  A detailed study of the BL Lacertae PKS 0903-57 has been done for the first
time with 12 years of Fermi Large Area Telescope data. We have identified two
bright gamma-ray flares in 2018 and 2020. Many sub-structures were observed
during multiple time binning of these flares. We have performed detailed
temporal and spectral study on all the sub-structures separately. A single-zone
emission model is used for time-dependent leptonic modeling of the
multi-wavelength spectral energy distributions. Our estimated values of
variability time scale, magnetic field in the emission region, jet power
obtained from leptonic modeling of PKS 0903-57 are presented in this work.
Currently, we have a minimal number of observations in X-rays and other bands.
Hence, more simultaneous multi-wavelength monitoring of this source is required
to have a better understanding of the physical processes happening in the jet
of the blazar PKS 0903-57.
