A detailed study toward the Water fountain IRAS 15445-5449

Artikel i vetenskaplig tidskrift, 2017

Post-Asymptotic giant branch (post-ABG) sources with high-velocity spectral features of H2O maser emission detected toward their circumstellar envelopes (CSEs) are known as Water Fountain (WF) nebulae. These are low- or intermediate-mass Galactic stellar sources that are undergoing the late stages of an intense mass-loss process. The velocity and the spatial distribution of the H2O maser spectral features can provide information about the kinematics of the molecular gas component of their CSEs. Hence, observational studies toward WF nebulae could help to better understand the formation of the asymmetric structures (hundred to thousand AUs) commonly seen toward Planetary nebulae (PNe). Here we present preliminary results of observations done toward the WF IRAS 15445-5449 using the Australia Telescope Compact Array (ATCA) and the Very Large Telescope (SINFONI/VLT). Assuming that the pumping of the H2O maser transitions is a consequence of shocks between different velocity winds, the spatial distribution of the emission shed light on the scales of the regions affected by the propagation of the shock-fronts.