Background Systematic Studies in VERITAS Data

TL;DR

This paper investigates why background significance distributions in VERITAS data often have greater width than expected, identifies causes, and proposes solutions to improve background estimation accuracy in gamma-ray astronomy.

Contribution

It analyzes the origins of wide significance distributions in VERITAS data and develops methods to correct background estimation issues.

Findings

Identified causes of wide significance distributions in VERITAS data

Developed solutions to improve background estimation accuracy

Tested solutions successfully on VERITAS data samples

Abstract

In the analysis of VERITAS and other IACT data, it is expected to get a distribution of statistical significances in sky map bins with mean of zero and width of unity in the absence of a $\gamma$-ray signal. However, it is not uncommon to see significance distributions of width greater than unity, indicating that the background is poorly estimated and the significances in the region of interest are incorrect. This work explores the origins of these wider significance distributions and develop solutions to this issue and test these solutions on samples of VERITAS data.