Solar Soft X-ray Irradiance with Hinode/XRT

Project descriptions

With this archive, we can study solar activities in terms of the Sun's radiation in soft X-ray wavelengths. In this project, we will process the XRT/SCIA images taken from 2006 to present to derive the soft X-ray irradiance during this period. We will learn how to process Hinode/XRT FITS data for quantitative analysis using the data analysis software IDL(Interactive Data Language): data selection, derivation of temperature and emission measure, calculation of the XRT irradiance in the physical unit (W/m^2), etc. This project is continued from 2021. This year, we will put emphasis on the data calibration to correct characteristic change of the instrument over 15 years of operation, and comparison with the observations by other instruments measuring the solar cycle variation.

As a bonus, the student will have a few opportunities to watch and learn how an international satellite project like Hinode is operated. As one of US institutes participating the Hinode satellite operation, we have a duty week in July, in which we take control of the XRT observation.

Weekly goals

• Week 1 (5/30 -- 6/2) :
  • attend Python and IDL tutorials.
  • Read "Encyclopedia of the Sun" to study background of the project (sections 8.4, 8.5.).

• Week 2 (6/5 -- 6/9) :
  • Discuss "Encyclopedia of the Sun", sections 8.4, 8.5.
  • Introduction to Hinode project and XRT instruments.
  • Introduction to XRT data handling with IDL.
    • read XRT level0 data (sample_read.pro)
    • calibrate XRT data (sample_prep.pro)
    • make a composite image(sample_comp.pro)
    • Get to know about SCIA data.
  • Preparation for the short presentation on Friday 2pm.
  
  
• Week 3 (6/12 -- 6/16) :
  • Understand the project goal and steps to get there.
    • step 1: data selection (find usable image pairs of Al_mesh and Al_poly)
    • step 2: collect total intensity within 1.1 Rs.
    • step 3: derive averaged temperature(Te) and Emisison Measure(EM) for each pair.
    • step 4: convert Te and EM to solar irradiance in the unit of W/m^2.
  • Finish Step 1 and 2.
  • Learn how to connect monthly files.
  
  
• Week 4 (6/19 -- 6/23) :
  • Learn about Filter Ratio Method and finish Step 3.
  • Learn how to make IDL procedures and process in a sequence
  • Present at the bi-weekly group meeting.
  
  
• Week 5 (6/26 -- 6/30) :
  • Learn about coronal emission mechanism
  • Learn how to calculate irradiance.
  • Finish Step 4
  
  
• Week 6 (7/3 -- 7/7) :
  • Expand data period from 2015 to date (use file pairs found by the past analysis).
  • Prepare for the mid-term presentation (well done!).
  
  
• Week 7 (7/10 -- 7/14) :
  • Expand data period from 2015 to date (continued).
  • Start independent project (sharing motivation).
  • Mask image consideration.
  
  
• Week 8 (7/17 -- 7/21) :
  • independent study : latitude dependence of X-ray irradiance.
  • mask shape determination
  • program modification
  
  
• Week 9 (7/24 -- 7/28) :
• Week 10 (7/31-- 8/4) :
  

  Resources

  • Section 8.4 and 8.5 of "Encyclopedia of the Sun" by Kenneth R. Lang (2001) Cambridge University Press
  • about XRT Synoptic Composite Images
  • Other References
  • IDL sample programs
  • IDL Basics (old version, but still helps)
  
  * Image created by S. Boland, 2022.

  memo for the 6/13 meeting

  • The Filter Ratio Method
  • XRT's effective area functions and spectral response functions
  • XRT's CCD camera gain constant is 57 electrons/DN

  memo for the 6/14 meeting

  • Performed image pair selection with Anne and Rhiannon independently (2022/03---2023/04).
    Removal list by Anne and by Rhiannon and final .
  • Weird images found in 2022.
    20220505 06:28:09 : noisy square with bright bar
    20220702 06:24:28 : noisy square with bright bar
    20220721 23:12:06 : telescope moved while taking synoptic image set (program started too early)

  memo for the 6/26 meeting

  • coronal emission mechanisms and sample X-ray spectrum
  • CHIANTI atomic DB

  memo for the 7/21 meeting

  Anne's irradiance sample plots
  
  
  
  Aki Takeda (Research Scientist, Dept. of Physics at MSU)