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Broadband Observations of the Gamma-ray Emitting Narrow Line Seyfert 1 Galaxy SBS 0846+513

We present the results of our broadband study of the $γ$-ray emitting narrow line Seyfert 1 (NLSy1) galaxy SBS 0846+513 ($z=0.585$). This includes multi-band flux variations, $γ$-ray spectral analysis, broad band spectral energy distribution (SED) modeling, and intranight optical variability (INOV) observations carried over 6 nights between 2012 November and 2013 March using the 2 m Himalayan Chandra Telescope and the 1.3 m telescope at Devasthal. Multiple episodes of flaring activity are seen in the $γ$-ray light curve of the source which are also reflected in the observations at lower frequencies. A statistically significant curvature is noticed in the seven years averaged $γ$-ray spectrum, thus indicating its similarity with powerful flat spectrum radio quasars (FSRQs). Modeling the SEDs with a one zone leptonic emission model hints the optical-UV spectrum to be dominated by synchrotron radiation, whereas, inverse Compton scattering of broad line region photons reproduces the $γ$-ray part of the SEDs. The source was found to be variable on all the six nights of optical observations with a variation of $\sim$0.3 magnitude within a single night, coinciding with a high $γ$-ray activity state. The observed large amplitude INOV clearly indicates the presence of a closely aligned beamed relativistic jet in SBS 0846+513. Our broadband study supports the recent claims in literature that $γ$-ray emitting NLSy1 galaxies are similar to blazars and constitute the low black hole mass counterparts to FSRQs.