Peculiar giant radio galaxy GRG-J223301+131502 investigated by researchers

A global staff of astronomers has performed radio and optical observations of a peculiar big radio galaxy generally known as GRG-J223301+131502. Outcomes of the observational marketing campaign shed extra gentle on the properties of this galaxy and have unveiled its distinctive jet construction. The findings are reported in a paper revealed September 26 on arXiv.org.

The so-called big radio galaxies (GRGs) are radio galaxies with an general projected linear size exceeding a minimum of 2.3 million gentle years. They’re uncommon objects grown in low-density environments. Usually, GRGs are vital for astronomers to check the formation and the evolution of radio sources.

Thus far, a few thousand GRGs have been detected, out of which solely ten exceed 10 million gentle years in dimension. The biggest one is J1420-0545—with a projected correct size of roughly 16 million gentle years. Subsequently, GRGs and likewise the remainder of the megaparsec-scale radio galaxies are assumed to be the most important single-galaxy–induced phenomena within the universe.

At a redshift of 0.093, GRG-J223301+131502 (GRG-J2233+1315 for brief) is a big radio galaxy first recognized in 2017 as a part of the Search and Evaluation of GRGs with Related Nuclei (SAGAN) undertaking. It has a total projected linear dimension of practically 5.57 million gentle years and is hosted by SDSSJ223301.30+131502.5—an S0-a kind galaxy exhibiting a giant diffuse stellar halo.

Earlier research of GRG-J2233+1315 have discovered that this galaxy is residing in a dense cluster surroundings, which is in distinction to the present theories that GRGs normally reside in a sparse surroundings. Subsequently, so as to confirm this, a bunch of astronomers led by Pratik Dabhade of Sorbonne College in Paris, France, carried out deep multi-frequency radio observations of GRG-J2233+1315 with the Big Metrewave Radio Telescope (GMRT) and Low-Frequency Array (LOFAR), in addition to spectroscopic observations utilizing the William Herschel Telescope (WHT).

The deep and high-resolution radio photographs disclosed an infinite jet, about 772,000 gentle years in dimension, emanating from the radio core of GRG-J2233+1315 and resulting in a “kink” extending some 326,000 gentle years. The photographs additionally present that the galaxy reveals lobes with none distinguished hotspots and intently resembles a barbell, therefore the researchers dubbed GRG-J2233+1315 the Barbell GRG. These detected lobes turned out to have magnetic area power of about 5 µG and spectral ages between 110 and 200 million years.

The observations discovered that the Barbell GRG has a redshift of roughly 0.99 and that its linear dimension is bigger than beforehand thought—virtually 6 million light years. The outcomes point out that the host galaxy has a comparatively low star formation price—at a stage of about 0.001 solar plenty per 12 months.

Summing up the outcomes, the authors of the paper underlined the significance of their findings for future research.

“The invention of the ∼ 100 kpc ‘kink’ construction from our examine gives a novel alternative for testing numerous MHD [magnetohydrodynamic] fashions on massive scales…. This GRG with two-sided, large-scale jets with a kink and diffuse outer lobes residing in a cluster surroundings, gives a possibility of exploring the construction and development of GRGs in different environments,” the researchers concluded.

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