The first synchrotron jet resolved towards a post-AGB star

Övrigt konferensbidrag, 2014

Although bipolar and multipolar morphologies towards a number of post-asymptotic giant branch stars have been observed, not much is known about the mechanisms which lead to the launching and driven of the observed high-velocity, collimated outflows. Due to the scarcity of direct observational evidence, the actual mechanism shaping the circumstellar envelope of post-asymptotic giant branch stars is still unknown. In this talk, we present the results of radio continuum observations towards the post-asymptotic giant branch star IRAS 15445-5449. The measured flux density yield a steep negative spectral index, which is unambiguous signature of synchrotron radiation. We present the first resolved images of the synchrotron emission, and show that the emission originates in a collimated jet. This suggest that the high-velocity outflow is magnetically collimated. The close correspondence between the shape of the synchrotron emission and the bipolar shape of the object observed at other wavelenghts, suggest that the jet is responsible for the source morphology.