Simulating the Solar Shadow Allen I. MincerNYULANL 12/18/06

Stoermer Rule, as Modified by Henrici, adapted by AIM

Some More Calculation DetailsUsing Liouvilles theorem, isotropic C.R.s + B fields give isotropic C.R.s at Earth, unless absorbed, soGenerate backwards going C.R.s from Milagro to Sun or Moon. Shadow if Sun or Moon is hit.

New RunsBuilt in parametrization of MC of Milagro effective area and angular resolution from /data/links/G4MCData/Milagro/sets/20/proton/scattering_0.99_AbsL30m_ScatL50m/linkdirtrig/G4_proton_006769.trig.dat.gz1 year, take Sun/Moon position every 100 seconds.For each position, select energy from E-2.7 spectrum starting at 0.1 TeV.For each position generate 1.6K events centered on the vertices of a 40 x 40 grid 10 degrees around straight line to Sun/Moon : 0.1 degree steps in , cos.-> 5 x 108 particles tracked per run.Weight events by effective area.Run varying fields: B Earth only, B Earth + Sun dipole parallel to Earths dipole, B Earth + Sun dipole perp. to Earths dipole.Run with and without angular resolution

MC/Data Compare distribution Thanks Brian!

Moon Shadowed Particle energySun Shadowed Particle energyShadowed Particle Energy

Shadow with no B field/resolution

No B No Res, No Res, NoB, All

No B No Res, No Res, NoB, All

Sum over 1.2 degree radius bins

Sum over 1.2 degree radius bins

Sum over 1.2 degree radius binsSun Tot BSun Rot BMoon Tot B

Shadow Shape

Conclusions:Solar large scale shadow shape is overwhelmingly determined by Milagro resolution.Small scale (~1 degree) shape may have more sensitivity to B fieldShadow depth is determined to first order by whether particles strike sun. ie., strength of field. Next effect in MC is scattering out of 10 degrees.How sensitive to real differences? Next Step Look at data, then depending on how rich data statistics are:Build in realistic fields to test.Build in better Milagro resolution