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X-Ray Diagnostics of Giant Molecular Clouds in the Galactic Center Region and Past Activity of Sgr A*
- Source :
- The Astrophysical Journal
- Publication Year :
- 2011
- Publisher :
- The American Astronomical Society, 2011.
-
Abstract
- Strong iron fluorescence at 6.4 keV and hard-X-ray emissions from giant molecular clouds in the Galactic center region have been interpreted as reflections of a past outburst of the Sgr A* supermassive black hole. Careful treatment of multiple interactions of photons in a complicated geometry is essential to modeling the reprocessed emissions from the dense clouds. We develop a new calculation framework of X-ray reflection from molecular clouds based on Monte Carlo simulations for accurate interpretation of high-quality observational data. By utilizing this simulation framework, we present the first calculations of morphologies and spectra of the reflected X-ray emission for several realistic models of Sgr B2, which is the most massive molecular cloud in our Galaxy. The morphology of scattered hard X-rays above 20 keV is significantly different from that of iron fluorescence due to their large penetrating power into dense regions of the cloud, probing the structure of the cloud. High-resolution spectra provide quantitative evaluation of the iron line including its Compton shoulder to constrain the mass and the chemical composition of the cloud as well as the luminosity of the illuminating source. These predictions can be checked in the near future with future X-ray missions such as NuStar (hard X-rays) and ASTRO-H (both iron lines and hard X-rays).<br />28 pages, 15 figures, accepted for publications in ApJ
- Subjects :
- High Energy Astrophysical Phenomena (astro-ph.HE)
Physics
Supermassive black hole
Photon
Astrophysics::High Energy Astrophysical Phenomena
Molecular cloud
Galactic Center
FOS: Physical sciences
Astronomy and Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Astrophysics - Astrophysics of Galaxies
Galaxy
Spectral line
Luminosity
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Astrophysics - High Energy Astrophysical Phenomena
Astrophysics::Galaxy Astrophysics
Line (formation)
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 740
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal
- Accession number :
- edsair.doi.dedup.....92f204538beaa6417f5b245bcae91f4b