NBS窄波段数据扣除连续谱的批处理方法  

The Batch Processing Method of Continuum Subtraction for Narrow Band Survey

作　　者：李垚 武朝剑 李彬 庄芮 赵海斌[4] 姚永强[1] 吴宏[1,3] LI Yao;WU Chao-jian;LI Bin;ZHUANG Rui;ZHAO Hai-bin;YAO Yong-qiang;WU Hong(National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100012,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory for Optical Astronomy,National Astronomical Observatories,Chinese Acade-my of Sciences,Beijing 100012,China;Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210034,China;University of Science and Technology of China,Hefei 230026,China;University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中国科学院国家天文台,北京100101 [2]中国科学院大学天文与空间科学学院,北京100049 [3]中国科学院国家天文台光学天文重点实验室,北京100101 [4]中国科学院紫金山天文台,南京210034 [5]中国科学技术大学,合肥230026 [6]北京科技大学,北京100083

出　　处：《天文学进展》2021年第2期234-248,共15页Progress In Astronomy

基　　金：国家自然科学基金(12073051,11403061,11733006,11873063)。

摘　　要：光学窄波段观测能够表征发射线天体清晰的结构,是研究发射线天体的重要手段,对恒星形成区、类星体窄线区、星系H Ⅱ区、星际介质等方面的研究具有重要意义。消除窄波段图像的连续谱是常用的搜寻发射线天体的方法,传统上连续谱扣除的解决方法是根据像素位置、方向和强度来调整图像对齐,然后进行两幅图像的相减,但是其过程繁琐不适合用于巡天大数据减连续谱。基于窄波段巡天项目(narrowbandsurvey,NBS)[S Ⅱ]波段数据,提出一种通过自动匹配宽、窄波段流量数据与星像轮廓方法。该方法自动匹配图像天文位置,避免了图像像素对齐过程中像素位置调整和图像选择。通过快速探测宽、窄视场图像的流量和星像,完成相应匹配,提高图像相减效率。根据实验结果,减完连续谱的图像中大概70%亮星能被扣除干净,并且能够获取到较清晰的发射线天体结构。目前该方法已用于搜寻Herbig-Haro天体(简称HH天体),超新星遗迹候选体选取等工作中。Optical narrow-band observation can characterize the clear structure of the emission line objects,Which is important to study the star-forming region,quasar narrowline region,H Ⅱ region,and interstellar medium.Narrow Band Survey(NBS)is a fully photometric CCD survey of the Northern Galactic Plane,which targeted the inner regions of the Northern plane over the latitude range of􀀀5°<b<+5°and a longitude range of 29°<l<215°covering a total of 1800 deg2.NBS was conducted with three narrow-band filters:H filter(80 Å full width at half-maximum,central wavelength at 6563 Å),[S Ⅱ]filter(80 Å full width at half-maximum,central wavelength at 6765 Å)and[O Ⅲ]filter(80 Å full width at half-maximum,central wavelength at 5007 Å).The continuum subtraction is a common method to search for emission-line objects forms the narrow-band images.Traditionally these have been dealt with by carefully registering the images in terms of position,orientation and intensity,and subtracting them from different bands images.This paper uses the[S Ⅱ]band data of the NBS,proposes a method of subtracting continuum.We introduced SWARP and Source Extract,the SWARP software can automatically match the astronomical positions of the respective sources of the two images,avoid pixel position adjustment and image rotation;The Source Extract software can quickly detect the flux and star image in the wide-band and narrow-band image,and accomplish the flux matching and PSF matching by Python,finally use SWARP to do the batch processing of image subtraction.Compared with the traditional method,this method can improve the efficiency.At present,this method has been applied in searching for the Herbig-Haro objects and Supernova Remnant candidates.

关 键 词：窄波段巡天 减连续谱 减天光背景 图像数据处理 

分 类 号：P155[天文地球—天文学]