面向时域天文的高精度测光研究

项目名称： 面向时域天文的高精度测光研究

项目编号： No.11503018

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 贾鹏

作者单位： 太原理工大学

项目金额： 26万元

中文摘要： 大视场测光巡天为时域天文学研究积累了大量数据。对于大视场测光，为提高观测效率，往往同时对视场内多个目标连续观测。由于观测视场大、目标多，快速、高精度地测光以最大限度发挥望远镜的观测能力成为一个新的挑战。本项目将模糊数学理论引入，建立一种描述大视场成像的空间可变点扩散函数模型，在此基础上，提出满足大视场巡天特点的点扩散函数模型拟合测光方法。这种方法利用激光导星作为位置固定、亮度稳定的参考目标，结合空间可变点扩散函数模型，获得点扩散函数的估计值，进而实现点扩散函数模型拟合测光。这种方法可在大视场内（1角分左右）将测光的系统误差降低至大气闪烁引起的误差之内（1%左右），观测效率高，数据后期处理速度快。研究结果可为我国未来在云南天文台2.4米望远镜、南极昆仑暗宇宙巡天望远镜（KDUST）及新一代大视场巡天望远镜等设备上开展的时域大视场高精度测光巡天提供一种新思路和有效手段。

中文关键词： 时域天文学；大视场测光数据；点扩散函数模型拟合测光；数值模拟；图像处理

英文摘要： Wide field photometry sky survey will bring huge data for time domain astronomy. To increase observation efficiency, continuous observation of multiple stars is commonly applied. But the number of stars brings a new challenge to fast and high precision photometry. We propose a spatially variable Point Spread Function (PSF) model based on fuzzy math in this project to describe the PSF of images captured by the wide field telescopes. Based on this model, a high precision psf-fitting photometry method is proposed, which uses the PSF generated by laser guide stars as reference and the spatially variable PSF as frame to estimate PSF in the whole image plane, and then obtains the magnitude of stars with the estimated PSF. This method is fast and easy to accelerate data processing with batch mode. The system error of photometry in this method is within the error brought by atmospheric scintillation (1% to 0.1%) in a wide field of view (around 1 arcmin). The results of this project will provide a new idea and an effective method for the high precision time domain photometry sky surveying carried out by 2.4 m telescope in YNAO, KDUST and New Generation wide field sky survey telescope etc.

英文关键词： Time Domain Astronomy;Wide Field Photometry Data;PSF-fitting Photometry;Numerical Simulation;Image Processing