Searching Extra-tidal Features around the Globular Cluster Whiting 1
  Whiting 1 is a faint and young globular cluster in the halo of the Milky Way,
and was suggested to have originated in the Sagittarius spherical dwarf galaxy
(Sgr dSph). In this paper, we use the deep DESI Legacy Imaging Surveys to
explore tentative spatial connection between Whiting 1 and the Sgr dSph. We
redetermine the fundamental parameters of Whiting 1 and use the best-fitting
isochrone (age $\tau$=6.5 Gyr, metalicity Z=0.005 and $\rm d_{\odot}$=26.9 kpc)
to construct a theoretical matched filter for the extra-tidal features
searching. Without any smooth technique to the matched filter density map, we
detect a round-shape feature with possible leading and trailing tails on either
side of the cluster. This raw image is not totally new compared to old
discoveries, but confirms that no more large-scale features can be detected
under a depth of r<=22.5 mag. In our results, the whole feature stretches
0.1-0.2 degree along the orbit of Whiting 1, which gives a much larger area
than the cluster core. The tails on both sides of the cluster align along the
orbital direction of the Sgr dSph as well as the cluster itself, which implies
that these debris are probably stripped remnants of Whiting 1 by the Milky Way.
