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≈0.3. The multi-ν spectral energy distribution (SED) of the object associated to the GRG core shows a synchrotron peak at ν≈1014 Hz consistent with the SED of a radio galaxy blazar-like core. The angular size of the lobes are ∼4′ for the NW lobe and ∼1.2′ for the SE lobe, corresponding to projected linear distances of ∼1078 kpc and ∼324 kpc, respectively. The best-fit parameters for the SED of the GRG core and the value of jet boosting parameter δ=2, indicate that the GRG jet has maximum inclination θ≈30 deg with respect to the line of sight, a value obtained for δ=Γ, while the minimum value of θ is not constrained due to the degeneracy existing with the value of Lorentz factor Γ. Given the photometric redshift z≈0.3, this GRG shows a core luminosity of P1.4GHz≈5.52×1024 W Hz−1, and a luminosity P1.4GHz≈1.29×1025 W Hz−1 for the NW lobe and P1.4GHz≈0.46×1025 W Hz−1 for the SE lobe, consistent with the typical GRG luminosities. The radio lobes show a fractional linear polarization ≈9% consistent with typical values found in other GRG lobes.
@article{arxiv.1511.08330,
title = {Discovery of a suspected giant radio galaxy with the KAT-7 array},
author = {S. Colafrancesco and N. Mhlahlo and T. Jarrett and N. Oozeer and P. Marchegiani},
journal= {arXiv preprint arXiv:1511.08330},
year = {2015}
}
Comments
7 pages, 6 figures, 2 tables, accepted for publication in MNRAS