A late time look at the relativistic tidal disruption event Swift 2058+0516

In March and May this year, our collaboration discovered two examples of anapparently new class of high energy transient. Named Swift 1644+57 and Swift2058+0516, they are exceptionally Xray bright events, accompanied by emissionacross the electromagnetic spectrum. A working model is that these are the tidaldisruption of a star by the central black hole in a distant galaxy, althoughalternative models remain plausible. Here we seek long term observations ofSwift 2058+0516. Using XMMNewton we will measure both the lightcurve andspectrum at late times while the source is too faint for the SwiftXRT. In doingso we will determine late time properties of the object (e.g. disc vs jet) andcompare the lightcurve to the expectations for tidal disruption events. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]