Speaker
Description
A new method (PSF method) for measuring photometries of moderately saturated UVOT sources has been proposed, which increases the dynamic range of UVOT. The brightest UV/optical flash was discovered in GRB 2201101A with the PSF method. Considering the very rapid brightening stage, the scenario of a refresh shock is adopted to explain the optical flash. In addition, we proposed a method (clean extraction) to remove the second-order contamination from UVOT UV grism spectra, increasing the effective wavelength range to about 4000 angstroms. A catalog is being constructed to reveal the temporal and spectral behavior of GRBs at the early stage with the clean extraction, the PSF method and simultaneous X-ray observations. Some preliminary results will be shown.
