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 γ-ray counterparts. Such anomalous variability behavior can be due to different locations of the emission region from the central source. During a large flare, γ-ray flux doubling time scale as small as ∼ 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 γ-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 γ-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-α line and returns a high black hole spin value of a=0.96 ± 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.
Using data from the Wide-field Infrared Survey Explorer, we studied the mid-infrared (mid-IR) 3.4 μm (W1-band) and 4.6 μm (W2-band) flux variability of γ-ray emitting blazars. Our sample consists of 460 flat spectrum radio quasars (FSRQs) and 575 BL Lacertae (BL Lac) objects. On intraday time-scales, the median amplitude of variability (σm) for FSRQs is 0.04$^{+0.03}_{-0.02}$ and 0.05$^{+0.03}_{-0.02}$ mag in W1 and W2 bands. For BL Lacs, we found median σm in W1(W2) bands of 0.04$^{+0.01}_{-0.02}$ (0.04$^{+0.02}_{-0.02}$) mag. On long time-scales, for FSRQs we found a median σm of 0.44$^{+0.28}_{-0.27}$ and 0.45$^{+0.27}_{-0.27}$ mag in W1 and W2 bands, while for BL Lacs, the median values are 0.21$^{+0.18}_{-0.12}$ and 0.22$^{+0.18}_{-0.11}$ mag in W1 and W2 bands. From statistical tests, we found FSRQs to show larger σm than BL Lacs on both intraday and long time-scales. Among blazars, low synchrotron peaked sources showed larger σm compared to intermediate synchrotron peaked and high synchrotron peaked sources. The larger σm seen in FSRQs relative to BL Lacs on both intraday and long time-scales could be due to them having the most powerful relativistic jets and/or their mid-IR band coinciding with the peak of the electron energy distribution. BL Lacs have low power jets and the observational window too traces the emission from low-energy electrons, thereby leading to low σm. In both FSRQs and BL Lacs predominantly a bluer when brighter behaviour was observed. No correlation is found between σm and black hole mass.
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