56alpha line emission towards Sgr A* confirm the recently published broad…

We present a large-scale, interferometric survey of ammonia (1,1) and (2,2) toward the Galactic Center observed with the Australia Telescope Compact Array (ATCA). The survey covers Delta l ~1degree (~150pc) at an assumed distance of 8.5…

The linearly polarized millimeter and sub-millimeter emission in Sagittarius A* is produced within 10 Schwarzschild radii of the supermassive black hole at the Galactic Center and may originate from a hot magnetized accretion disk, where…

The absolute position of Sgr A*, the compact radio source at the center of the Milky Way, had been uncertain by several tens of milliarcseconds. Here we report improved astrometric measurements of the absolute position and proper motion of…

We report the first time-series of broadband infrared (IR) color measurements of Sgr A*, the variable emission source associated with the supermassive black hole at the Galactic Center. Using the laser and natural guide star AO systems on…

We present high-resolution multiwavelength radio continuum images of the region within 150$"$ of Sgr A*, revealing a number of new extended features and stellar sources in this region. First, we detect a continuous 2" east-west ridge of…

Based on our deep image of Sgr A using broadband data observed with the Jansky VLA at 6 cm, we present a new perspective of the radio bright zone at the Galactic center. We further show the radio detection of the X-ray Cannonball, a…

High-resolution, multi-wavelength, and time-domain observations of the Galactic centre black hole candidate, Sgr A*, allow for a direct test of contemporary accretion theory. To date, all models have assumed alignment between the accretion…

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…

We analyze the gas and dust emission in the immediate vicinity of the supermassive black hole Sgr~A* at the Galactic center (GC) with the ESO VLT (Paranal/Chile) instruments SINFONI and VISIR. The SINFONI H+K data cubes show several…

A radio source at the Galactic center Sgr A* is a prime supermassive black hole candidate and therefore key to developing our understanding of them. Time variations in the 230 GHz band flux of Sgr A* have been found with the Atacama Large…

We summarize three recent publications which suggest that the Galactic center region Sagittarius B (Sgr B) may contain non-thermal radio components (Crocker et al. 2007, Hollis et al. 2007 and Yusef-Zadeh et al. 2007a). Based on new VLA…

We summarize basic observational results on Sagittarius~A* obtained from the radio, infrared and X-ray domain. Infrared observations have revealed that a dusty S-cluster object (DSO/G2) passes by SgrA*, the central super-massive black hole…

We present the result of 6 years monitoring of SgrA*, radio source associated to the supermassive black hole at the centre of the Milky Way. Single dish observations were performed with the Itapetinga radio telescope at 7 mm, and the…

Recently, unprecedentedly accurate data on the orbital motion of stars in the vicinity of the Sagittarius $ {\rm A^*}$ have been available. Such information can be used not only to constrain the mass of the supermassive black hole (SMBH) in…

The center of the Milky Way hosts a massive black hole. The observational evidence for its existence is overwhelming. The compact radio source Sgr A* has been associated with a black hole since its discovery. In the last decade,…

In accretion-based models for Sgr A* the X-ray, infrared, and millimeter emission arise in a hot, geometrically thick accretion flow close to the black hole. The spectrum and size of the source depend on the black hole mass accretion rate…

In this work, we studied the Galactic Center supermassive black hole (SMBH), Sagittarius A* (Sgr A*), with the KVN and VERA Array (KaVA)/East Asian VLBI Network (EAVN) monitoring observations. Especially on 13 May 2019, Sgr A* experienced…

Understanding the origin of the flaring activity from the Galactic center supermassive black hole, Sagittarius A*, is a major scientific goal of the NuSTAR Galactic plane survey campaign. We report on the data obtained between July 2012 and…