The Peculiar Radio-Loud Narrow Line Seyfert 1 Galaxy 1H 0323+342

TL;DR

This study investigates the multi-wavelength emission and variability of the radio-loud NLSy1 galaxy 1H 0323+342, revealing complex emission regions, jet activity, and a high black hole spin, blending characteristics of FSRQs and NLSy1s.

Contribution

The paper provides a detailed multi-wavelength analysis of 1H 0323+342, modeling its SEDs and revealing dual characteristics of FSRQs and NLSy1s with implications for jet and accretion physics.

Findings

Gamma-ray flux doubling time as short as 3 hours during flares.

X-ray spectra indicate both thermal corona and non-thermal jet contributions.

High black hole spin of approximately 0.96 inferred from spectral analysis.

Abstract

We present a multi-wavelength study of the radio-loud narrow line Seyfert 1 galaxy (NLSy1), 1H 0323+342, detected by Fermi Gamma Ray Space Telescope. Multi-band light curves show many orphan X-ray and optical flares having no corresponding {\gamma}-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, {\gamma}-ray flux doubling time scale as small as $\sim$ 3 hours is noticed. We built spectral energy distribution (SED) during different activity states and modeled them using an one-zone leptonic model. The shape of the optical/UV component of the SEDs is dominated by accretion disk emission in all the activity states. In the X-ray band, significant thermal emission from the hot corona is inferred during quiescent and first flaring states, however, during subsequent flares, non-thermal jet component dominates. The {\gamma}-ray emission in all the states can be well explained by inverse-Compton scattering of accretion disk photons reprocessed by the broad line region. The source showed violent intra-night optical variability, coinciding with one of the high {\gamma}-ray activity states. An analysis of the overall X-ray spectrum fitted with an absorbed power-law plus relativistic reflection component hints for the presence of Fe K-{\alpha} line and returns a high black hole spin value of a=0.96 $\pm$ 0.14. We argue that 1H 0323+342 possesses dual characteristics, akin to flat spectrum radio quasars (FSRQs) as well as radio-quiet NLSy1s, though at a low jet power regime compared to powerful FSRQs.