The discovery of seven new giant galaxies outside the milkyway by Mexican astronomers. Observed by radio images provided by two astronomical radio surveys. The galaxies were known as Giant radio galaxies (GRG).
These galaxies considered to be radio galaxies with linear length overreach at 3.3 million light years. For astronomers the radio galaxies are important to study and identify the expansion of radio sources. Rare objects develop in low density environments. Jonatan Rentería Macario of the Autonomous University of Zacatecas and Heinz Andernach of the University of Guanajuato have analyzed images available in two recent radio surveys covering large areas of sky.
The data provided by the Jansky Very Large Array (JVLA) 1-2 GHz Snapshot Survey of SDSS Stripe82. The 150-MHz LOFAR Two-metre Sky Survey Preliminary Data Release LoTSS-PDR allowed the researchers to distinguish an impressive number. More than 2,000 extended features suggesting the presence of large radio galaxies. As a result, they confirmed the existence of seven new GRGs.
“For our search, we selected two recent radio surveys that cover large areas of sky. Here, we report the discovery of seven new GRGs in two recent surveys, the JVLA 1-2 GHz Snapshot Survey of SDSS Stripe82 and the 150-MHz LOFAR Two-metre Sky Survey Preliminary Data Release (LoTSS-PDR),” the authors explains.
The smallest GRG discovered is J0152+0015 with size of 3.35 million light years
The JVLA Snapshot Survey detected two of the seven new GRGs and other GRG’s found when data provided by LoTSS-PDR. The size of about 8.44 million light years designated J1301+5105. Making it one of the biggest giant radio galaxies known to date. Approximately, 16 million light years with projected size discovered J1420-0545 considered the largest giant radio galaxy discovered so far.
Moreover, the smallest GRG discovered is J0152+0015 with size of 3.35 million light years. The rest of the giant radio galaxies reported sizes ranging from 4.08 to 5.09 million light years.
Further, the researchers noted that their discovery proved that visual inspection of radio images is a successful method for finding new GRGs.
“Our results show that current and forthcoming low-frequency surveys with excellent sensitivity to low surface brightness features have a large potential to discover significant amounts of giant radio galaxies as well as sources of complex or currently unknown types of morphologies,” the authors concluded.