Collaborative Research: Development of a Green-Orange Astro-comb for Exoplanet and Cosmology Research

合作研究：开发用于系外行星和宇宙学研究的绿橙色天文梳

• 批准号: 1006503
• 负责人: Ronald Walsworth
• 金额: $ 32.5万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006503&HistoricalAwards=false
• 关键词: Collaborative; Research; Development; Green; Orange

The high-dispersion optical spectrographs that have thus far enabled the discovery of more than 400 extrasolar planets have a common susceptibility: the need for ultrastable, broadband, high-line-density, bright, and continuous wavelength calibration so that the small reflex velocities of the host stars can be precisely characterized over periods of weeks to years. One crucial technology for these investigations utilizes a mode-locked femtosecond pulsed laser - which produces a bright, regularly spaced set of emission features in frequency space - together with a Fabry-Perot filtering cavity to create the appropriate line-density, all locked to an atomic clock for long-term stability. These so-called "laser combs" have the potential for enabling radial velocity measurements to a precision 10 cm/s; thus the determination of the mass of Earth-like exoplanets should eventually be possible.Dr. Ronald Walsworth of the Harvard-Smithsonian Center for Astrophysics and Dr. Franz Kaertner of the Massachusetts Institute of Technology are planning to construct such a laser comb for the orange-green spectrum, a region well-suited to the detection of solar-type stars and therefore of stars in which a planet with an orbital period of ~1 yr would exist in the "life-zone", where surface water would be in liquid form. The team of investigators has an excellent track record in this area, having developed laser combs for the optical red and blue spectral regions. The new comb will be tested at the 1.5-m Whipple Observatory telescope on Mt. Hopkins, Az, and, when proven reliable, applied to an ongoing project at the 1.5-m telescope at Cerro Tololo Interamerican Observatory that is searching for exo-Earths orbiting stars in the very nearby alpha/beta-Centaurus star system. The activity will involve both women as both scientists and students, and the resulting time-controlled laser technology should have application well beyond astronomy. Funding for this work is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.

迄今为止，已经发现了400多颗太阳系外行星的高色散光谱仪都有一个共同的敏感性：需要超稳定、宽带、高线密度、明亮和连续的波长校准，以便在数周至数年的时间内精确地表征宿主恒星的小反射速度。 这些研究的关键技术之一是利用锁模飞秒脉冲激光器-在频率空间中产生明亮，规则间隔的发射特征集-以及法布里-珀罗滤波腔来创建适当的线密度，所有这些都锁定到原子钟以实现长期稳定性。 这些所谓的“激光梳”有可能使径向速度测量精度达到10厘米/秒;哈佛-史密森天体物理中心的罗纳德沃尔斯沃思博士和马萨诸塞州理工学院的弗兰兹凯尔特纳博士正计划建造这样一个用于橙绿色光谱的激光梳，该区域非常适合探测太阳型恒星，因此也非常适合探测轨道周期约为1年的行星将存在于“生命区”的恒星，那里的地表水将是液态的。 该研究小组在这一领域有着出色的记录，已经开发出了用于光学红色和蓝色光谱区域的激光梳。 新的梳子将在1.5米的维普莱天文台望远镜上进行测试。霍普金斯，亚利桑那州，当被证明是可靠的，应用于一个正在进行的项目，在1.5米望远镜在塞罗托洛洛美洲天文台，正在寻找外地球轨道的恒星在非常接近的阿尔法/贝塔半人马座星星系统。 这项活动将涉及妇女科学家和学生，由此产生的时间控制激光技术的应用范围应远远超出天文学。这项工作的资金由NSF的天文科学部通过其先进技术和仪器计划提供。