2 research outputs found
GRB 050117: Simultaneous Gamma-ray and X-ray Observations with the Swift Satellite
The Swift Gamma-Ray Burst Explorer performed its first autonomous, X-ray
follow-up to a newly detected GRB on 2005 January 17, within 193 seconds of the
burst trigger by the Swift Burst Alert Telescope. While the burst was still in
progress, the X-ray Telescope obtained a position and an image for an
un-catalogued X-ray source; simultaneous with the gamma-ray observation. The
XRT observed flux during the prompt emission was 1.1 x 10^{-8} ergs cm^{-2}
s^{-1} in the 0.5-10 keV energy band. The emission in the X-ray band decreased
by three orders of magnitude within 700 seconds, following the prompt emission.
This is found to be consistent with the gamma-ray decay when extrapolated into
the XRT energy band. During the following 6.3 hours, the XRT observed the
afterglow in an automated sequence for an additional 947 seconds, until the
burst became fully obscured by the Earth limb. A faint, extremely slowly
decaying afterglow, alpha=-0.21. The X-ray position
triggered many follow-up observations: no optical afterglow could be confirmed,
although a candidate was identified 3 arcsecs from the XRT position.Comment: 27 pages, 6 figures. Accepted for publication in Ap
Proton- and Neutron-Induced SEU Cross-Section Modeling and Simulation: A Unified Analytical Approach
A new physics-based compact model, which makes it possible to simulate in a unified way the neutrons and protons of cosmic ray-induced SEU cross-sections, including the effects from nuclear reaction products and from direct ionization by low-energy protons, has been proposed and validated. The proposed approach is analytical and based on explicit analytical relationships and approximations with physics-based fitting parameters. GEANT4 or SRIM numerical calculations can be used as an aid to adjust or refine the phenomenological parameters or functions included in the model, taking into account real geometrical configurations and chemical compositions of the devices. In particular, explicit energy dependencies of the soft error cross-sections for protons and neutrons over a wide range of nucleon energies were obtained and validated. The main application areas of the developed model include space physics, accelerator studies high energy physics and nuclear experiments