The Sgr B2 X-ray echo of the galactic center supernova explosion that produced Sgr A east

Christopher L. Fryer, Gabriel Rockefeller, Aimee Hungerford, Fulvio Melia

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Using a combination of one-dimensional and three-dimensional hydrodynamic simulations, we have carried out the first in-depth analysis of the remnant's evolution and its various interactions: with the stellar winds flowing out from the inner ∼2 pc; with the supermassive black hole, Sgr A*; and with the 50 km s-1 molecular cloud behind and to the east of the nucleus. We have found that, unlike previous estimates, a rather "standard" supernova explosion with energy ∼1.5 × 1051 ergs would have been sufficient to create the remnant we see today and that the latter is probably only ∼1700 yr old. We have found that the passage of the remnant across the black hole would have enhanced the accretion rate onto the central object by less than a factor of 2. Such a small increase cannot explain the current Fe fluorescence observed from the molecular cloud Sgr B2; this fluorescence would have required an increase in the luminosity of Sgr A* by 6 orders of magnitude several hundred years ago. Instead, we have uncovered what appears to be a more plausible scenario for this transient irradiation: the interaction between the expanding remnant and the 50 km s-1 molecular cloud. The first impact would have occurred about 1200 yr after the explosion, producing a 2-200 keV luminosity of ∼1039 ergs s -1. During the intervening 300-400 yr, the dissipation of kinetic energy subsided considerably, leading to the much lower luminosity (∼10 36 ergs s-1 at 2-10 keV) we see today.

Original languageEnglish (US)
Pages (from-to)786-796
Number of pages11
JournalAstrophysical Journal
Issue number2 I
StatePublished - Feb 20 2006


  • Acceleration of particles
  • Galaxy: center
  • Radiation mechanisms: nonthermal stars: winds, outflows
  • Supernova remnants
  • X-rays: diffuse background

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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