PKS 1622-253: A weakly accreting, powerful gamma-ray source

Abstract

We discuss new deep radio observations of PKS 1622 - 253 and their implications for the energetics of the central engine that powers this strong high-energy gamma-ray source. Combining archival infrared and optical measurements with new millimeter observations, we show that even though the accretion flow in PKS 1622 - 253 is underluminous by quasar standards, a powerful superluminal jet is launched with a higher kinetic luminosity than most EGRET blazars. Only a few percent of the total jet kinetic luminosity is required to power even the most powerful gamma-ray flares that are observed. The implication is that a high-accretion system is not required in order to power the strongest high-energy gamma-ray sources.