Radio galaxies are amazing star systems that are surrounded by giant gas and dust clouds that are active in certain bands. Recently, the South African MeerKAT telescope has discovered a new representative of this class of space objects.
About radio galaxies
An international team of astronomers used the MeerKAT radio telescope to study giant radio galaxies as part of the Cosmological Evolution Survey (COSMOS) project. They have found a new giant radio galaxy that has not been previously reported. The finding was presented in a scientific paper published on November 11 on the arXiv preprint server.
So-called giant radio galaxies (GRGs) are radio galaxies whose total projected linear length exceeds at least 2.3 million light-years. These are rare objects that grow typically in low-density environments and have been observed to contain jets and plasma particles that emit synchrotrons. GRGs are important to astronomers in studying the formation and evolution of radio emission sources.
Discovery of a new radio galaxy
The MeerKAT radio interferometer, located in South Africa, is an amazing instrument for reviving GRGs at high frequencies (around 1.0 GHz). The same team of astronomers on spacecraft with Kathleen Charlton of the University of Cape Town in South Africa used MeerKAT to move the home GRGs to the COSMOS range. The domain was auditioned as part of the International GHz Tiered Extragalactic Exploration (MIGHTEE) with the complementary MeerKAT telescope.
“We have presented spatially-resolved spectral index and age maps of three GRGs within the COSMOS field using MIGHTEE L-band data and new MeerKAT UHF band observations,” the researchers wrote in the paper.
Charlton’s team studied three giant radio galaxies with the MeerKAT telescope. One appeared to be identified for the first time and was designated MGTC J100022.85+031520.4.
Parameters of the newly discovered galaxy
According to the study, MGTC J100022.85+031520.4 is located in the elliptical galaxy SDSS J100022.85+031520 with a redshift of about 0.1034. The projected linear size of the new GRG is about 4.2 million light-years, its mass is 93 trillion solar masses, and its total power is 597 ZW/Hz at 1284 MHz.
The collected data indicate that MGTC J100022.85+031520.4 has a dynamical age of about one billion years and its jet has a power at the level of one million quanta.
The observations revealed that MGTC J100022.85+031520.4 is the central galaxy and the brightest cluster galaxy (BCG) in the WHL J100022.9+031521 galaxy cluster. Thus, it is one of only 4% GRGs known to be in a cluster environment.
Summarizing the results, the authors of the paper noted that MGTC J100022.85+031520.4’s location at the center of the cluster and the observed curved morphology in the upper particle suggest that it has similar properties to galaxies that contain wide-angle tail (WATs) radio sources.
In general, WATs are powerful and often located at the centers of galaxy clusters, where intracluster medium pressure can bend the petals into the characteristic C-shape.
Provided by phys.org
