Extending the Galactic Cosmic Ray Electron + Positron Spectrum Measured by the Fermi Large Area Telescope
Abstract
The Fermi observatory was launched on the 11th of June into a nearly circular orbit with an inclination of 25.6 degrees and an altitude of 565 km. After the first six months of operation, the Fermi Large Area Telescope was able to measure the high statistics Galactic Cosmic Ray electron + positron (GCRE) spectrum from 20 GeV to 1 TeV. Given the orbit in which the observatory is in, it is possible to measure the GCREs down to 6 GeV. However, this lower limit is tied to the rigidity cutoff and is therefore a function of the geomagnetic coordinate, McIlwain L. In order to successfully measure the spectrum down to these energies it is necessary to sample the population of electrons + positrons detected while the LAT is in several different McIlwain L regions. In this poster we present the details of the analysis used to extend the GCRE spectrum measured by the Fermi LAT.
- Publication:
-
AAS/High Energy Astrophysics Division #11
- Pub Date:
- March 2010
- Bibcode:
- 2010HEAD...11.3601P