Synchrotron radiation

About: Synchrotron radiation is a research topic. Over the lifetime, 14639 publications have been published within this topic receiving 244775 citations. The topic is also known as: magnetobremsstrahlung radiation & Synchrotron Radiation.

Nuclear resonance excitation by synchrotron radiation

Abstract: We have excited the 14-keV level of the Fe/sup 57/ nucleus using synchroton radiation, and observed the conversion electrons emitted in the decay of that state. We believe this to be the first observation of nuclear excitation via synchrotron-produced x rays.

A compact pulsar wind nebula model of the γ-ray-loud binary LS I +61○303

Abstract: We study a model of LS I +61°303 in which its radio to TeV emission is due to interaction of a relativistic wind from a young pulsar with the wind from its companion Be star. The detailed structure of the stellar wind plays a critical role in explaining the properties of the system. We assume the fast polar wind is clumpy, which is typical for radiatively driven winds. The clumpiness and some plasma instabilities cause the two winds to mix. The relativistic electrons from the pulsar wind are retained in the moving clumps by inhomogeneities of the magnetic field, which explains the X-ray variability observed on time-scales much shorter than the orbital period. We calculate detailed inhomogeneous spectral models reproducing the average broad-band spectrum from radio to TeV Given the uncertainties on the magnetic field within the wind and the form of the distribution of relativistic electrons, the X-ray spectrum could be dominated by either Compton or synchrotron emission. The recent Fermi observations constrain the high-energy cut-off in the electron distribution to be at the Lorentz factor of 2 x 10 4 or ∼ 10 8 in the former and latter model, respectively. We provide formulae comparing the losses of the relativistic electrons due to Compton, synchrotron and Coulomb processes versus the distance from the Be star. We calculate the optical depth of the wind to free-free absorption, showing that it will suppress most of the radio emission within the orbit, including the pulsed signal of the rotating neutron star. We point out the importance of Compton and Coulomb heating of the stellar wind within and around the y -ray emitting region. Then, we find the most likely mechanism explaining the orbital modulation at TeV energies is anisotropy of emission, with relativistic electrons accelerated along the surface of equal ram pressure of the two winds. Pair absorption of the TeV emission suppresses one of the two maxima expected in an orbit.

Preferential positron heating and acceleration by synchrotron maser instabilities in relativistic positron--electron--proton plasmas

Abstract: A new process of the preferential strong heating of positrons through the ion synchrotron maser instability in positron-electron-proton magnetized plasmas is investigated using particle-in-cell simulations. It is shown that the positrons form a nonthermal power-law-like energy distribution via their gyroresonant interaction with the extraordinary modes emitted by the ions. It is noted that this process may be of significance in connection with the shock excitation of nonthermal synchrotron radiation from astrophysical systems powered by relativistic outflows from compact central objects, e.g., supernova remnants powered by pulsars and jets from active galactic nuclei.