Astronomers have just made a fascinating new discovery. These are two galaxies considered to be being part of the objects the biggest in the Universe . Specifically, the two galaxies are referred to as giant radio galaxies or GRGs, and could be spotted through the use of an equally giant radio telescope located in South Africa. GRGs are known to be at least 22 times the size of the Milky Way, but the two new ones have been detected in any part of the sky.
According to Dr. Jacinta Delhaize, researcher at the University of Cape Town and the first author of the study, they discovered the two GRGs in a region of the sky with an area approximately equal to 4 times that of the full moon. She also explained that the probability of finding two GRGs in such a small area is less than 0.0003%. This means, according to her que these GRGs might be more common than you might think.
The article presenting the results of this study was published on January 18, 2021 in the journal Monthly Notices of the Royal Astronomical Society.
What are giant radio galaxies?
You may be wondering what characterizes giant radio galaxies when compared to normal galaxies . Obviously, the main difference comes from their size which is about 700 kilo-parsecs, that is to say 22 times larger than that of our galaxy, and their length exceeds 2.28 million light years. . As far as we know, these GRGs have been around for several hundred million years, so their radio jets have had time to assume "astronomical" proportions.
In thisRegarding the two new GRGs, scientists indicate that they are much larger than the regular GRGs. These two galaxies are special, according to Dr. Matthew Prescott, University of the Western Cape researcher and co-author, being among the biggest giants known. They are also among the 10% of the largest GRGs. He added that the two cosmic objects are over 2 mega-parsecs in diameter, or over 6.5 million light years, 62 times the size of the Milky Way.
Scientists were able to isolate the two newly discovered GRGs from a radio map of the sky produced by the MIGHTEE or MeerKAT International Gigahertz Tiered Extragalactic Exploration project. This project uses the MeerKAT radio telescope located in South Africa.
The MeerKAT radio telescope consists of 64 satellite dishes located in the Karoo region. We know thatit is the precursor of the SKA or Square Kilometre Array, a radio telescope that will be installed in both South Africa and Australia. Researchers hope the SKA will have enough power to reveal even more GRG.
Currently, scientists believe that there are only 831 GRGs existing in the Universe. Most galaxies are indeed elliptical galaxies with massive black holes.