Disentangling Instrumental Features of the 130 GeV Fermi Line

Abstract

We study the instrumental features of photons from the peak observed at $E_{\gamma }=130$ GeV in the spectrum of Fermi-LAT data. We use the {\sc sPlots} algorithm to reconstruct -- seperately for the photons in the peak and for background photons -- the distributions of incident angles, the recorded time, features of the spacecraft position, the zenith angles, the conversion type and details of the energy and direction reconstruction. The presence of a striking feature or cluster in such a variable would suggest an instrumental cause for the peak. In the publically available data, we find several suggestive features which may inform further studies by instrumental experts, though the size of the signal sample is too small to draw statistically significant conclusions.

9 pages, 22 figures; this version includes additional variables, study of stat sensitivity, and modification to the chi-sq calculation

References in corpus (4)

• A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope
• Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre
• Strong Evidence for Gamma-ray Line Emission from the Inner Galaxy
• Two Lines or Not Two Lines? That is the Question of Gamma Ray Spectra

Cited by in corpus (3)

• Galactic Center Radio Constraints on Gamma-Ray Lines from Dark Matter Annihilation
• Re-Examining Astrophysical Constraints on the Dark Matter Model
• Indirect searches for dark matter with the Fermi LAT instrument