项目名称: 碘吸收盒定标技术改进的研究
项目编号: No.U1231118
项目类型: 联合基金项目
立项/批准年度: 2013
项目学科: 天文学、地球科学
项目作者: 王磊
作者单位: 中国科学院国家天文台南京天文光学技术研究所
项目金额: 50万元
中文摘要: 高精度视向速度测量是系外行星探索及星震学研究的强有力工具。目前使用的碘蒸汽盒定标技术是保证高精度视向速度测量的主要手段之一。该技术之所以可以获得1m/s的视向速度测量精度一方面是基于碘蒸气盒对光的吸收特性,另一方面是因为观测和定标共享同一光路,叠加在恒星光谱上的碘蒸气吸收线包含了仪器轮廓变化信息及seeing、导星的变化信息,利用这些信息可在数据处理时校正相应变化引起的波长漂移。此种碘吸收盒的运用模式,会带来效率损耗和光谱污染。本项目提出了一种新型的碘吸收盒定标运用模式,它既能保持碘蒸气盒的特有优势,又能消除碘蒸气的吸收损耗。该方法可以把视向速度测量精度提高20%~30%。 探索了一种新方法来改善seeing变化及导星偏差引起的光谱仪狭缝照明不稳定影响,与目前采用的方法相比避免了星光损耗,为今后激光频率梳技术运用中涉及的相关问题提供一个解决方案。
中文关键词: 天文仪器;光谱仪;光谱定标;波长定标;视向速度
英文摘要: A precise measurement of radial velocity of stars is a powerful technique in the search for extrasolar planets and for detecting solar-type oscillations. The iodine absorption cell calibration technique is one of the key tools to ensure achieving a high precision radial velocity measurement. This technology can obtain 1m / s radial velocity measurement precision is based on the I2 absorption lines are dense and narrow, and the observations and calibration that share the same optical path. The absorption lines that are superimposed on stellar spectrum contain the instrument profile change information and seeing, guiding change information. The information can be used for correcting wavelength shift caused by guiding and seeing changing in the data processing. The disadvantage of the application mode of iodine cell is the efficiency loss and spectral contamination. This project proposes a novel mode for iodine absorption cell application. It has maintained a unique advantage of the iodine vapor cell, and the elimination of iodine vapor absorption loss. The method can improve the radial velocity measurements with a precision of 20% ~ 30%. The project also explored a novel method used for reducing error of measuring caused by slit illumination changes. In contrast to the use of double optical fiber scrambler method,
英文关键词: Astronomical instruments;Spectrograph;Spectrum calibration;Wavelength calibration;Radial velocity