Near-infrared imaging of nearby galaxies

近红外波段的宽视场成像对我们银河系附近星系和恒星形成区域的研究很重要，但由于没有在波长长于^<1 \mu m>的板或大格式阵列灵敏，因此尚未进行。我们已经测试了一种独特的组合，一种带有大画幅阵列的红外相机和一种快速f比望远镜。探测器采用PtSi阵列。阵列尺寸为512x512像素，像素尺寸为26微米× 20微米。视场为14' x 11‘，像素分辨率为1.6 ’ x1.3 '，连接到基索天文台105cm施密特望远镜的主焦上。虽然阵列的量子效率较低，但相机出色的均匀性、稳定性和低读出噪声，加上望远镜的快速f比，使得在h波段曝光70分钟获得的图像中，校准精度达到0.1%的天空背景。采用PtSi 1040x1040芯片的相机目前正在开发中，使用的芯片具有改进的量子效率和填充系数。在基索·施密特望远镜的主要焦点处，视野将是18.4‘ x 18.4’。它将成为对大尺寸物体成像和调查的有力工具。我们计划在附近星系的光学和红外波长处获得多色光度测定。

Wide field imaging in near-infrared bands, which is important for studies of nearby galaxies and star forming regions in our Galaxy, has not been performed yet, since neither plates nor large format arrays sensitive at wavelength longer than ^<1 \mu m> were available. We have tested a unique combination of an infrared camera with a large format array and a fast f-ratio telescope. The detector used PtSi array. The array size is 512x512 pixels, and the pixel size is 26 micron x 20 micron. The field of view is 14' x 11' and the pixel resolution is 1.6" x1.3" when attached to the prime focus of the 105cm Schmidt telescope at Kiso observatory. Though the quantum efficiency of the array is low, the excellent uniformity, stability and low read-out noise of the camera combined with the fast f-ratio of the telescope resulted in a calibration accuracy of 0.1% of the sky background in a image obtained through 70 minute exposure in the H-band.A camera with PtSi 1040x1040 chip is now under development, using a chip with an improved quantum efficiency and filling factor. The field of view will be 18.4' x 18.4' at prime focus of the Kiso Schmidt telescope. It will be a powerful tool for imaging objects of large apparent size and for surveys. We are planning to obtain multi-color photometry at optical and infrared wavelengths of nearby galaxies.