PROGRESS IN MEASUREMENTS OF THE GRAVITATIONAL BENDING OF RADIO WAVES USING THE VLBA
PROGRESS IN MEASUREMENTS OF THE GRAVITATIONAL BENDING OF RADIO WAVES USING THE VLBA
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DOI：
10.1088/0004-637x/699/2/1395
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发表时间：
2009-04
期刊：
影响因子：
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通讯作者：
E. Fomalont;Sergei M Kopeikin;G. Lanyi;J. Benson
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文献类型：
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作者：
E. Fomalont;Sergei M Kopeikin;G. Lanyi;J. Benson
2005年10月，我们利用43 GHz、23 GHz和15 GHz的甚长基线阵列（VLBA）在18天的时间里测量了四个射电源之间的太阳引力偏转。利用相位参考无线电干涉测量法将测量到的相位延迟拟合到参数化后牛顿形式的传播方程中，我们确定了偏转参数γ = 0.9998±0.0003（68%置信水平），与广义相对论一致。结果主要来自43千兆赫的观测，在那里，日冕的折射效应在距离太阳3度以上可以忽略不计。本实验的目的有三：改进以往太阳翼附近重力弯曲实验的结果；检查和评估地面VLBI技术的精度极限；并决定未来实验的前景和结果。我们的结论是，一系列改进设计的实验与VLBA可以提高精度至少4倍。
We have used the Very Long Baseline Array (VLBA) at 43, 23, and 15 GHz to measure the solar gravitational deflection of radio waves among four radio sources during an 18 day period in 2005 October. Using phase-referenced radio interferometry to fit the measured phase delay to the propagation equation of the parameterized post-Newtonian formalism, we have determined the deflection parameter γ = 0.9998 ± 0.0003 (68% confidence level), in agreement with general relativity. The results come mainly from 43 GHz observations where the refraction effects of the solar corona were negligible beyond 3 deg from the Sun. The purpose of this experiment is three-fold: to improve on the previous results in the gravitational bending experiments near the solar limb; to examine and evaluate the accuracy limits of terrestrial VLBI techniques; and to determine the prospects and outcomes of future experiments. Our conclusion is that a series of improved designed experiments with the VLBA could increase the presented accuracy by at least a factor of 4.