DETECTION OF EXTENDED VHE GAMMA RAY EMISSION FROM G106.3+2.7 WITH VERITAS

We report the detection of very-high-energy (VHE) gamma-ray emission from supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission overlapping the elongated radio SNR. The 7.3σ (pre-trials) detection has a full angular extent of roughly 0.°6 by 0.°4. Most notably, the centroid of the VHE emission is centered near the peak of the coincident 12CO (J = 1–0) emission, 0.°4 away from the pulsar PSR J2229+6114, situated at the northern end of the SNR. Evidently the current-epoch particles from the pulsar wind nebula are not participating in the gamma-ray production. The VHE energy spectrum measured with VERITAS is well characterized by a power law dN/dE = N0(E/3 TeV)−Γ with a differential index of Γ = 2.29 ± 0.33stat ± 0.30sys and a flux of N0 = (1.15 ± 0.27stat ± 0.35sys) × 10−13 cm−2 s−1 TeV−1. The integral flux above 1 TeV corresponds to ∼5 percent of the steady Crab Nebula emission above the same energy. We describe the observations and analysis of the object and briefly discuss the implications of the detection in a multiwavelength context.