In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope

Details In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope

2011-07-31

arxiv.org/abs/1108.0201v1

Astronomy and Astrophysics

Astrophysics

Instrumentation and Methods for Astrophysics

11 pages, 7 figures, submitted to Astroparticle Physics

Scientific paper

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between ~6 and ~13 GeV with an estimated uncertainty of ~2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

Affiliated with

Also associated with

No associations

Rating

In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-514290