Raster Scanning the Crab Nebula to Produce an Extended VHE Calibration Source

TL;DR

This paper introduces a novel raster scanning technique on the Crab Nebula to create an artificial extended VHE gamma-ray source, aiding calibration and validation of analysis methods for gamma-ray observatories.

Contribution

It presents a new method of raster scanning the Crab Nebula to generate an artificial extended source for calibration purposes in VHE gamma-ray astronomy.

Findings

Successful implementation of raster scan technique

Generation of an extended calibration source

Initial results demonstrate viability of the method

Abstract

The Crab Nebula has long been the standard reference point source for very-high-energy (VHE, E $>$100 GeV) gamma-ray observatories such as VERITAS. It has enabled testing and improvement of analysis methods, validation of techniques, and has served as a calibration source. No comparable extended source is known with a high, constant flux and well understood morphology. In order to artificially generate such a source, VERITAS has performed raster scans across the Crab Nebula. By displacing the source within the field-of-view in a known pattern, it is possible to generate an extended calibration source for verification of extended source analysis techniques. The method as well as early results of this novel technique are presented.