Scientific Colloquium
May 18, 2012


"Swift J164449.3+573451: Death Throes of an Unlucky Star"

On 28 March 2011 Swift was triggered by a slowly rising hard X-ray source that was initially misidentified as a GRB, but was later interpreted as a beamed tidal disruption event (TDE) in a distant galaxy.  This is the first time that a TDE triggered a transient monitor, and the Swift detection of this object resulted in an intensive multiwavelength campaign.  The interpretation that the TDE launched a relativistic jet also was a wrinkle on previous theoretical discussions of tidal disruption events, which concentrated on optical/UV and X-ray flares from the star, the accretion disk, and the ejected wind, all of which are orders of magnitude less luminous than the beamed emission from this object.  Swift has observed this object for over a year, and the X-ray flux is decaying as expected for the TDE interpretation, albeit with large variations (+/- factors of 3).  I will discuss this event, how it differs from GRBs, and what we have learned from it.

Return to Schedule