Understanding the Physics and Dynamics of the NGC4839 Group as it Falls into the

We propose to complete our investigation of the massive group centered on the cDgalaxy NGC4839, which is falling into the Coma cluster. The completedobservations will allow the physics and dynamics of this merger to be studied inunprecedented detail. Our 112 ks (80 ks plus 40% overhead) XMMNewtonobservation was badly flared. To complete our program, we request an additional58 ks (which includes 40% overhead). With a complete data set, we will determinethe nature of the shock/sheath region at the interface between the Coma ICM andthe group gas, investigate the newly identified (120x75 kpc) cocoon surroundingNGC4839, and study the 400 kpc ram pressure stripped tail behind NGC4839 todetermine the importance of mixing of cluster gas with stripped group gas. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]