Operation of a broadband visible-wavelength astro-comb with a high-resolution astrophysical spectrograph
Operation of a broadband visible-wavelength astro-comb with a high-resolution astrophysical spectrograph
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带有高分辨率天体物理摄谱仪的宽带可见波长天文梳的操作
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
R. Walsworth
中科院分区：
文献类型：
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作者：
A. Glenday;Chih;N. Langellier;G. Chang;Li;G. Fűrész;A. Zibrov;F. Kärtner;D. Phillips;D. Sasselov;A. Szentgyorgyi;R. Walsworth
利用恒星吸收谱线的周期性多普勒频移来搜索类地系外行星，在以年为时间尺度的恒星径向速度（RV）测量中需要10厘米/秒的精度。目前的技术已经导致了短周期系外行星的发现，这些系外行星在其母恒星上引起RV的摆动小到约1米/秒。有人建议，使用天文梳可以实现数量级的RV精度提高，天文梳是一种用于天体物理光谱仪波长校准的激光频率梳。在这里，我们报告了宽带可见波长天文梳的发展及其在加那利群岛伽利略国家望远镜的HARPS-N光谱仪上的运行。这颗绿色的天文梳状体有7000条窄窄的（<1兆赫）谱线，间隔为16千兆赫，谱线功率在500到620纳米之间相对均匀。线路频率锁定到GPS，使我们能够实现HARPS-N波长校准，RV测量精度和稳定性<10 cm/s。
Searches for Earth-like exoplanets using the periodic Doppler shift of stellar absorption lines require 10 cm/s precision in the measurement of stellar radial velocity (RV) over timescales of years. Current techniques have led to the discovery of short-period exoplanets that induce RV wobbles as small as ≈1 m/s on their parent stars. It has been suggested that order-of-magnitude improved RV precision may be achievable using an astro-comb, a laser frequency comb optimized for astrophysical spectrograph wavelength calibration. Here we report the development of a broadband visible-wavelength astro-comb and its operation with the HARPS-N spectrograph at the Telescopio Nazionale Galileo in the Canary Islands. This green astro-comb has >7000 narrow (<1 MHz) spectral lines spaced by 16 GHz with relatively uniform line power from 500 to 620 nm. The line frequencies are locked to GPS, enabling us to realize HARPS-N wavelength calibration with RV measurement precision and stability <10 cm/s.