Latest Issue of Science News


News

Hidden black holes

Astronomers have new evidence that a majority of the biggest black holes in the universe lie hidden behind thick veils of dust.

Monster black holes, which reside at the centers of galaxies, betray their presence when their immense gravity induces surrounding matter to generate a brilliant beacon of light known as a quasar. Models of the quasar light suggest that these beacons make a large contribution to the overall X-ray glow of the sky. However, the number of individual quasars actually observed in X-ray and visible-light studies falls far short of the expected population.

Researchers have proposed that the shortfall comes about because many quasars are shrouded by their own dusty rings or because they reside in dust-drenched galaxies that keep the beacons' visible light and even their X rays hidden from astronomers.

Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.

X
This article is available only to subscribing members. Join SSP today or Log in.