Black holes from small galaxies can create gamma rays

Black holes from small galaxies can create gamma rays

Blazars jet out of black holes in their centers.

In cosmology, there is a rule: if something strange happens in deep space, then most often the responsibility lies on a black hole. This also applies to the discovery of 7 galaxies, which can potentially change our understanding of the galactic size and behavior of the central black hole.

There is an opinion that only massive galaxies have enough energy to become blazars - colossal jets of radiation, powerful enough to stretch for thousands of light years. However, recent studies show that smaller galaxies are also capable of such, if the necessary conditions exist.

There are 3 main galactic types: oval elliptical, disk helix and irregular. The first are considered the most ancient and massive. It is believed to form when a collision of two smaller galaxies. As a rule, they contain a black hole, whose mass exceeds the solar one billion times.

Due to gravity, central black holes absorb material and grow. Accretion is involved in this process and a disk is created around the black hole. It begins to release extreme energy bursts in the radio, infrared or x-ray bands. In this case, the galaxy is considered “active”. Blazar is one of the varieties of the active galaxy. These are the ones that contain a supermassive black hole, capable of accelerating particles to almost luminous speed and keeping them in collimated narrow rays (jets) that seem incredibly bright if they are directed in our direction. These jets are considered one of the most extreme sources of gamma rays.

Jets of blazars resemble fountains. To create something similar, blazars must have a powerful engine - a massive black hole in the center. The Milky Way is a spiral-type galaxy with sleeves of gas and dust, as well as a bright center of ancient stars. Most often, spiral galaxies are inferior in mass and activity to an elliptical type.

Physicists were greatly surprised when the Fermi telescope launched in 2008 recorded gamma rays from 4 spiral galaxies in the first year of the orbital path. Many thought it was blazars. But then doubts arose that perhaps we were faced with an exception to the rule.

The question remained in force until a list of active spiral galaxies appeared in 2017. This group was called Seyfert galaxies, in the centers of which there are small black holes. But instead of emitting powerful gamma flares, they are characterized by strong UV rays. Then a new question arose: can a spiral galaxy emit gamma rays? The catalog contained 11101 Seyfert galaxies, which were studied in the gamma range using data from the Fermi satellite telescope. It turned out that 4 previous galaxies and 3 new ones that were considered blazars belong to the Seyfert type. This is an important breakthrough, because it shows that even small sources can release powerful gamma rays.

To understand the elliptical / spiral nature of these 7 galaxies, scientists plan to get deeper images at the highest resolution. This is possible with a 10.4-meter reflecting Big Canary telescope, which began observations in 2007. In the next decade, it will surpass the new 30-meter TMT receiver. The new mirror will allow you to display the space 10 times better than the capabilities of the Hubble telescope allow.

The researchers also plan to use the Hubble Space Telescope to look into the bright centers of 7 sources and understand what type they are. It is important to study the environment of supermassive black holes and understand how blazars behave at other frequencies. The study of these issues will allow a better understanding of the evolution of the universe.

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