Related papers: Simultaneous Multi-Wavelength Observations of Sgr …

(abridged) We describe highlights of the results of two observing campaigns in 2004 to investigate the correlation of flare activity in Sgr A* in different wavelength regimes, using a total of nine ground and space-based telescopes. We…

We present and analyze ALMA submillimeter observations from a multi-wavelength campaign of Sgr A* during 18 July 2019. In addition to the submillimeter, we utilize concurrent mid-IR (Spitzer) and X-ray (Chandra) observations. The…

We report the detection and analysis of a radio flare observed on 17 April 2014 from Sgr A* at $9$ GHz using the VLA in its A-array configuration. This is the first reported simultaneous radio observation of Sgr A* across $16$ frequency…

Emission from Sgr A* is highly variable at both X-ray and infrared (IR) wavelengths. Observations over the last ~20 years have revealed X-ray flares that rise above a quiescent thermal background about once per day, while faint X-ray flares…

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…

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…

We report on the final two days of a multiwavelength campaign of Sgr A* observing in the radio, submillimeter, infrared, and X-ray bands in July 2019. Sgr A* was remarkably active, showing multiple flaring events across the electromagnetic…

In this paper we examine properties of the variable source Sgr A* in the near-infrared (NIR) using a very extensive Ks-band data set from NACO/VLT observations taken 2004 to 2009. We investigate the variability of Sgr A* with two different…

We report on the first simultaneous near-infrared/X-ray detection of the Sgr A* counterpart which is associated with the massive black hole at the center of the Milky Way. The observations have been carried out using the NACO adaptive…

This paper reports measurements of Sgr A* made with NACO in L' -band (3.80 um), Ks-band (2.12 um) and H-band (1.66 um) and with VISIR in N-band (11.88 um) at the ESO VLT, as well as with XMM-Newton at X-ray (2-10 keV) wavelengths. On 4…

Sgr A*, the massive black hole at the center of the Galaxy, varies in radio through X-ray emission on hourly time scales. The flare activity is thought to arise from the innermost region of an accretion flow onto Sgr A*. We present…

Sgr A* is variable at radio and submillimeter wavelengths on hourly time scales showing time delays between the peaks of flare emission as well as linearly polarized emission at millimeter and sub-mm wavelengths. To determine the…

The radiative counterpart of the supermassive black hole at the Galactic center (GC), Sgr A*, is subject to frequent flares visible simultaneously in X-rays and near-infrared (NIR). Often, enhanced radio variability from centimeter to…

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…

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 first systematic analysis of the X-ray variability of Sgr A* during the Chandra X-ray Observatory's 2012 Sgr A* X-ray Visionary Project (XVP). With 38 High Energy Transmission Grating Spectrometer (HETGS) observations spaced…

We examine time-dependent 2D relativistic radiation MHD flows to develop the shock oscillation model for the long-term flares of Sgr A*. Adopting modified flow parameters in addition to the previous studies, we confirm quasi-periodic flares…

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…

Monitoring of Sagittarius A* from X-ray to radio wavelengths has revealed structured variability --- including X-ray flares --- but it is challenging to establish correlations between them. Most studies have focused on variability in the…

We observed Sgr A* using the Very Large Array (VLA) and the Giant Metrewave Radio Telescope (GMRT) at multiple cm and mm wavelengths on 17 June 2003. The measured flux densities of Sgr A*, together with those obtained from the Submillimeter…