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Brainerd, J. J.

Publications and source records attributed to Brainerd, J. J..

21 records · Page 2

Synchrotron emission and gamma-ray bursts

The parameter space within which synchrotron emission models for gamma-ray burst spectra are valid is evaluated in the cases of thermal and power-law particle distributions. The spectra emitted by noncooling and cooling thermal and power-law particle distributions are modeled numerically over relativistic and nonrelativistic regimes. The structure of the radiation is defined near the fundamental and the continuum up to the 1000th harmonic. Comparisons are made with burst event data collected during the Apollo 16, Venera, SMM, Pioneer Venus Orbiter and Hackucho missions. A two-component synchrotron model is proposed for gamma-ray burst events. The electron-positron distribution is projected to have a thermal component and a nonthermal power-law tail.

Brainerd, J. J.↗

Orientations of AM Her stars from their polarization properties - The case of the missing AM Her stars

Observation of the polarization properties of the AM Her stars is used to determine their orientations. It is found that the AM Her stars are randomly distributed with respect to their inclination angle i but not with respect to their magnetic colatitude delta. The stars are concentrated along the semicircle cos-squared delta + cos-squared i = 1, where delta is the angle between the magnetic moment and the spin axis of the degenerate dwarf. This result implies that the discovery of AM Her stars is strongly affected by observational selection effects. It is suggested that these effects are a result of the way in which the AM Her stars have been identified observationally, and of the angular properties of high harmonic cyclotron emission. It is estimated that there are about three times as many AM Her stars as have been found so far.

Brainerd, J. J.↗

Analysis of thermal environment in the thrustor cavity of space vehicles

Wind tunnel tests to determine the mechanisms involved in producing the high local heating rates in and around the thrustor nozzle in a non-firing condition are reported. The geometry of a typical nozzle installation is described. Procedures for reducing the effects of hypersonic flow interactions in order to prevent excess local heating are explained.

Chiou, J. N.↗