HIGH-ENERGY PARTICLES FROM ACTIVE GALACTIC NUCLEI

In this paper, I summarize the results of recent work by myself and co lleagues on the production of high energy neutrinos, gamma-rays and co smic rays in radio-quiet active galactic nuclei (AGN) or in the centra l regions of radio-loud AGN. In this work, we used a model in which ac celeration of protons takes place at a shock in an accretion flow onto a supermassive black hole, and follow the cascade that results from i nteractions of the accelerated protons in the AGN environment. Our res ults are used to estimate the diffuse high energy neutrino, gamma-ray and cosmic ray intensity due to AGN. I discuss our results in the cont ext of existing data and future experiments. Finally, I describe a new self-consistent calculation by Mastichiadis and Kirk.