The radio source Sgr A has been mapped with the Very Large Array (VLA) at 6 and 20 cm with an angular resolution of 5″ × 8″ arc. In agreement with the earlier “WORST” map, the non-thermal source Sgr A East shows a shell structure, while the thermal source Sgr A West shows a spiral-like morphology.

2017年6月8日 · We present 44 and 226 GHz observations of the Galactic center within 20 " of Sgr A*. Millimeter continuum emission at 226 GHz is detected from eight stars that have previously been identified at near-IR and radio wavelengths.

Using VLA archival data for the H92alpha radio recombination line, we also investigated radial velocities in the LSR velocity range from +200 to -415 km s-1. Combining proper motion and radial velocity measurements, we have determined …

Today, Sgr A* is believed to be the site of a black hole about 2.6 million times more massive than the Sun. Don Backer and Dick Sramek observed Sgr A* with the VLA over 16 years, from 1982 to 1998, measuring its slow apparent motion across the sky. Their purpose was to …

We present 44 and 226 GHz observations of the Galactic Centre within 20 arcsec of Sgr A*. Millimetre continuum emission at 226 GHz is detected from eight stars that have previously been identified at near-IR and radio wavelengths.

Figure 8.15: NRAO VLA radio image of Sgr A West, which shows that the point source in the Galactic Center is surrounded by what appear to be spiral arms of gas that orbit this object. Credit: Roberts et al. NRAO / AUI ./

We perform three-dimensional numerical simulations to study the hydrodynamic evolution of Sgr A East, the only known supernova remnant (SNR) in the center of our Galaxy, to infer its debated...

We report progress on measuring the position of Sgr A* on infrared images, placing limits on the motion of the central star cluster relative to Sgr A*, and measuring the proper motion of Sgr A* itself. The position of Sgr A* has been determined to within 10 mas on infrared images.

This area is obscured by huge clouds of dust, but it can be seen in the radio wavelengths, which easily pass through the clutter (VLA image above). We can measure how fast our solar system is moving by observing how Sgr A* changes in relation to …

2006年12月1日 · We reviewed the multiple-wavelength spectrum of Sgr A*. The recent continuum spectrum was determined using data obtained from the Very Large Array (VLA), the Giant Metrewave Radio Telescope...