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D. B. Melrose 《Space Science Reviews》1994,68(1-4):159-170
The theory of electron cyclotron maser emission and its application to solar spike bursts are reviewed. By analogy with the Earth's AKR, three sources of free energy are considered: a loss-cone anisotropy, a velocity-space hole, and a trapped distribution. The problem of how the radiation escapes through the second harmonic absorption layer is emphasized. Harmonic emission due to z mode coalescence may operate for some bursts, but the 2–5s delay between hard X-ray bursts and spike bursts suggests that some other mechanisms is required for most spike bursts. A model involving formation of a trapped distribution in low-density regions neighboring the flaring flux tube is considered. 相似文献
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M. Nakajima T. Mihara K. Makishima H. Niko 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2756-2758
We report on the luminosity dependent change of the cyclotron resonance energy obtained from a transient X-ray pulsar, 4U 0115+63. Using RXTE data observed on 1999 March, we found that the fundamental resonance energy stayed constant (11 keV) when the source luminosity was above 5 × 1037 erg s−1. As the luminosity decreased below 5 × 1037 erg s−1, the fundamental resonance energy gradually increased up to 16 keV at 0.16 × 1037 erg s−1. The luminosity dependence of the resonance energy can be understood by the change of the accretion column height. 相似文献
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W. Coburn P. Kretschmar I. Kreykenbohm V.A. McBride R.E. Rothschild R. Staubert J. Wilms 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2747-2751
The hard X-ray spectra of small subset of accreting pulsars show absorption-like line features in the range 10–100 keV. These lines, referred to as cyclotron lines or cyclotron resonance scattering features, are due to photons scattered out of the line of sight by electrons trapped in the 1012 G pulsar polar cap magnetic field. In this paper we present a review of observations, from the discovery of a cyclotron line in Hercules X-1 to recent results with RXTE and INTEGRAL. 相似文献
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