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131.
X. Barcons 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1993,13(12):253-259
We review recent progress in the use of analyses of fluctuations in the cosmic X-ray background (XRB) to determine the source counts below the detection thresholds. Three flux domains are discussed: the range around 10−12erg cm−2 s−1 where the Ginga and Einstein Observatory results remain inconsistent unless the sources at these fluxes (mainly Seyfert galaxies) are highly absorbed at low energies, the 10−14erg cm−2 s−1 zone where the flattening of the source counts predicted by fluctuation analyses of Einstein Observatory images is now confirmed by Rosat, and the 10−15erg cm−2 s−1 flux domain, where fluctuation analyses of Rosat images show that source counts remain subeuclidean with very little contribution to the XRB coming from these sources. 相似文献
132.
X. J. Sun T. P. Li M. Wu L. X. Cheng 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1993,13(12):383-386
We report the detection of a soft X-ray component in the spectrum of the transient X-ray pulsar EXO2030+375 at a high state in 1985. The spectrum of the soft X-ray component could be fitted by a blackbody with a temperature kT 1.1 keV and a radius of the emission area R 3.6 – 6.1 km (assuming 5 kpc distance). 相似文献
133.
M. Amenomori X.J. Bi D. Chen S.W. Cui Danzengluobu L.K. Ding X.H. Ding C. Fan C.F. Feng Zhaoyang Feng Z.Y. Feng X.Y. Gao Q.X. Geng H.W. Guo H.H. He M. He K. Hibino N. Hotta Haibing Hu H.B. Hu J. Huang Q. Huang H.Y. Jia F. Kajino K. Kasahara Y. Katayose C. Kato K. Kawata Labaciren G.M. Le A.F. Li J.Y. Li Y.-Q. Lou H. Lu S.L. Lu X.R. Meng K. Mizutani J. Mu K. Munakata A. Nagai H. Nanjo M. Nishizawa M. Ohnishi I. Ohta H. Onuma T. Ouchi S. Ozawa J.R. Ren T. Saito T.Y. Saito 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
134.
Statistical study of electrostatic solitary waves associated with reconnection: Geotail observations
S.Y. Li X.H. Deng M. Zhou R.X. Tang K. Liu H. Kojima H. Matsumoto 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
The role of waves in the dynamics of the magnetotail has long been a topic of interest in magnetospheric physics. The characteristics of Electrostatic Solitary Waves (ESWs) associated with reconnection have been studied statistically in the magnetotail by surveying the large amounts data obtained from Waveform Capture (WFC) which is an important component of Plasma Wave Instrument (PWI) on the Geotail spacecraft. About 150 reconnection events with WFC data available are selected, and approximately 10 thousands of ESW waveforms are picked up by hands for statistical study. The ESWs are observed near diffusion region and near the plasma sheet boundary layer (PSBL). Two kinds of waveforms of ESWs are observed: bi-polar and tri-polar pulses. It is found that the pulse width of the ESWs is in the order of 1–5 ms and the peak-to-peak amplitude is in the order of 0.1–5 mV/m. The amplitudes of ESWs are larger in the near-earth tail region than that in deep tail region. ESWs have been observed with or without guide magnetic field 〈By〉. The characteristics of ESWs in different reconnection region and under different strength of guild magnetic field, their possible generation mechanism will be discussed. 相似文献
135.
E. Mitsakou G. Babasidis X. Moussas 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
We have used Omniweb data in order to identify the sheath and the ejecta boundaries of 67 shock-driving interplanetary coronal mass ejections during the time period 2003–2006. We examine and compare their statistical properties (speed, magnetic field strength, proton density and temperature, proton plasma beta), with those of the typical solar wind. We also calculate their passage time and radial width. We study the correlation between the ejecta and sheath characteristics. 相似文献
136.
X.-Q. Wang J. Cui X.-D. Wang J.-J. Liu H.-B. Zhang W. Zuo Y. Su W.-B. Wen H. Rème I. Dandouras C. Aoustin M. Wang X. Tan J. Shen F. Wang Q. Fu C.-L. Li Z.-Y. Ouyang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
In this paper, we present the first and preliminary results on the near-Moon plasma environment, based on the spectrogram data obtained with the Solar Wind Ion Detector (SWID) onboard Chang’E-2 from four lunar orbits on 10–11 Oct 2010. These orbits, at a constant altitude of ∼100 km, approach gradually the Lunar Magnetic Anomaly (LMA) at the Serenitatis antipode. The data reveal tentatively a region with decrement in proton density and enhancement in temperature. The near coincidence of this region with the Serenitatis antipode probably suggests the presence of a minimagnetosphere associated with the LMA, which effectively shields and heats the incident Solar Wind (SW) protons. 相似文献
137.
M. K. Reuss E. Keppler M. Fränz M. Witte N. Krupp B. Wilken A. Balogh R. J. Forsyth X. Moussas J. M. Polygiannakis A. D. Kakouris A. Alevizos 《Space Science Reviews》1995,72(1-2):343-346
In November 1992, the Ulysses spacecraft observed a multiple solar particle event and a CME event at 5.2 AU and a heliographic latitude of 20° S which were superimposed to the recurrent corotating interacting region. Distinct particle flux increases caused by these events were observed in all energy channels of the EPAC experiment. The experimental findings are discussed. 相似文献
138.
C. M. Jackman C. S. Arridge N. André F. Bagenal J. Birn M. P. Freeman X. Jia A. Kidder S. E. Milan A. Radioti J. A. Slavin M. F. Vogt M. Volwerk A. P. Walsh 《Space Science Reviews》2014,182(1-4):85-154
Spacecraft observations have established that all known planets with an internal magnetic field, as part of their interaction with the solar wind, possess well-developed magnetic tails, stretching vast distances on the nightside of the planets. In this review paper we focus on the magnetotails of Mercury, Earth, Jupiter and Saturn, four planets which possess well-developed tails and which have been visited by several spacecraft over the years. The fundamental physical processes of reconnection, convection, and charged particle acceleration are common to the magnetic tails of Mercury, Earth, Jupiter and Saturn. The great differences in solar wind conditions, planetary rotation rates, internal plasma sources, ionospheric properties, and physical dimensions from Mercury’s small magnetosphere to the giant magnetospheres of Jupiter and Saturn provide an outstanding opportunity to extend our understanding of the influence of such factors on basic processes. In this review article, we study the four planetary environments of Mercury, Earth, Jupiter and Saturn, comparing their common features and contrasting their unique dynamics. 相似文献
139.
Zhanlue Zhao Rong Li T.X. Jilkov V.P. 《IEEE transactions on aerospace and electronic systems》2004,40(4):1324-1336
In tracking applications, target dynamics are usually modeled in the Cartesian coordinates, while target measurements are directly available in the original sensor coordinates. Measurement conversion is widely used such that the Kalman filter can be applied in the Cartesian coordinates. A number of improved measurement-conversion techniques have been proposed recently. However, they have fundamental limitations, resulting in performance degradation, as pointed out in a recent survey conducted by the authors. A filter is proposed here that is theoretically optimal in the sense of minimizing the mean-square error among all linear unbiased filters in the Cartesian coordinates. The proposed filter is free of the fundamental limitations of the measurement-conversion approach. Results of an approximate, recursive implementation are compared with those obtained by two state-of-the-art conversion techniques. Simulation results are provided. 相似文献
140.
Interplanetary spacecraft navigation using pulsars 总被引:1,自引:0,他引:1
X.P. Deng G. Hobbs X.P. You M.T. Li M.J. Keith R.M. Shannon W. Coles R.N. Manchester J.H. Zheng X.Z. Yu D. Gao X. Wu D. Chen 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
We demonstrate how observations of pulsars can be used to help navigate a spacecraft travelling in the solar system. We make use of archival observations of millisecond pulsars from the Parkes radio telescope in order to demonstrate the effectiveness of the method and highlight issues, such as pulsar spin irregularities, which need to be accounted for. We show that observations of four millisecond pulsars every seven days using a realistic X-ray telescope on the spacecraft throughout a journey from Earth to Mars can lead to position determinations better than ∼20 km and velocity measurements with a precision of ∼0.1 ms−1. 相似文献