Stephen K N PORTILLO, Harvard Universitywith Douglas P FINKBEINER26 June 2014Astroparticle Physics (TeVPA/IDM), Amsterdam
Sharper Fermi-LAT Images
Portillo & Finkbeiner, 1406.0507submitted to ApJ
Signal Region
Galactic Plane Leakage
Angular Resolution Matters
Galactic Plane (bright and hard to model!)
Point Spread Function
tungstensilicon
Multiple Coulomb scatteringin tungsten foils (low E)
Limited silicon stripposition resolution (high E)
Conversion insupport material
Hard scatteringMissed silicon hit
Track confusion
Idea
l Eve
ntUni
deal
Eve
nt
FRONT BACK
[TRANSIENT]
SOURCE
CLEAN
ULTRACLEAN
Event Classes + CTBCORE
Q2
Q1
Dividing the front-converting events…
Pulsars as Point Sources
- =
On-phase Off-phase Pulsar
(Bill Saxton, NRAO)
PSF Fitting ULTRACLEAN: Allfront, Q2, Q1
Effective Area
Surviving Fraction, CLEAN, Q2
×
Effective Area, CLEAN (m2)
(Fermi Science Support Centre)
1
0.22.5 4𝐥𝐨𝐠𝟏𝟎 (𝑬 /MeV )
𝐜𝐨𝐬𝜽
0.5
0
Effective Area Error Estimate
±0.01
0.3-0.5 GeV, CLEAN, Allfront
0.3-0.5 GeV, CLEAN, Q2
0.3-0.5 GeV, CLEAN, Allfront minus Q2
Before CTBCORE cut
After CTBCORE cutBefore CTBCORE
After CTBCORE
Daylan et al. (2014), arXiv
Conclusion
Galactic Plane Leakage
Galactic Plane- =
1
0.22.5 4𝐥𝐨𝐠𝟏𝟎 (𝑬 /MeV )
𝐜𝐨𝐬𝜽
0.5
0
Effective Area
Signal Region
Idea
l Eve
nt
Point-Spread Function
Check out the maps + IRFs at
http://fermi.skymaps.info/