News tagged with active galaxies

A new paradigm for active galactic nuclei

(Phys.org) -- Seyfert galaxies are similar to normal galaxies like our own Milky Way except in one critical respect: their nuclei are fantastically bright, in extreme instances as luminous as 100 billion suns. ...

Apr 24, 2012
5 / 5 (3) 4 | with audio podcast

Black holes and star formation

(PhysOrg.com) -- It has long been recognized that galaxy mergers or even close interactions can play a vital role in shaping the morphology of galaxies. One way they can do so, it is thought, is by triggering ...

Feb 09, 2012
4.1 / 5 (7) 7 | with audio podcast

Suspects in the quenching of star formation exonerated

Supermassive black holes millions to billions times the mass of our Sun lie at the heart of most, maybe all large galaxies. Some of these power brilliantly luminous, rapidly growing objects called active galactic nuclei that ...

Oct 11, 2011
4.4 / 5 (5) 2 | with audio podcast

What activates a supermassive black hole?

A new study combining data from ESO's Very Large Telescope and ESA's XMM-Newton X-ray space observatory has turned up a surprise. Most of the huge black holes in the centres of galaxies in the past 11 billion ...

Jul 13, 2011
4.7 / 5 (13) 108 | with audio podcast

How often do giant black holes become hyperactive?

(PhysOrg.com) -- A new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. This discovery clarifies how supermassive ...

Dec 20, 2010
5 / 5 (7) 19 | with audio podcast

Mergers Most Likely Fuel for Active Galaxies

(PhysOrg.com) -- The first solid evidence for how the center of some galaxies come to shine brightly while others barely flicker has been uncovered by researchers at the Kavli Institute for Particle Astrophysics ...

Jun 16, 2010
4.6 / 5 (10) 0 | with audio podcast

How do supermassive black holes get so big?

(PhysOrg.com) -- At the center of most galaxies lie supermassive black holes that can grow to become more than a billion times larger than our Sun. However, astrophysicists don’t fully understand the formation ...

Apr 26, 2010 weblog
4.2 / 5 (12) 1 | with audio podcast

Surveying the X-ray Sky

(PhysOrg.com) -- Astronomers have only modest laboratories to probe the mysteries of the cosmos. Mostly they have to rely on meticulous and clever observations of remote phenomena.

Jan 11, 2010
5 / 5 (6) 0 | with audio podcast