Beyond The Veil: The Search for Hidden Black Holes, a.k.a. Type 2 Quasars

Recent Headlines
AGN
An artist's rendition of a galaxy with a supermassive black hole at its core. Such a galaxy is called an Active Galactic Nucleus (AGN) (Credit: NASA)
Episode 2
March 27, 2000 :: According to the unified model for AGNs, it all depends on your point of view. The central black hole is assumed to be surrounded by a thick donut-shaped cloud of gas and dust. The source looks different, depending on whether it is observed from the side through the edge of the donut (Type 2), or from the top through the hole (Type 1).

The unified model explains many of the observations of active galaxies, and has won widespread acceptance among astronomers, though questions remain. Chief among these is whether this unified model applies to quasars whose central black hole is at least a thousand times more energetic than the typical AGN. Could a cloud of gas exist for any length of time around a giant black hole that is generating energy at such a prodigious rate?
Superman Episode 1
March 20, 2000 :: Could giant black holes be hiding in the centers of galaxies that lead double lives, appearing as mild-mannered "Clark Kent-like" normal galaxies in visible light, but revealing a powerful "Superman-like" inner core in X-rays? More


To be continued...

Next week find out why astronomers NEED Type 2 quasars!


Return to Chandra Chronicles

Highlights and Feature Stories from the Chandra Project
Archived reports of past Chandra Chronicles
Receive the Chandra Digest
Updated: April 24, 2007