active galactic nuclei tagged posts

Gamma-ray flares from blazars can be accompanied by high-energy neutrino emission. To better understand this phenomenon, an international research team has statistically analyzed 145 bright blazars. They constructed weekly binned light curves and utilized a Bayesian algorithm, finding that their sample was dominated by blazars with low flare duty cycles and energy fractions. The study suggests that high-energy neutrinos of blazars might be produced mainly during the flare phase.

Blazars ...

While studying a nearby pair of merging galaxies using the Atacama Large Millimeter/submillimeter Array (ALMA) – an international observatory co-operated by the U.S. National Science Foundation’s National Radio Astronomy Observatory (NRAO) – scientists discovered two supermassive black holes growing simultaneously near the center of the newly coalescing galaxy. These super-hungry giants are the closest together that scientists have ever observed in multiple wavelengths. What’s more, the new research reveals that binary black holes and the galaxy mergers that create them may be surprisingly commonplace in the Universe...

Black holes with varying light signatures but that were thought to be the same objects being viewed from different angles are actually in different stages of the life cycle, according to a study led by Dartmouth researchers.

The research on black holes known as “active galactic nuclei,” or AGNs, says that it definitively shows the need to revise the widely used “unified model of AGN” that characterizes supermassive black holes as all having the same properties.

The study, published in The Astrophysical Journal Supplement Series, provides answers to a nagging space mystery and should allow researchers to create more pre...

An artist’s impression of what an active galactic nucleus might look like close up. The accretion disk produces the brilliant light in the center. The broad-line region is just above the accretion disk and lost in the glare. Dust clouds are being driven upward by the intense radiation. Credit: Peter Z. Harrington

Mysterious features seen in light emitted from active galactic nuclei may be due to partial obscuration by dust clouds. Many large galaxies have a bright central region called an active galactic nucleus (AGN), powered by matter spiraling into a supermassive black hole...