Q. Daniel Wang and Cornelia Lang (U. of Massachusetts) Eric Gotthelf (Columbia U.) Chandra X-ray Survey of the Galactic Center: On the Nature of the X-ray Emission Based partly on a paper published in Nature (Jan. 10th issue) and on a talk presented at the AAS meeting, Jan. 9, 2002

GC

ASCA Survey of the Galactic Center + Sakano et al. (2001)

2 o (900 light-year) 0.8 o (400 light-year) GC Chandra X-ray Survey of the Galactic Center

Red: 1-3 keV Green: 3-5 keV Blue: 5-8 keV GC

Central Region of the Survey

Radio Mid-infrared 6.4 keV line (fluorescent radiation) Galactic Center Across the Spectrum

Summary First high-resolution X-ray panorama of the Galactic center  separation of discrete and diffuse X-ray emissions. Detection of about 1,000 discrete X-ray sources  presence of numerous white dwarf stars, neutron stars, and black holes. Detection of large amounts of hot gas (tens of million degrees)  heated and chemically enriched by frequent supernovae and escaping into the Galactic halo. Map of the fluorescent (reflected) X-ray radiation  tracing the radiation history of the central supermassive black hole.

These results represent an important step toward the understanding the high-energy activities in the heart of the Milky Way as well as cores of galaxies throughout the Universe.