VERITAS Studies of the Supernova Remnants Cas A and IC 443

TL;DR

This paper reports on VERITAS observations of supernova remnants Cas A and IC 443, detecting TeV gamma rays and analyzing their morphology in relation to multiwavelength data.

Contribution

First TeV detections of Cas A and IC 443 by VERITAS, with analysis of their gamma-ray morphology and implications for cosmic-ray acceleration.

Findings

Strong TeV detections of Cas A and IC 443

Point-like TeV emission from Cas A

Extended TeV emission from IC 443

Abstract

VERITAS observed the supernova remnants Cassiopeia A (Cas A) and IC 443 during 2007, resulting in strong TeV detections of both sources. Cas A is a young remnant, and bright in both the radio and nonthermal X-rays, both tracers of cosmic-ray electrons. IC 443 is a middle-aged composite remnant interacting with a molecular cloud; the molecular cloud provides an enhanced density of target material for hadronic cosmic rays to produce TeV gamma rays via pion decay. The TeV morphology - point-like for Cas A and extended for IC 443 - will be discussed in the context of existing multiwavelength data on the remnants.