The exoplanet hunter HARPS: unequalled accuracy and perspectives toward 1 cm s-1 precision
The exoplanet hunter HARPS: unequalled accuracy and perspectives toward 1 cm s-1 precision
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DOI：
10.1117/12.669991
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发表时间：
2006-06
影响因子：
6.5
通讯作者：
C. Lovis;F. Pepe;F. Bouchy;G. Lo Curto;M. Mayor;L. Pasquini;D. Queloz;G. Rupprecht;S. Udry;S. Zucker
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文献类型：
--
作者：
C. Lovis;F. Pepe;F. Bouchy;G. Lo Curto;M. Mayor;L. Pasquini;D. Queloz;G. Rupprecht;S. Udry;S. Zucker
我们展示了安装在智利拉西拉天文台 ESO 3.6m 望远镜上的 HARPS 摄谱仪头两年的运行结果。该仪器主要用于探测太阳系外行星系统，其设计目的是实现有史以来最高的径向速度精度，这得益于高机械和环境稳定性、稳定的照明、精确的波长校准和仪器漂移跟踪。 HARPS 展示了 1 m s-1 及以下水平的长期精度，探索了 RV 精度的新机制。我们介绍了波长校准过程的最新改进，包括创建新的 ThAr 参考图集以及使用更多数量的线来拟合波长解决方案。我们还研究了 ThAr 校准灯的内在稳定性，并表明它们能够提供 1 m s-1 水平或以下的长期波长参考。讨论了其他仪器误差源，例如引导精度和光子噪声，并提出了全局误差预算。这些进一步提高 RV 精度的努力也是为 ESO OWL 望远镜建造超高精度分光测速仪（CODEX 项目）的更广泛研究的一部分。该仪器的目标是在至少十年的时间尺度内达到 1 cm s-1 的精度。这需要突破当今校准技术的限制，并探索能够提供超精确多普勒测量的新技术。
We present results from the first two years of operations of the HARPS spectrograph installed on the ESO 3.6m telescope at La Silla Observatory, Chile. This instrument, primarily built to detect extrasolar planetary systems, was designed to achieve the highest radial velocity precision ever, thanks to high mechanical and environmental stability, stable illumination, accurate wavelength calibration and tracking of instrumental drifts. HARPS has demonstrated a long-term accuracy at the 1 m s-1 level and below, exploring a new regime in RV precision. We present recent improvements in the wavelength calibration process, including the creation of a new ThAr reference atlas and the use of a much larger number of lines to fit the wavelength solution. We have also investigated the intrinsic stability of ThAr calibration lamps and show that they are able to provide a long-term wavelength reference at or below the 1 m s-1 level. Other instrumental error sources such as guiding accuracy and photon noise are discussed and a global error budget is presented. These efforts to further improve the RV precision are also part of a broader study to build a ultra-high accuracy spectrovelocimeter for the ESO OWL telescope, the CODEX project. The aim of this instrument is to reach an accuracy of 1 cm s-1 over timescales of at least ten years. This requires to push down the limits of present-day calibration techniques and to explore new technologies able to provide ultra-precise Doppler measurements.