A PRECESSING JET IN THE CH Cyg SYMBIOTIC SYSTEM

Abstract

Jets have been detected in only a few symbiotic binaries to date, and CH Cyg is one of them. In 2001, a non-relativistic jet was detected in CH Cyg for the first time in X-rays. We carried out coordinated Chandra, HST, and VLA observations in 2008 to study the propagation of this jet and its interaction with the circumbinary medium. We detected the jet with Chandra and HST and determined that the apex has expanded to the South from ∼300 AU to ∼1400 AU, with the shock front propagating with velocity <100 km s −1 . The shock front has significantly slowed down since 2001. Unexpectedly, we also discovered a powerful jet in the NE-SW direction, in the X-ray, optical and radio. This jet has a multi-component structure, including an inner jet and a counter-jet at ∼170 AU, and a SW component ending in several clumps extending out to ∼750 AU. The structure of the jet and the curvature of the outer portion of the SW jet suggest an episodically powered precessing jet, or a continuous precessing jet with occasional mass ejections or pulses. We carried out detailed spatial mapping of the X-ray emission and correlation with the optical and radio emission. Xray spectra were extracted of the central source, inner NE counter jet, and the brightest clump at a distance of ∼500 AU from the central source. We discuss the initial results of our analyses, including the multi-component spectral fitting of the jet-components and of the central source.

Discovery of a Giant, Highly Collimated Jet From Sanduleak's Star in the Large Magellanic Cloud

“…This behavior is known to occur across a wide class of stellar sources (Karovska et al 2010;Terquem et al 1999). Furthermore, the opposite curvature displayed by the SW lobe at its extremes leads us to speculate that the precessional period is comparable to-or shorter than-the travel time taken for the gas to flow over the 7 pc of the SW lobe.…”

SPHERE/ZIMPOL observations of the symbiotic system R Aquarii

“…Other well known examples are the precessing jets in CH Cyg, which resemble in many respects the R Aqr jets with radio emissions (e.g., Taylor et al 1986;Crocker et al 2002), Hα and [O III] line clouds, and X-ray hot spots (Corradi et al 2001;Karovska et al 2010). Other spectacular examples are Sanduleak's star in the Large Magellanic Clouds with a jet that extends over 14 pc (Angeloni et al 2011), or MWC 560, where the line of sight is parallel to the jet axis and the outflowing gas is seen in absorption in the continuum of the jet source (Tomov et al 1990;Schmid et al 2001).…”

Recent photometry of symbiotic stars

“…Leahy & Taylor 1987;Mukai et al 2009a), producing collimated outflows in the radio (e.g. Taylor et al 1986;Crocker et al 2001;Karovska et al 2007Karovska et al , 2010, because of a high orbital inclination (e.g. Skopal et al 1996).…”