Distinguishing Between Dark Matter and Pulsar Origins of the ATIC Electron Spectrum With Atmospheric Cherenkov Telescopes

TL;DR

This paper evaluates how atmospheric Cherenkov telescopes can distinguish whether a spectral feature in cosmic ray electrons is caused by dark matter or pulsars, offering a method to identify the origin with high confidence.

Contribution

It demonstrates that ground-based Cherenkov telescopes can effectively differentiate between dark matter and pulsar origins of the observed electron spectrum feature.

Findings

Cherenkov telescopes can resolve the spectral feature with >5 sigma significance.

The feature allows for calibration of telescope energy scales.

Discrimination between hypotheses is feasible even under conservative assumptions.

Abstract

Recent results from the Advanced Thin Ionization Calorimeter (ATIC) balloon experiment have identified the presence of a spectral feature between approximately 300 and 800 GeV in the cosmic ray electron spectrum. This spectral feature appears to imply the existence of a local (within about 1 kpc) source of high energy electrons. Emission from a local pulsar and dark matter annihilations have each been put forth as possible origins of this signal. In this letter, we consider the sensitivity of ground based atmospheric Cherenkov telescopes to electrons and show that observatories such as HESS and VERITAS should be able to resolve this feature with sufficient precision to discriminate between the dark matter and pulsar hypotheses with considerably greater than 5 sigma significance, even for conservative assumptions regarding their performance. In addition, this feature provides an opportunity to perform an absolute calibration of the energy scale of ground based, gamma ray telescopes.