2002/07/31 by A. Goldwurm, E. Brion, P. Goldoni +5 · 7 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/345749
published as Astrophys.J.584:751-757,2003 · 18 pages, 6 color figures, final version, accepted on October 24, 2002, to appear in ApJ, v584 n2 ApJ February 20, 2003 issue
arxiv created 2002/12/02 · openalex publication_date 2003/02/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
Sgr A*, the compact radio source believed to be the counterpart of the massive black hole at the Galactic nucleus, was observed to undergo rapid and intense flaring activity in X-rays with Chandra in 2000 October. We report here the detection with XMM-Newton European Photon Imaging Cameras of the early phase of a similar X-ray flare from this source, which occurred on 2001 September 4. The source 2-10 keV luminosity increased by a factor of ≈20 to reach a level of 4 × 10 34 ergs s -1 in a time interval of about 900 s, just before the end of the observation. The data indicate that the source spectrum was hard during the flare. This XMM-Newton observation confirms the results obtained by Chandra and suggests that in Sgr A* rapid and intense X-ray flaring is not a rare event. This can constrain the emission mechanism models proposed for this source and also implies that the crucial multiwavelength observation programs planned to explore the behavior of the radio/submillimeter and hard X-ray/gamma-ray emissions during the X-ray flares have a good chance of success.