Unexpected disclosure of galactic nuclei

The majority of galactic nuclei contain supermassive black holes of millions or even billions of solar material. Materials in the vicinity of such black holes can accumulate in a hole of dust and gas around the black hole.

Active galactic nuclei (AGNs) are one of the most impressive and interesting phenomena in astronomy astronomy, and are also very difficult to understand.

Because AGN plays an important role in the development of galaxies, astronomers are studying galaxies with AGN at a certain distance in the universe.

AGN plays an important role in the development of galaxies.(Image source: phys).

It was in the previous period of the universe, about ten billion years after the big bang, when the most powerful explosion of the AGN was supposed to happen. But AGNs at these distances are also fuzzy and harder to find.

Historically, they have been discovered because they are very red in color due to heavy dust obscuring, characteristic emission lines (very hot gas signals), or changing their characteristic activity.

CfA astronomers Matt Ashby, Steve Willner and Giovanni Fazio and two colleagues used 14-year-old infrared peripheral surveys, using the IRAC on the Spitzer Space Telescope to search AGN is far away. Various surveys in the archives continuously scan different parts of the sky over eleven epochs in their efforts to look deeper and further into the universe.

Astronomers find nearly a thousand infrared galaxies in these surveys, about one percent of all galaxies are recorded. They estimate that about eighty percent of these energy variable sources are AGNs, others are due to or indeterminate phenomena.