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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:4
UID:UW-Physics-Event-7811
DTSTART:20221021T203000Z
DTEND:20221021T213000Z
DTSTAMP:20260414T152710Z
LAST-MODIFIED:20221021T185513Z
LOCATION:2241 Chamberlin Hall or online: https://uwmadison.zoom.us/j/8
 585501722
SUMMARY:Barschall Lecture: Shocking New Insights into Novae\, Physics 
 Department Colloquium\, Brian Metzger\, Columbia University & CCA Flat
 iron Institute
DESCRIPTION:"Novae" - thermonuclear outbursts from white dwarfs accret
 ing from a binary star companion - have been observed since antiquity 
 as "guest stars" to our ancestors.  Despite their storied place in the
  history of Astronomy\, our understanding of the physical processes th
 at give rise to novae and their emission remains strikingly incomplete
 .  Nothing illustrates this better than the unexpected discovery by NA
 SA's Fermi satellite that GeV gamma-ray emission is common if not ubiq
 uitous from novae.  These gamma-rays are likely produced by relativist
 ic ions accelerated at shock waves produced in the nova ejecta.  I wil
 l review our understanding of the multi-wavelength picture of novae\, 
 and describe how these transients can be used testbeds for studying re
 lativistic particle acceleration at non-relativistic shocks in the nov
 el "radiative" regime (in which the post-shock gas radiates ~100% of t
 he its thermal/non-thermal energy).  Lessons gleaned from novae can be
  applied to other shock-powered transients\, which are candidate high-
 energy neutrino sources for IceCube.  Time permitting\, I will describ
 e implications of the recent H.E.S.S. and MAGIC discovery of TeV gamma
 -rays from the recurrent nova RS Oph.
URL:https://www.physics.wisc.edu/events/?id=7811
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