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Full-Text Articles in Physical Sciences and Mathematics
Testing The Wind-Shock Paradigm For B-Type Star X-Ray Production With Θ Carinae, Trisha F. Doyle
Testing The Wind-Shock Paradigm For B-Type Star X-Ray Production With Θ Carinae, Trisha F. Doyle
Theses and Dissertations
We present Chandra X-ray grating spectroscopy of the B0.2V star, θ Carinae. θ Car is in a critical transition region between the latest O-type and earliest B-type stars, where some of these stars are observed to have UV-determined mass-loss rates much lower than theoretically expected. In general, X-ray emission in this low-luminosity regime should be less prominent than in O-star winds, but observations have shown a higher than expected production of X-ray emission from the winds of these stars (e.g., Cohen et al. 2008; Huenemoerder et al. 2012). A hot wind could explain weak UV wind signatures, but this severely …
The Effects Of Thunderstorm Static And Quasi-Static Electric Fields On The Lower Ionosphere, Mohammad Ahmad Salem
The Effects Of Thunderstorm Static And Quasi-Static Electric Fields On The Lower Ionosphere, Mohammad Ahmad Salem
Theses and Dissertations
Thunderstorms and their lightning discharges are of great interest to many areas of geophysics and atmospheric electricity. A thunderstorm is an electric generator; it can produce both electrostatic and quasi-electrostatic fields in the overhead atmospheric D region. The D region is the lower part of the ionosphere that extends from about 40-90 km altitude where the electrons and ions are sufficient enough to affect the propagation of radio waves. In contrast to the electrostatic field, the quasi-electrostatic fields can be much stronger in magnitude, but shorter in duration, and can trigger halos. A halo is one type of the transient …