Scott Wolk (Harvard-Smithsonian Center for Astrophysics) , C.M. Lisse (Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory), D. Bodewits (KVI atomic physics, University of Groningen), D.J. Christian (Queens University), K. Dennerl (Max-Planck-Institut für extraterrestrische Physik)
On May 23, 2006 we used the ACIS-S instrument on Chandra to study the X-ray emission from the B fragment of 0B: name SW3 changed into official nomenclature comet 73P/2006 (Schwassmann-Wachmann 3) (SW3-B). In 2006, Comet P/SW-3 had split into at least 43 tracked elements and countless additional pieces, as had passed closer to the Earth in May 2006 than any comet yet detected in X-rays. We obtained a total of 20 ks of observation time of Fragment B, and also obtained contemporaneous ACE and SOHO solar wind physical data. The Chandra data allow us to spatially resolve the detailed structure of the interaction zone between the solar wind and the coma at a resolution of 1,800 km, and to observed the X-ray emission due to multiple comet-like bodies. We fitted both charge exchange and free range spectral models to the whole comet and various regions. We detect a change in the spectral signature with increasing optical depth as predicted by Bodewits (2007). Further, we are able to understand the observed morphology in terms of non-gravitational forces, most notably solar radiation pressure acting on 
µ sized particles ejected from the fragment as it disintegrated. We have used the results of the Chandra observations on the highly fragmented SW3B debris field to re-analyze and interpret the mysterious emission seen from comet C/1999 S4 (Linear) on August 1st, 2000, after the comet had completely disrupted. We find the physical situations to be similar in both cases, with extended X-ray emission due to multiple, small out gassing bodies in the field of view. Nevertheless, the two comets interacted with completely different solar winds, resulting in distinctly different spectra.