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E. M. Kellogg, J. Nichols (Harvard/Smithsonian CfA), J. Pedelty (NASA's GSFC), J. Sokoloski (Harvard/Smithsonian CfA)
Evidence for collimated outflows has been found in at least two classes of accreting white dwarfs -- symbiotic stars and supersoft x-ray sources. The symbiotic star R Aqr is the most dramatic example of a white dwarf collimated outflow, and it is also the first white dwarf with an x-ray jet. It was observed with both Chandra and the VLA in 2000, and then again with both instruments on 31 Dec 2003 and 7 Jan 2004, respectively. In 2000, the ~20 arcsec x-ray jet spectrum was consistent with a shock-heated plasma out of thermal equilibrium. In addition, the x-ray jet was somewhat larger than the radio jet. The more recent Chandra and VLA observations reveal several unexpected changes in the jets and central source at the R Aqr star position. The x-ray peak of the NE jet has apparently moved outward with an projected velocity of 600 km s-1, much higher than any previously measured in this system. The SW jet has moved out and faded significantly. There is evidence for further development of new jets close to the central binary star. The ACIS spectrum shows signs of evolution from collisional ionization towards thermal equilibrium in the NE jet. We also investigate the relevance of other newly observed sources of x-ray emission at angular separations of several arc min from the central star. We also compare the extended x-ray structure of R Aqr as observed with the ROSAT HRI in 1995 to the more recent observations. This work was supported by NASA under contract NAS8 39073 and grant GO4-5030A.
The author(s) of this abstract have provided an email address for comments about the abstract: emk@cfa.harvard.edu
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Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.