相关论文: Chandra Spectral and Timing Analysis of Sgr A*'s B…

This paper presents the Suzaku results obtained for the Sagittarius (Sgr) C region using the concept of X-ray reflection nebulae (XRNe) as the echo of past flares from the super massive black hole, Sgr A*. The Sgr C complex is composed of…

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…

LkHA312 has been observed serendipitously with the ACIS-I detector on board Chandra with 26h continuous exposure. This H_alpha emission line star belongs to the star-forming region M78 (NGC2068). From the optical and NIR data, we show that…

A Chandra X-ray imaging observation of the jet in Pictor A showed a feature that appears to be a flare that faded between 2000 and 2002. The feature was not detected in a follow-up observation in 2009. The jet itself is over 150 kpc long…

We report on an observation of SGR 1627-41 made with the Chandra X-ray Observatory on 2011 June 16. Approximately three years after its outburst activity in 2008, the source's flux has been declining, as it approaches its quiescent state.…

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…

The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic Center, has long been examined in the radio-to-mm, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However,…

Sgr A* exhibits flares in the near-infrared and X-ray bands, with the luminosity in these bands increasing by factors of $10-100$ for $\approx 60$ minutes. One of the models proposed to explain these flares is synchrotron emission of…

Over the last decade, X-ray observations of Sgr A* have revealed a black hole in a deep sleep, punctuated roughly once per day by brief flares. The extreme X-ray faintness of this supermassive black hole has been a long-standing puzzle in…

In an intensive observational campaign in the 9 month duration of Chandra X-ray Visionary Project that was conducted in the year 2012, 39 large X-ray flares of Sgr A* were recorded. An analysis of the times of the observed flares reveals…

The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5-11 in the 1.3 millimeter wavelength band. At the same time, interferometric array data from the Atacama…

Sgr A* exhibits flaring in the infrared several times each day, occasionally accompanied by flaring in X-rays. The infrared flares are believed to arise through synchrotron emission from a transient population of accelerated electrons. The…

We report on the results of a ~30 ks Chandra pointing of the soft gamma-ray repeater SGR 1806-20, the first X-ray observation with high spectral resolution performed after the 2004 December 27 Giant Flare. The source was found in a bursting…

We present Event Horizon Telescope (EHT) 1.3 mm measurements of the radio source located at the position of the supermassive black hole Sagittarius A* (Sgr A*), collected during the 2017 April 5--11 campaign. The observations were carried…

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…

Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A* is remarkably faint in all wavebands other than the radio…

We report on X-ray observations made with the Rossi X-ray Timing Explorer of the black hole candidate (BHC) transient XTE J1650-500 at the end of its first, and currently only, outburst. By monitoring the source at low luminosities over…

We report on exploratory Chandra observations of five galactic nuclei that were found to be X-ray bright during the ROSAT all-sky survey (with L_X > 10^43 erg s^-1) but subsequently exhibited a dramatic decline in X-ray luminosity. Very…

In Spring 2011 we observed Sgr A*, the supermassive black hole at the center of our Galaxy, with XMM-Newton with a total exposure of ~226 ks in coordination with the 1.3 mm VLBI. We have performed timing analysis of the X-ray emission from…

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…