Observed photon spectrum of 1ES 0229+200. The solid lines are the linear regression results in the MeV-GeV and TeV energy bands. The Fermi-LAT observed data come from the second catalog (blue open circle) and third catalog (blue solid circle). The HESS observed data (black open circle) come from Aharonian et al. (2007) and VERITAS observed data (black solid circle) come from Aliu et al. (2014).