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Possible gamma-ray emission of radio intermediate AGN III Zw 2 and its implication on the evolution of jets in AGNs

AGNs with hard $γ$-ray emission identified so far are radio-loud. III Zw 2 is a radio intermediate AGN with a relativistic jet. We study its spectral energy distribution (SED) and find that the broad band emissions are dominated by the non-thermal emissions from the jet. We model its SED through a synchrotron + inverse Compton (IC) model. The results show that the IC component of III Zw 2 peaks at a few MeV, and the flux density drops rapidly at higher energy with photon index $Γ\approx3.3$ above 0.1 GeV. The predicted flux is slightly over the sensitivity of $Fermi$/LAT, but it is not included in the first $Fermi$/LAT AGN catalog. The reason for this may be: 1) that the IC peak is low and the spectrum is very steep above 0.1 GeV, 2) that III Zw 2 is in the low state during the period of the $Fermi$/LAT operation. We also find that III Zw 2 follows similar jet processes as those in $γ$-ray AGNs, e.g., the relation between jet power and radiation power, called the blazar sequence. We suggest that III Zw 2 may be a young source at an earlier stage of jet activity.