Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2001 June 7
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

NGC 253: X-Ray Zoom
Credit : K. Weaver (LHEA/ GSFC), et al.; X-ray Image: SAO, CXC, NASA; Optical Image: ESO

Explanation: Astronomers now report that Chandra X-ray Observatory observations of galaxies known to be frantically forming stars show that these galaxies also contain luminous x-ray sources -- thought to be intermediate mass black holes and immense clouds of superheated gas. Take the lovely island universe NGC 253 for example. At distance of a mere 8 million light-years, NGC 253's prodigious starforming activity has been well studied using high-resolution optical images like the one seen here at lower left. Zooming in on this energetic galaxy's central region, Chandra's x-ray detectors reveal hidden details indicated in the inset at right. In the false-color image, x-ray hot gas clouds glow near the core and at least four very powerful x-ray sources lie within 3,000 light-years of the center of the galaxy. Much more luminous than black hole binary star systems in our own galaxy, these extreme x-ray sources may be gravitating toward NGC 253's center. As a result, NGC 253 and other similar starforming galaxies could ultimately develop a single, central, supermassive black hole, transforming their cores into quasars.

Tomorrow's picture: Three Amigos

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.