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Xing Li

Publications and source records attributed to Xing Li.

128 records · Page 8Linked to original sources

C++ Codes of Implicit Lu Algorithms for Absdll01

This report is devoted to some C++ codes implementing the implicit LU class algorithms for solving linear determined, and undetermined systems with $n$ variables and $m$ equations. A main program used in part of the numerical test is given in the last section.

math.NA↗

The effect of temperature anisotropy on observations of Doppler dimming and pumping in the inner corona

Recent observations of the spectral line profiles and intensity ratio of the O VI 1032 Å and 1037.6 Å doublet by the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO), made in coronal holes below 3.5 $R_s$, provide evidence for Doppler dimming of the O VI 1037.6 Å line and pumping by the chromospheric C II 1037.0182 Å line. Evidence for a significant kinetic temperature anisotropy of O$^{5+}$ ions was also derived from these observations. We show in this Letter how the component of the kinetic temperature in the direction perpendicular to the magnetic field, for both isotropic and anisotropic temperature distributions, affects both the amount of Doppler dimming and pumping. Taking this component into account, we further show that the observation that the O VI doublet intensity ratio is less than unity can be accounted for only if pumping by C II 1036.3367 Å in addition to C II 1037.0182 Å is in effect. The inclusion of the C II 1036.3367 Å pumping implies that the speed of the O$^{5+}$ ions can reach 400 km/s around 3 $R_s$ which is significantly higher than the reported UVCS values for atomic hydrogen in polar coronal holes. These results imply that oxygen ions flow much faster than protons at that heliocentric distance.

astro-ph↗