摘要
近年来,尽管对太阳系外行星探测的手段层出不穷,视向速度测量依然是探测太阳系外行星卓有成效的方法。随着探测太阳系外类地行星的呼声日益高涨,大幅度提高视向速度测量精度的任务迫在眉睫。为了提高天文光谱仪的稳定性,人们采用真空或恒温、恒压的仪器工作环境来确保视向速度的测量精度;同时,激光频率梳技术的出现又为天体视向速度测量系统提供了一个高精度的光谱定标源。将激光频率梳技术应用于天体视向速度测量是今后一段时间内的研究重点。
Discovering extrasolar planet has been pursued for a long time. Since the detec- tion of the first extrasolar planet was reported two decades ago, over seven hundred extrasolar planets were reported. Although the new technique is emerging, the radial velocity measure- ment is still the most productive technique for extrasolar planet hunting. As the earth ＇twin＇ is becoming the next goal, the precision of radial velocity measurement has to be dramati- cally improved. First of all, varies techniques were adopted to guarantee the stability of an astronomical spectrograph. One successful spectrograph is the HARPS, ESO operating in a vacuum tank. Another effort is put the spectrograph into a regulated instrument case whose temperature and air pressure are kept constant, like the PEPSI spectrograph. In the last decade, the laser frequency comb emerges as an idea] calibration source for the astronomical spectrograph. Based on a femtosecond laser referencing to a stable oscillator such as atomic clocks, the laser frequency comb could generate evenly distributed calibration lines in a wide spectral range with the precision of absolute frequencies better than 10-l~. It would ensure the precision of radial velocity measurement than current precision, meter per second. As for astronomical application are developing radial velocity measurement calibrated with ＇twin＇ into our scope in the near future. achieving centimeters per second, much better a broad range of laser frequency combs suitable in the laboratories around the world, and the laser frequency comb would bring more earth
出处
《天文学进展》
CSCD
北大核心
2012年第2期246-254,共9页
Progress In Astronomy
基金
国家自然科学基金(10978004)
关键词
光谱仪
视向速度测量
激光频率梳
spectrograph
radial velocity measurement
laser frequency comb
