Discovery of a small diameter young supernova remnant G354.4+0.0
  We report discovery of a shell like structure G354.4+0.0 of size 1.6' that
shows morphology of a shell supernova remnant. Part of the structure show
polarized emission in NRAO VLA sky survey (NVSS) map. Based on 330 MHz, 1.4 GHz
Giant Metrewave Radio Telescope (GMRT) observations and existing observations
at higher frequencies, we conclude the partial shell structure showing
synchrotron emission is embedded in an extended HII region of size ~4'. The
spectrum of the diffuse HII region turns over between 1.4 GHz and 330 MHz. HI
absorption spectrum shows it to be located more than 5 kpc away from Sun. Based
on morphology, non-thermal polarized emission and size, this object is one of
the youngest supernova remnants discovered in the Galaxy with an estimated age
of about 100-500 years.
