We report the detection of very high energy 7-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae (z=p 0.102) by VERITAS. The source was observed between 2008 January and April. A strong outburst of 7-ray emission was measured in the middle of March, lasting for only 4 days. The energy spectrum measured during the two highest flare nights is fit by a power law and is found to be very steep, with a differential photon spectral index of ×=3.81 ± 0.35stat ± 0.34syst. The integral photon flux above 200 GeV during those two nights corresponds to roughly 9% of the flux from the Crab Nebula. Quasi-simultaneous Swift observations at X-ray energies were triggered by the VERITAS observations. The spectral energy distribution of the flare data can be described by synchrotron self-Compton (SSC) or external Compton (EC) leptonic jet models.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science