Related papers: Simultaneous Multi-Wavelength Observations of Sgr …

We present a spectrum of Sgr A* observed simultaneously on June 17, 2003 at wavelengths from 90 to 0.7 cm with the VLA. In the spectrum, we also include the measurements of Sgr A* observed on the same day with the GMRT at 49 cm, the SMA at…

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 present the results of a 3.3-year project to monitor the flux density of Sagittarius A* at 2.0, 1.3, and 0.7 cm with the VLA. The fully calibrated light curves for Sgr A* at all three wavelengths are presented. Typical errors in the flux…

We report the detection of variable emission from Sgr A* in almost all wavelength bands (i.e. centimeter, millimeter, submillimeter, near-IR and X-rays) during a multi-wavelength observing campaign. Three new moderate flares are detected…

The supermassive black hole Sagittarius A* (Sgr A*) exhibits temporal and spectral variability across the electromagnetic spectrum. However, variability at radio frequencies below ~ 5 GHz for timescales shorter than a day remains largely…

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…

Based on Bremer et al. (2011) and Eckart et al. (2012) we report on simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive…

We have performed monitoring observations of the 3-mm flux density toward the Galactic Center compact radio source Sgr A* with the Australia Telescope Compact Array since 2005 October. Careful calibrations of both elevation-dependent and…

We have performed the monitoring observations of flux density of Sagittarius A* at short millimeter wavelengths (100 and 140 GHz bands) on seven years in the period from 1996 to 2003 using the Nobeyama Millimeter Array (NMA). We found…

We report the results from recent observations of Sgr A* at short-/sub-millimeter wavelengths made with the partially finished Sub-Millimeter Array (SMA) on Mauna Kea. A total of 25 epochs of observations were carried out over the past 15…

We present a comprehensive data description for Ks-band measurements of Sgr A*. We characterize the statistical properties of the variability of Sgr A* in the near-infrared, which we find to be consistent with a single-state process forming…

To understand the correlation and the radiation mechanism of flare emission in different wavelength bands, we have coordinated a number of telescopes to observe SgrA* simultaneously. We focus only on one aspect of the preliminary results of…

The central region of the Galaxy has been observed at 580, 620 and 1010 MHz with the Giant Metrewave Radio Telescope (GMRT). We detect emission from Sgr-A*, the compact object at the dynamical centre of the Galaxy, and estimate its flux…

Context. The compact radio and near-infrared (NIR) source Sagittarius A* (Sgr A*) associated with the supermassive black hole in the Galactic center was observed at 7 mm in the context of a NIR triggered global Very Long Baseline Array…

The compact radio source at the center of our Galaxy, Sagittarius A* (Sgr A*), is the subject of intensive study as it provides a close-up view of an accreting supermassive black hole. Sgr A* provides us with a prototype of a low-luminosity…

Sgr A* exhibits flares in radio, millimeter and submm wavelengths with durations of $\sim 1$ hour. Using structure function, power spectrum and autocorrelation function analysis, we investigate the variability of Sgr A* on time scales…

Radio and mm-wavelength observations of Sagittarius A* (Sgr A*), the radio source associated with the supermassive black hole at the center of our Galaxy, show that it behaves as a partially self-absorbed synchrotron-emitting source. The…

We present first results of JWST Cycle 1 and 2 observations of Sgr A* using NIRCam taken simultaneously at 2.1 and 4.8 micron for a total of ~48 hours over seven different epochs in 2023 and 2024. We find correlated variability at 2.1 and…

The compact radio source Sgr\,A*, associated with the super massive black hole at the center of the Galaxy, has been studied with VLBA observations at 3 frequencies (22, 43, 86\,GHz) performed on 10 consecutive days in May 2007. The total…

We determine the characteristics of the 7mm to 20cm wavelength radio variability in Sgr A* on time scales from days to three decades. The amplitude of the intensity modulation is between 30 and 39% at all wavelengths. Analysis of uniformly…