source spectrum obtained in the present work from *Fermi*-LAT observations are described in Section 5.2.

*Swift*-XRT & UVOT data
-----------------------

During March 1, 2013 to April 15, 2013 (MJD 56352–56397) only six days of observations are available from *Swift* with XRT (X–Ray Telescope), covering the 0.3-10 keV energy band [@xrt05], and UVOT (UV/Optical Telescope), covering 180-600 nm wavelength range [@uvot05].

*Swift*-XRT data were reduced following the standard procedure[^2] using $FTOOLS$. The data were collected in window timing (WT) mode for all the observations. The task [xselect]{} (ver V2.4b) within the [HEASoft]{} package (v6.13) with recent calibration files (ver. 20120209) was used to analyse the data. The spectra and light curves of the source were extracted using a circular region with radius of $23^{\prime\prime}$ around the source. The spectra and light curves of nearby background region were extracted within an annulus with inner radius of $24^{\prime\prime}$ and outer radius of $45^{\prime\prime}$ around the source. The corresponding exposure maps and ancillary response files (ARFs) were generated using the tasks [xrtexpomap ]{} and [xrtmkarf]{} for all the observations, respectively. The spectra were binned using [grppha]{} to ensure a minimum of 20 counts per bin to perform the $\chi^2$ minimization for fitting the spectrum 