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arXiv · 1907.12765

The filamentary radio lobes of the Seyfert-Starburst composite galaxy NGC3079

Biny Sebastian·Preeti Kharb·C. P. O Dea·E. J. M. Colbert·S. A. Baum
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Abstract

We present results from multi-frequency polarization-sensitive Very Large Array observations of the Seyfert-starburst composite galaxy NGC3079. Our sensitive radio observations reveal a plethora of radio filaments comprising the radio lobes in this galaxy. We analyze the origin of these radio filaments in the context of existing Chandra X-ray and HST emission-line data. We do not find a one-to-one correlation of the radio filaments with the emission line filaments. The north-eastern lobe is highly polarized with polarization fractions $\sim$33% at 5 GHz. The magnetic fields are aligned with the linear extents of the optically-thin filaments, as observed in our, as well as other observations in the literature. Our rotation measure images show evidence for rotation measure inversion in the north-eastern lobe. Our data best fit a model where the cosmic rays follow the magnetic field lines generated as a result of the dynamo mechanism. There could be additional effects like shock acceleration that might also be playing a role. We speculate that the peculiar radio lobe morphology is a result of an interplay between both the superwinds and the AGN jet that are present in the galaxy. The jet, in fact, might be playing a major role in providing the relativistic electron population that is present in the radio lobes.

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Biny Sebastian, Preeti Kharb, C. P. O Dea, E. J. M. Colbert, S. A. Baum. 2019-07-30. The filamentary radio lobes of the Seyfert-Starburst composite galaxy NGC3079. https://doi.org/10.3847/1538-4357%2Fab371a

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