Asymmetric distributions of H2O and SiO masers towards V627 Cas
  We performed simultaneous observations of the H2O 6(1,6) - 5(2,3) (22.235080
GHz) and SiO v= 1, 2, J = 1 - 0, SiO v = 1, J = 2 - 1, 3 - 2 (43.122080,
42.820587, 86.243442, and 129.363359 GHz) masers towards the suspected D-type
symbiotic star, V627 Cas, using the Korean VLBI Network. Here, we present
astrometrically registered maps of the H2O and SiO v = 1, 2, J = 1 - 0, SiO v =
1, J = 2 - 1 masers for five epochs from January 2016 to June 2018.
Distributions of the SiO maser spots do not show clear ring-like structures,
and those of the H2O maser are biased towards the north-north-west to west with
respect to the SiO maser features according to observational epochs. These
asymmetric distributions of H2O and SiO masers are discussed based on two
scenarios of a bipolar outflow and the presence of the hot companion, a white
dwarf, in V627 Cas. We carried out ring fitting of SiO v = 1, and v = 2 masers
and estimated the expected position of the cool red giant. The ring radii of
the SiO v = 1 maser are slightly larger than those of the SiO v = 2 maser, as
previously known. Our assumption for the physical size of the SiO maser ring of
V627 Cas to be the typical size of a SiO maser ring radius (\sim4 au) of red
giants yields the distance of V627 Cas to be \sim1 kpc.
