Abstract
We describe the late spectral variability and flux evolution of TDF Sw J1644+57, a Tidal Disruption Flare which left the typical potential trend proportional to t(-5/3) in 2012, maintaining a quiescent flux until nowadays. Sixteen X-ray observations of ESA satellite XMM-Newton have been used in this study, including the one performed on 17th July, 2013. A search for optical emission in BOOTES/CASANDRA database has been performed too. Late X-ray fluxes show that the source flux decline does not follow the expected TDF trend at the time of the last XMM-Newton observation. Moreover, the spectra fitting parameters, in particular the neutral hydrogen column density, N_{H}, and the power-law index, Γ, indicate that the source darkening has diminished and that the spectral shape has flattened with time. The disruption of the star could have come to an end. Nevertheless, a quiescent X-ray flux continues. Evidence for a quiescent X-ray flux is presented.
