Thermal Emissions Spanning the Prompt and the Afterglow Phase of the Ultra-long GRB 130925A

Understand

GRB 130925A is an ultra-long GRB, and it shows clear evidences for a thermal emission in the soft X-ray data of \emph{Swift}/XRT ($\sim0.5$\,keV), lasting till the X-ray afterglow phase.

• Due to the long duration of the GRB, the burst could be studied in hard X-rays with high-resolution focusing detectors (\emph{NuSTAR}).
• The blackbody temperature, as measured by the \emph{Swift}/XRT, shows a decreasing trend till the late phase (Piro et al.
• 2014) whereas the high-energy data reveals a significant blackbody component during the late epochs at an order of magnitude higher temperature ($\sim5$\,keV), as compared to the contemporaneous low energy data (Bellm et al.