active galactic nucleus (AGN) tagged posts

By analyzing the images of the Sombrero Galaxy obtained with the Hubble Space Telescope (HST), Elio Quiroga Rodriguez of the Mid Atlantic University in Spain, has identified a peculiar object, which turned out to be a galaxy hosting an active galactic nucleus (AGN). The finding was reported in a paper published August 11 on the pre-print server arXiv.

An AGN is a compact region at the center of a galaxy, more luminous than the surrounding galaxy light. Studies show that AGNs are very energetic due either to the presence of a black hole or star formation activity at the core of the galaxy.

Astronomers generally divide AGNs into two groups based on emission line features...

Star-forming galaxies are responsible for creating gamma-rays that until now had not been associated with a known origin, researchers from The Australian National University (ANU) have confirmed.

Lead author Dr. Matt Roth, from the ANU Research School of Astronomy and Astrophysics, said until now it has been unclear what created gamma-rays—one of the most energetic forms of light in the Universe—that appear in patches of seemingly “empty sky.”

The discovery could offer clues to help astronomers solve other mysteries of the Universe, such as what kind of particles make up Dark Matter—one of the holy grails of astrophysics.

“It’s a significant milestone to finally discover the origins of this ga...