3.光谱处理 Pre-Extraction Reductions for CCD Data Read data from disk and convert data to a format compatible with software 2. Inspect the original images and discard bad ones 3. Flag all the known faulty pixels or replace them with reasonable values Create master bias and dark images to remove the dark and bias signal from raw images of targets 5. Create a master flat field frame defining the pixel-to- pixel sensitivity variations and then flat field each of the images 6 Align and add the individual images of each target to produce a master image of the object !!Same procedures for 2-D photometry and spectroscopy
Pre-Extraction Reductions for CCD Data 1. Read data from disk and convert data to a format compatible with software 2. Inspect the original images and discard bad ones 3. Flag all the known faulty pixels or replace them with reasonable values 4. Create master bias and dark images to remove the dark and bias signal from raw images of targets 5. Create a master flat field frame defining the pixel-topixel sensitivity variations and then flat field each of the images 6. Align and add the individual images of each target to produce a master image of the object !!! Same procedures for 2-D photometry and spectroscopy 3. 光谱处理
Procedure for spectroscopy ldentify cosmic ray,bad pixels 2. De-bias 3. Flat-fielding 4. Extraction 5. Wavelength calibration 6. Flux calibration 7. De-redshift 8.Spectral line identification
1. Identify cosmic ray，bad pixels 2. De-bias 3. Flat-fielding 4. Extraction 5. Wavelength calibration 6. Flux calibration 7. De-redshift 8. Spectral line identification Procedure for spectroscopy
595 600 605 610 615 620 625 Domeflat.(圆项平场) 5000 10000 15000 20000 25000 Skyflat（天空平场) 5000 10000 15000 20000 25000 30000 35000 40000 45000 500
2022/5/6 孔旭 13 Bias（本底） Domeflat（圆顶平场） Skyflat（天空平场） Bias（本底）
IRAF ■ IRAF is the Image Reduction and Analysis Facility a general purpose software system for the reduction and analysis of astronomical data https://iraf-community.github.io 初始化：mkiraf今login.cl、uparm/ 登陆退出：cl;logout 在线帮助：help splot;help display ■ 参数设置：epar;lpar ■ 星示图象：display*.fits or display*.imh 格式转化：rfits;wfits
IRAF n IRAF is the Image Reduction and Analysis Facility q a general purpose software system for the reduction and analysis of astronomical data n https://iraf-community.github.io n 初始化：mkiraf àlogin.cl、 uparm/ n 登陆退出：cl；logout n 在线帮助：help splot ；help display n 参数设置：epar；lpar n 显示图象：display *.fits or display *.imh n 格式转化：rfits；wfits
IRAF 显示行或列的一维图像：implot*.fits ■ 处理本底：zerocombine 产生平场：flatcombine 处理数据：ccdproc 检查浏览图像文件：imhead*,fits;ds9*,fits
IRAF n 显示行或列的一维图像：implot *.fits n 处理本底：zerocombine n 产生平场：flatcombine n 处理数据：ccdproc n 检查浏览图像文件：imhead *.fits；ds9 *.fits