日震数据的有效拟全局拟合
Efficient pseudo-global fitting for helioseismic data
摘要：
模式拟合或“峰值装袋”是日震学中的一个重要步骤，可以用来确定太阳振荡的各种模式参数。在这里，我们描述了一种减少某些模式参数拟合中系统偏差的方法，这些参数是在使用“局部”拟合技术分析太阳作为恒星的p模式功率谱时看到的。为此，我们开发了一种新的“伪全局”拟合算法，旨在获得拟合整个功率谱的优势，但没有拟合包含数百个参数的模型所涉及的问题。通过拟合模拟日震数据的“极限”剖面，我们对局部和伪全局峰值装袋技术进行了比较分析。结果表明，对于非对称模态，传统的拟合技术返回的中心频率参数的系统有偏估计。当采用伪全局例程时，这种偏差显著减小。类似地，我们表明，从伪全局例程返回的背景的估计值比从局部拟合方法返回的估计值更接近地匹配输入值。我们还使用这两种拟合技术来分析欧空局/美国航天局太阳和日光层天文台（SOHO）航天器上的全球低频振荡（GOLF）仪器收集的一组真实的太阳数据。当拟合真实和模拟数据时，可以看到两种技术返回的估计频率之间的类似差异。我们发现，背景拟合返回的伪全球例程更紧密地匹配背景的估计，可以推断从拟合之间的插值的p-模式功率谱的高，低频率端。
英文摘要：
Mode fitting or "peak-bagging" is an important procedure in helioseismology allowing one to determine the various mode parameters of solar oscillations. Here we describe a way of reducing the systematic bias in the fits of certain mode parameters that are seen when using "local" fitting techniques to analyse the sun-as-a-star p-mode power spectrum. To do this we have developed a new "pseudo-global" fitting algorithm designed to gain the advantages of fitting the entire power spectrum, but without the problems involved in fitting a model incorporating many hundreds of parameters. We have performed a comparative analysis between the local and pseudo-global peak-bagging techniques by fitting the "limit" profiles of simulated helioseismic data. Results show that for asymmetric modes the traditional fitting technique returns systematically biased estimates of the central frequency parameter. This bias is significantly reduced when employing the pseudo-global routine. Similarly, we show that estimates of the background returned from the pseudo-global routine match the input values much more closely than the estimates from the local fitting method. We have also used the two fitting techniques to analyse a set of real solar data collected by the Global Oscillations at Low Frequencies (GOLF) instrument on board the ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Similar differences between the estimated frequencies returned by the two techniques are seen when fitting both the real and simulated data. We show that the background fits returned by the pseudo-global routine more closely match the estimate of the background one can infer from interpolating between fits to the high and low frequency ends of the p-mode power spectrum.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
