Aspen, April 19, 2007Tom Gaisser1 10 17 eV decade Breakout summary.
-
date post
19-Dec-2015 -
Category
Documents
-
view
213 -
download
0
Transcript of Aspen, April 19, 2007Tom Gaisser1 10 17 eV decade Breakout summary.
Aspen, April 19, 2007 Tom Gaisser 3
Model dependence of composition in galactic-extragalactic transition
Allard, Olinto, Parizot, astro-ph/0703633
proton model mixed model
• Model extragalactic component• Subtract from observed to get galactic component
Aspen, April 19, 2007 Tom Gaisser 4
Berezhko & Völk
arXiv:0704.1715v1 [astro-ph]
• Model galactic component• Subtract from observed to get extragalactic
Transition predicted:
1016.5 to 1017.5 eV
Aspen, April 19, 2007 Tom Gaisser 5
Depth of Maximum
• Early transition favored– HiRes prototype
+ CASA/MIA– HiRes (E > 1018)
G. Archbold, P. Sokolsky, et al.,Proc. 28th ICRC, Tsukuba, 2003
HiRes new composition result: transition occurs before ankle
0.3 EeV
Aspen, April 19, 2007 Tom Gaisser 6
Composition from density of muonsρµ(600) vs. E0 (Akeno, AGASA)
From heavy
toward protons
Calculations by Bruce Dawson with MoccaSibyll
Aspen, April 19, 2007 Tom Gaisser 7
KASCADE-Grande : first analyses muon density investigations
KASCADE-Grandepreliminary
T. Pierog (EPOS)
MIA
Aspen, April 19, 2007 Tom Gaisser 9
Interaction models
• QGSjet01
• SIBYLL
• QGSjet02
• EPOS
Ralph Engel
Aspen, April 19, 2007 Tom Gaisser 14
Summary comments
• Two very different models of transition– 1017 to 1018 -or- 1018 to 1019 eV– Strong composition change signature– HiRes favors low-energy transition
• Model dependence a problem
• Good energy resolution important
• KASCADE-Grande, IceCube/IceTop, TALE, Amiga/HEAT at Auger