Short time flux variability of water masers in W49 N using KaVA data

Abstract

We investigated flux variability of 22 GHz water masers in W49 N, which have been observed for three epochs in the early year of 2017 using KaVA. We used angular resolution and Doppler velocity conditions to specify the identical maser features in each epoch. The flux variability of water masers was defined as the ratio of flux intensity varied by increasing more than five times of the first epoch and to be found as the features in all three epochs. We found three bright features with their weighted local standard of rest (LSR) velocities at -92.25±0.56, -19.28±0.26 and +64.81±0.32 km s-1. Two features were located in the blueshifted and a feature in the redshifted outflows. To understand the environment of the W49 N star forming region, we, therefore, consider the distribution of water masers compared to other thermal molecular line emissions.