Latest view of CTA 1 with VERITAS

Abstract

CTA 1 is a shell-type supernova remnant (SNR) with a central pulsar wind nebula (PWN), visible at very-high-energy (VHE) from 50 GeV to 100 TeV from a moderately extended emission region. While general consensus concludes the VHE emission originates from relativistic leptons accelerated by the PWN and undergoing inverse Compton scattering, questions remain about electron escape and propagation, as well as the evolutionary stage of this particular PWN. CTA 1 is on the cusp of middle age (~13 kyr) and spatially resolvable at energies visible to imaging atmospheric Cherenkov telescopes (IACTs), such as the Very Energetic Radiation Imaging Telescope Array System (VERITAS) (PSF < 0.1 deg). Therefore, this remnant is an excellent candidate to study lepton propagation and escape between different PWN evolutionary stages. Since the initial VERITAS publication on CTA 1 in 2013, VERITAS has performed new observations, adding to a total exposure of about 120 hours. We have analyzed the entire VERITAS CTA 1 dataset to date and report results.