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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:4
UID:UW-Physics-Event-7975
DTSTART:20221028T190000Z
DTEND:20221028T200000Z
DTSTAMP:20260414T153723Z
LAST-MODIFIED:20221020T133538Z
LOCATION:CH 4274
SUMMARY:Powerful Indirect Constraints on the Origins of Ultra High Ene
 rgy Cosmic Rays \, NPAC (Nuclear/Particle/Astro/Cosmo) Forum\, Glennys
  Farrar\, NYU
DESCRIPTION:As is now painfully evident\, finding the sources of UHECR
 s is very challenging due to the combination of most UHECRs having int
 ermediate masses\, the poor precision in individual UHECR charge assig
 nments\, and generally large deflections in the imperfectly-known Gala
 ctic magnetic field.   These effects not only smear the images of indi
 vidual UHECR sources but also lead to a non-trivial and poorly-constra
 ined mapping between a source's direction and the arrival direction di
 stribution of its UHECRs. In the face of this challenge\, indirect inf
 ormation on the sources which is imprinted on the spectrum and composi
 tion of UHECRs as they emerge from the source surroundings and on the 
 neutrinos they produce\, provides valuable additional information on t
 he nature of the sources. This talk will discuss the resulting constra
 ints on the physical properties of the environment surrounding the sou
 rce\, and a possible picture that emerges when also considering eviden
 ce on the number density and diversity of source types.  
URL:https://www.physics.wisc.edu/events/?id=7975
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