Discovery of Very-High-Energy Emission from RGB J2243+203 and Derivation of Its Redshift Upper Limit
A. U. Abeysekara et al 2017 ApJS 233 7
Gamma-ray emission at >100 GeV was discovered from the blazar RGB J2243+203 with the VERITAS Cherenkov telescope array, allowing for upper limits of z < 0.9 to z < 1.1 to be set on its redshift.