MID-INFRARED SPECTROSCOPIC STUDY OF BRIGHT INFRARED GALAXIES

这项研究的一个独特技术方面是开发中红外法布里-珀罗成像仪(MIRFI)，它是为对位于10微米大气层窗口的中红外光谱线进行地面观测而设计的。MIRFI现在被调谐到观测来自霓离子的12.814微米的谱线，它由一个光谱分辨率为-2500的扫描法布里-珀罗涉仪和一个硅：P光导探测器阵列(5x5格式)组成，两者都是由液态氦冷却的。获得的灵敏度为1.6*10^&lt；-20；wcm；-2&gt；像素^-lt；-1&gt；(每光谱分辨率，17秒积分)足以观测到恒星形成的近红外线星系(星爆星系)的[Ne II]线。本研究的主要科学目的是通过[Ne II]线来研究新恒星爆发星系中心区的结构。红外明亮的星暴星系被尘埃严重遮挡，因此在光学波长上看不到，但在12.8微米处，尘埃消光几乎可以忽略不计。1995年4月，我们与NASA/IRTF(美国夏威夷莫纳克亚)进行了第一次观测，但由于天气恶劣，没有科学数据。1996年3月、10月和1997年3月，我们与美国怀俄明州的怀俄明红外天文台进行了多次观测，最终探测到了星暴星系M82的[Ne II]线，以及丰富的银河系超致密H II区(W51d，G29.96-0.02等)的[Ne II]通量数据。我们无法获得许多红外星系的数据：要做到这一点，我们需要非常好的天气条件。然而，MIRFI被证明在观测银河系天体方面是有效的，并将在不久的将来提供许多科学结果。

A unique technical aspect of this research is to develop a Mid-Infrared Fabry-Perot Imager (MIRFI), which is designed for ground-based observations of mid-infrared spectral lines located in the 10mum atomospheric window. MIRFI is now tuned to observe [Ne II] 12.814mum line from neon ions, and consists of a scanning Fabry-Perot interferometer with a spectral resolving power of -2500 and a Si : P photoconductive detector array (5x5 format), both are cooled by liquid-He. Achieved sensitivity of 1.6*10^<-20> Wcm^<-2>pixel^<-1> (per spectral resolution, 17sec integration) is sufficient to observe the [Ne II] line from neaby bright infrared galaxies with burst of star formation (starburst galaxies).Major scientific goal of this research is to investigate the structure of central region of neaby starburst galaxies by the [Ne II] line. Infrared luminous starburst galaxies are heavily obscured by dust and hence are not visible at optical wavelenth, but at 12.8mum dust extinction is almost negligible. We have made the first observing run with NASA/IRTF (Mauna Kea, Hawaii, USA) in April 1995, but no scientific data due to bad weather. In March and October 1996, and March 1997, we have made observing runs with Wyoming Infrared Observatory (Wyoming, USA), and finally detected [Ne II] line from the starburst galaxy M82, as well as rich [Ne II] flux data for Galactic ultracompact H II regions (W51d, G29.96-0.02, etc.). We could not obtain much data for infrared galaxies : to do this we need very good weather condition. However, MIRFI is proved to work efficiently for observation of Galactic objects and will provide much scientific results in the near future.