Marco Fatuzzo and Fulvio Melia 2003 ApJ 596 1035 doi:10.1086/378041
Marco Fatuzzo1 and Fulvio Melia2
Show affiliationsSgr A East appears to be a single, mixed-morphology 10,000 yr old supernova remnant (SNR) at the Galactic center. It also appears to belong to a class of remnants that have been observed and detected at 1720 MHz, the transition frequency of OH maser emission. However, if the EGRET source 3EG J1746-2852, coincident with the Galactic center, is itself associated with this object, it would endow it with a γ-ray luminosity almost 2 orders of magnitude greater than that of the other EGRET-detected SNRs. We here reconsider the viability of a pion-production mechanism as the source of the broadband emission observed from Sgr A East, and show that what connects these objects—and ultimately also accounts for their different γ-ray emissivity—is the very important interaction between the expanding SNR shell and the surrounding molecular cloud environment. The singularly high γ-ray luminosity of Sgr A East, as well as its unusually steep radio spectral index, can thereby be attributed to the high-density (nH = 103 cm-3), strongly magnetized (B ~ 0.18 mG) environment in which it is located.
acceleration of particles; cosmic rays; Galaxy: center; gamma rays: theory; radiation mechanisms: non-thermal; supernova remnants
Issue 2 (2003 October 20)
Received 2003 February 16, accepted for publication 2003 June 24
Marco Fatuzzo and Fulvio Melia 2003 ApJ 596 1035
Kurtis A. Williams and Michael Bolte 2007 The Astronomical Journal 133 1490
Y. Damerdji et al. 2007 The Astronomical Journal 133 1470
Béla Szilágyi et al 2007 Class. Quantum Grav. 24 S275
Basmah Riaz et al. 2009 ApJ 705 1173
Kim D Anderson 2009 J. Neural Eng. 6 055003
W.-C. Müller and A. Busse 2007 EPL 78 14003
Valeri V. Makarov 2003 The Astronomical Journal 126 1996
J. Maíz Apellániz 2008 ApJ 677 1278
Aldo M. Serenelli et al 2009 ApJ 705 L123