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'5-minute' solar oscillations observed in the continuum: Simultaneous three -wavelength photometric measurements with a ground-based instrument.

机译：连续观测到的“ 5分钟”太阳振荡：用地面仪器同时进行三波长光度测量。

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摘要

This dissertation reports on the first "5-minute" solar oscillation observations obtained with the Photometric Telescope, an instrument constructed in the Department of Physics at the University of Arizona. The instrument is designed to simultaneously acquire spatially resolved intensity images of the solar surface at three wavelengths in the solar continuum: 507 nm, 747 nm, and 1600 nm. Images were recorded at an approximate 30 second cadence, weather permitting, for an approximate 3 month duration during the Spring of 1999. A central rectangular region of the solar disk spanning +/-0.53 R⊙ in a direction parallel to the solar equator and +/-0.636 R⊙ in a direction parallel to the solar axis is used in obtaining the "5-minute" results.;Differential spatial filters utilizing the natural logarithm are developed. Proper design of these filters allows great reductions in the sensitivity to terrestrial atmospheric fluctuations as well as instrumental noise sources such as image fitter. The processing techniques utilized allow the simultaneous observation of solar oscillations in the 2500 to 3600 muHz region at each of the three instrumental wavelengths. The spatial filters used have high sensitivity to modes in the ℓ = 4 to ℓ = 8 range.;One-day power spectra from 40 long observing days are averaged. Concurrent data from the SOHO satellite's Luminosity Oscillation Imager is analyzed in a similar manner showing results in outstanding agreement with the Photometric Telescope spectra. Further comparison of measured power spectra peak locations with theoretically predicted peak locations verifies the Photometric Telescope as a capable helioseismology instrument.;New "5-minute" oscillation results are also presented. The amplitudes of the individual "5-minute" oscillations are on the order of 10--100 ppm, in agreement with previous amplitude measurements. While these amplitudes vary greatly depending on the details of the stochastic excitation, the oscillation amplitude ratios and phase differences of solar oscillations for the 507 nm, 747 nm, and 1600 nm wavelengths can be measured with a high degree of accuracy. This dissertation reports the first such measurements. The amplitude ratios (I'/I) 747/(I'/)507 ∼ 0.6 and (I'/I) 1600/(I'/I) 507) ∼ 0.25 are found to be independent of frequency over the frequency region studied and nearly independent of the angular degree of the mode. By contrast, the relative phase differences (&phis;747--&phis; 507) and (&phis;1600--&phis;507) are found to have a significant frequency dependence and to depend somewhat sensitively on the angular degree of the mode. The measured wavelength dependent amplitude and phase relationships provide an invaluable diagnostic tool which can be used in future work to help identify longer period and lower amplitude oscillatory modes.
机译：本论文报告了用光度望远镜获得的第一个“ 5分钟”太阳振荡观测结果，该仪器是由亚利桑那大学物理系建造的。该仪器旨在同时获取太阳连续区内三个波长的太阳表面空间分辨强度图像：507 nm，747 nm和1600 nm。在天气允许的情况下，以大约30秒的节奏记录图像，并在1999年春季进行了大约3个月的持续时间。太阳电池的中央矩形区域跨度为+/- 0.53 R＆odot。平行于太阳赤道和+/- 0.636 R＆odot的方向；沿平行于太阳轴的方向获得“ 5分钟”结果。开发了利用自然对数的微分空间滤波器。这些滤波器的正确设计可以大大降低对地面大气波动以及仪器噪声源（如图像拟合器）的敏感性。所使用的处理技术允许同时观察在三个仪器波长中的每个波长在2500至3600 muHz范围内的太阳振荡。使用的空间滤波器对＆ell;模式中的模式具有很高的灵敏度。 = 4至＆ell; = 8个范围。;对40个长期观察天的一日功率谱进行平均。来自SOHO卫星的“光度振荡成像器”的并行数据以类似的方式进行了分析，显示出与光度望远镜光谱具有显着一致性的结果。测得的功率谱峰值位置与理论上预测的峰值位置的进一步比较，证明了光度望远镜是一种功能强大的日震学仪器。还提出了新的“ 5分钟”振荡结果。各个“ 5分钟”振荡的振幅与以前的振幅测量结果相符，约为10--100 ppm。尽管这些振幅根据随机激励的细节而变化很大，但可以以高精度测量507 nm，747 nm和1600 nm波长的振荡振幅比和太阳振荡的相位差。本文首次报告了此类测量。发现振幅比（I'/ I）747 /（I'/）507〜0.6和（I'/ I）1600 /（I'/ I）507）〜0.25与所研究的频率范围内的频率无关并且几乎与模式的角度无关。相比之下，发现相对相位差（φ747-φ507）和（φ1600-φ507）具有明显的频率依赖性，并且在某种程度上敏感地取决于模式的角度程度。所测得的与波长有关的幅度和相位关系提供了一种宝贵的诊断工具，可用于将来的工作中，以帮助识别更长的周期和更低的振幅振荡模式。

著录项

  • 作者

    Womack, Gary Lynn.;

  • 作者单位

    The University of Arizona.;

  • 授予单位 The University of Arizona.;
  • 学科 Astronomy.
  • 学位 Ph.D.
  • 年度 2001
  • 页码 224 p.
  • 总页数 224
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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