On Synchrotron Radiation from Messier 87.

The recent discovery by Baade that the optical radiation emitted by the jet in M87 is strongly polarized-and thus is synchrotron radiation-is a confirmation of a prediction made by Shklovsky and others. In this paper calculations of the required conditions of magnetic-field and particle energies are made, for both the optical and the radio emission. To account for the optical radiation in the jet, the total energy required in particles and field ranges from about 10 to 10 ergs for a series of assumed magnetic fields ranging from 10- to 10-6 gauss. To account for the radio emission for the same series of magnetic- field strengths, total energies in the range ergs are demanded. It is suggested that reasonable values are about 2 X 10 ergs in particles and field, with H 10- gauss, in the jet and about 10 ergs in a volume 200 times greater than that of the jet, also with H 10- gauss, which will explain the radio emission. By considering nuclear collisions of the high-energy protons with the static material present in the jet, it is shown that a continuous supply of electrons and positrons will be produced. If a density of about 3 X 10- gm/cc is assumed in the jet, the rate of electron-positron energy generation will be sufficient to balance the loss of energy by synchrotron radiation. The jet will also be a source of highenergy gamma radiation. Energy sources which might give rise to the primary particles and magnetic fields are discussed. It is suggested that the presence of antimatter in M87 would lead to a very powerful source of high-energy electrons and positrons.