Hydrodynamical simulations of the jet in the symbiotic star MWC 560^*

I. Structure, emission and synthetic absorption line profiles

¹ Landessternwarte Heidelberg, Königsstuhl, 69117 Heidelberg, Germany e-mail: M.Stute@lsw.uni-heidelberg.de
² Institute of Astronomy, ETH Zentrum, 8092 Zurich, Switzerland

Received: 24 May 2004
Accepted: 25 August 2004

Abstract

We performed hydrodynamical simulations with and without radiative cooling of jet models with parameters representative of the symbiotic system MWC 560. For symbiotic systems we have to perform jet simulations of a pulsed underdense jet in a high density ambient medium. We present the jet structure resulting from our simulations and calculate emission plots which account for expected radiative processes. In addition, our calculations provide expansion velocities for the jet bow shock, the density and temperature structure in the jet, and the propagation and evolution of the jet pulses.
In MWC 560 the jet axis is parallel to the line of sight so that the outflowing jet gas can be seen as blue shifted, variable absorption lines in the continuum of the underlying jet source. Based on our simulations we calculate and discuss synthetic absorption profiles. 
Based on a detailed comparison between model spectra and observations we discuss our hydrodynamical calculations for a pulsed jet in MWC 560 and suggest improvements for future models.