Spectrum, angular distribution and polarization of auroral hard X-rays

Khosa, P. N.; Rausaria, R. R.; Moza, K. L.

doi:10.1016/0032-0633(84)90039-4

Cited by 4 publications

(3 citation statements)

References 22 publications

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“…Several models using dierent approximations and simpli®cations have been developed in order to calculate the yield of X-rays from electron spectra (Rees, 1964;Kamiyama, 1966;Freyer, 1969;Berger et al, 1970;Berger and Seltzer, 1972;Seltzer and Berger, 1974;Luhman and Blake, 1977;Walt et al, 1979;Khosa et al, 1984;Robinson et al, 1989;Gorney, 1987). Experiments have been performed to make simultaneous measurements of electrons and X-rays (Vij et al, 1975;Mizera et al, 1978;Goldberg et al, 1982;Datlowe et al, 1988), and the comparisons between measured and calculated X-rays have resulted in dierent degrees of agreement.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous measurements of X-rays and electrons during a pulsating aurora

et al. 1998

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Abstract. The PULSAUR II rocket was launched from Andùya Rocket Range at 23.43 UT on 9 February 1994 into a pulsating aurora. In this paper we focus on the observations of precipitating electrons and auroral X-rays. By using models it is possible to deduce the electron energy spectrum from X-ray measurements. Comparisons are made between the deduced electron uxes and the directly measured electron¯uxes on the rocket. We found the shape of the observed and the deduced electron spectra to ®t very well, with almost identical e-folding energies in the energy range from 10 ke V to $ 60±80 ke V. For the integrated¯uxes from 10.8 to 250 ke V, we found a discrepancy of 30% . By combining two models, we have found a good method of deducing the electron precipitation from X-ray measurements. The discrepancies between calculations and measurements are in the range of the uncertainties in the measurements.

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Section: Introductionmentioning

confidence: 99%

Simultaneous measurements of X-rays and electrons during a pulsating aurora

et al. 1998

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“…As balloon and rocket experiments have recorded auroral X-rays since about 1960, there has been a need for models that calculate the X-ray production from electron precipitation. Several models using dierent approximations and simpli®cations have been developed in order to calculate the yield of X-rays from electron spectra (Rees, 1964;Kamiyama, 1966;Freyer, 1969;Berger et al, 1970;Berger and Seltzer, 1972;Seltzer and Berger, 1974;Luhman and Blake, 1977;Walt et al, 1979;Khosa et al, 1984;Robinson et al, 1989;Gorney, 1987). Experiments have been performed to make simultaneous measurements of electrons and X-rays (Vij et al, 1975;Mizera et al, 1978;Goldberg et al, 1982;Datlowe et al, 1988), and the comparisons between measured and calculated X-rays have resulted in dierent degrees of agreement.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous measurements of X-rays and electrons during a pulsating aurora

et al. 1998

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Abstract. The PULSAUR II rocket was launched from Andøya Rocket Range at 23.43 UT on 9 February 1994 into a pulsating aurora. In this paper we focus on the observations of precipitating electrons and auroral X-rays. By using models it is possible to deduce the electron energy spectrum from X-ray measurements. Comparisons are made between the deduced electron fluxes and the directly measured electron fluxes on the rocket. We found the shape of the observed and the deduced electron spectra to fit very well, with almost identical e-folding energies in the energy range from 10 ke V to ~60–80 ke V. For the integrated fluxes from 10.8 to 250 ke V, we found a discrepancy of 30% . By combining two models, we have found a good method of deducing the electron precipitation from X-ray measurements. The discrepancies between calculations and measurements are in the range of the uncertainties in the measurements.Key words. Ionospheric particle precipitation · Magnetospheric physics · Annual phenomena · Energetic particle

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“…Together with a line or a band of emissions that is proportional to the total electron energy flux, a two-parameter electron distribution can be derived. Such a technique was used by Germany et al [1997, 1998a, 1998b] As the production of X-ray bremsstrahlung is fairly well understood, the X-ray production from electron precipitation can be estimated and several aleconvolution techniques has been developed over the last decades [Rees, 1964;Kamiyama, 1966;Berger et al, 1970;Berger and Seltzer, 1972;Seltzer and Berger, 1974;Luhmann and Blake, 1977;Walt et al, 1979;Khosa et al, 1984;Robinson et al, 1989;Gorney, 1987;Lorence, 1992]. Anderson et al [1998] and Ostgaard et al [2000] utilized such techniques and showed that the X-ray measurements by the Polar Ionospheric X-ray Imaging Experiment (PIXIE) [Imhof et al, 1995] out the text we will refer to these boxes as •700-km boxes, although their size varies with latitude.…”

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confidence: 99%

Auroral electron distributions derived from combined UV and X‐ray emissions

Østgaard¹,

Stadsnes²,

Bjordal³

et al. 2001

J. Geophys. Res.

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Abstract. The Polar Ionospheric X-ray Imaging Experiment and the Ultraviolet Imager on board the Polar satellite provide the first simultaneous global scale views of the electron precipitation over a wide range of electron energies. By combining the results from these two remote sensing techniques we have developed a method to derive the electron energy distributions that reproduce the true electron spectra from I to 100 keV and that can be used to calculate the energy flux in the energy range from 100 eV to 100 keV. The electron energy spectra obtained by remote sensing techniques in three 5-min time intervals on July 9 and July 31, 1997, are compared with the spectra measured by low-altitude satellites in the conjugate hemisphere. In the energy range from 90 eV to 30 keV the derived energy flux is found to be 1.034-0.6 of the measured energy fluxes. The method enables us to present 5-min time-averaged global maps of precipitating electron energy fluxes with a spatial resolution of •700 km. The study shows that the combination of UV and X-ray cameras on a polar orbiting spacecraft enables comprehensive monitoring of the global energy deposition from precipitating electrons over the energy range that is most important for magnetosphere-ionosphere coupling.

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Spectrum, angular distribution and polarization of auroral hard X-rays

Cited by 4 publications

References 22 publications

Simultaneous measurements of X-rays and electrons during a pulsating aurora

Simultaneous measurements of X-rays and electrons during a pulsating aurora

Simultaneous measurements of X-rays and electrons during a pulsating aurora

Auroral electron distributions derived from combined UV and X‐ray emissions

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