High energy activity of the super-massive black hole at the Galactic Center

Abstract

The center of our galaxy hosts the nearest super-massive black hole to the solar system, identified with the compact radio source Sgr A * . High energy experiments have tried in the past to detect the X/gamma-ray emission expected from the accretion of the surrounding material into this super-massive black hole. Only recently, however, thanks to the new generation of telescopes, it has been possible to reveal high energy radiation associated with Sgr A * or its close environment. I will review and discuss in particular the results on the Sgr A * X-ray flares discovered with Chandra and XMM-Newton, on the central soft gamma-ray source detected with INTEGRAL, and on the galactic center TeV emission revealed by HESS. To cite this article: A. Goldwurm, C. R. Physique 8 (2007). RésuméActivité à haute énergie du trou noir supermassif au Centre Galactique. Le centre de notre Galaxie abrite le trou noir supermassif le plus proche du système solaire, identifié à la source radio compacte Sgr A * . Plusieurs missions de haute énergie ont essayé, dans le passé, de détecter l'émission X et gamma attendue de l'accrétion de matière environnante dans ce trou noir supermassif. Toutefois seul récemment, et grâce aux nouvelles générations de télescopes, il a été possible de déceler du rayonnement de haute énergie associé à Sgr A * ou à son environnement proche. Je passerai en revue en particulier les résultats sur les sursauts X de Sgr A * découverts avec Chandra et XMM-Newton, sur la source centrale de rayons gamma mous détectée avec INTEGRAL et sur l'émission au TeV du centre galactique révélée par HESS. Pour citer cet article : A. Goldwurm, C. R. Physique 8 (2007).

On the tidal evolution of the orbits of low-mass satellites around black holes

“…The Galactic center is only ≈8 kpc from the Sun and therefore it is the nearest laboratory where we can study the environment of super-massive black holes in detail, see e.g. Alexander (2005), Goldwurm (2007).…”

An overview of the high-energy emission from the Galactic Center

“…In the recent years, with the launch of Chandra, XMM-Newton, INTEGRAL and Suzaku X-ray/gamma-ray observatories and with the operation of ground-based veryhigh-energy (VHE) gamma-ray observatories like HESS, this quest has led to some fundamental discoveries. I will summarise here these results, focussing on items other than Sgr A * emission, and updating my previous review works 2 on similar subject (Goldwurm 2006(Goldwurm , 2007(Goldwurm , 2009 by reporting the most recent findings and discussing the still open questions.…”

Some Notes About the Current Researches on the Physics of Relativistic Jets

“…In addition, the origin of the radio emission in LLAGN is still matter of debate, with articles supporting the jet emission and others favoring the star formation [e.g., (Chiaraluce et al, 2019;Algera et al, 2020;S et al, 2020;Webster et al, 2020;Radcliffe et al, 2021)]. Sgr A* generated a relativistic jet in the remote past [Myrs ago, e.g., (Cecil et al, 2021)], but surely not today [e.g., (Goldwurm, 2007;Ponti et al, 2017)]. Even if the radio and X-ray emission of LLAGN and Sgr A* is due to a jet, then the resulting plane might be a visualization of the self-similarity of the jet emission at radio and X-rays.…”