Discovery of a suspected giant radio galaxy with the KAT-7 array

Abstract

We detect a new suspected giant radio galaxy (GRG) discovered by KAT-7. The GRG core is identified with the WISE source J013313.50-130330.5, an extragalactic source based on its infrared colors and consistent with a misaligned AGN-type spectrum at $z\approx 0.3$. The multi-$\nu$ spectral energy distribution (SED) of the object associated to the GRG core shows a synchrotron peak at $\nu \approx 10^{14}$ Hz consistent with the SED of a radio galaxy blazar-like core. The angular size of the lobes are $\sim 4^{\prime }$ for the NW lobe and $\sim 1.2^{\prime }$ for the SE lobe, corresponding to projected linear distances of $\sim 1078$ kpc and $\sim 324$ kpc, respectively. The best-fit parameters for the SED of the GRG core and the value of jet boosting parameter $\delta =2$, indicate that the GRG jet has maximum inclination $\theta \approx 30$ deg with respect to the line of sight, a value obtained for $\delta =\Gamma$, while the minimum value of $\theta$ is not constrained due to the degeneracy existing with the value of Lorentz factor $\Gamma$. Given the photometric redshift $z\approx 0.3$, this GRG shows a core luminosity of $P_{1.4GHz}\approx 5.52\times 10^{24}$ W Hz${}^{-1}$, and a luminosity $P_{1.4GHz}\approx 1.29\times 10^{25}$ W Hz${}^{-1}$ for the NW lobe and $P_{1.4GHz}\approx 0.46\times 10^{25}$ W Hz${}^{-1}$ for the SE lobe, consistent with the typical GRG luminosities. The radio lobes show a fractional linear polarization $\approx 9\%$ consistent with typical values found in other GRG lobes.

7 pages, 6 figures, 2 tables, accepted for publication in MNRAS

References in corpus (7)

• An Atlas of Galaxy Spectral Energy Distributions from the Ultraviolet to the Mid-Infrared
• A strong magnetic field in the jet base of a supermassive black hole
• On the relationship between a giant radio galaxy MSH 05-22 and the ambient large-scale galaxy structure
• Relativistic electrons and magnetic field of the M87 jet on ~ten Schwarzschild radii scale
• The new sample of giant radio sources II. Update of optical counterparts, further spectroscopy of identified faint host galaxies, high-frequency radio maps, and polarisation properties of the sources
• SZ effect from radio-galaxy lobes: astrophysical and cosmological relevance
• Early Science with the Karoo Array Telescope: a Mini-Halo Candidate in Galaxy Cluster Abell 3667

Cited by in corpus (4)

• The MeerKAT Galaxy Cluster Legacy Survey I. Survey Overview and Highlights
• An updated catalogue of giant radio sources
• Revealing the Unusual Structure of the KAT-7-Discovered Giant Radio Galaxy J0133$-$1302
• Giant radio quasars: composite optical spectra