Project Overview

• Analyze x-ray irradiance for full solar cycle
• Characterize dependence of the irradiance on solar latitudes
• Inspect irradiance dependence on specific solar structures

Mid-research Reminders

• Hinode (Sunrise)
  • Solar Optical Telescope (SOT)
  • Extreme Ultraviolet Imaging Spectrometer (EIS)
  • X-Ray Telescope (XRT)
• Analyzed data
  • XRT Synoptic Compotie Database at MSU
  • Composite images
    • Three exposures
      • Long, medium, short
      • Increased dynamic range
    • Data masked to 1.1 solar radii
• Aluminum mesh & Titanium poly filters
• Movies created

Coronal Temperature Analysis: Filter ratio method

• 2008-2012
• 
  • Energy of photons measured using the energy of electrons from the ccd
  • N_e is electron density
  • P is emissivity as function of wavelength
  • η_i is telescope effective area, where i denotes filter number
    • Product of aperature, mirror, filter, ccd quantum efficiency
• Assuming isothermal plasmas
• 
• 
  • This gives the filter ratio as a function of temperature (T)
• Each filter has different temperature response
  • Al_mesh able to see cooler plasmas than ti_poly

Assuming coronal elemental abbundance:

• A video of the 2010 al_mesh and ti_poly filter comparisons seen here.

Results

• Temperature and volume emission measure plots can be seen here.

Summary

• Full sun coronal temperature and emission measure calculated using full-sun images
  • X-ray images
  • 2008-2012
• 2009 temperature 10^6.06 (~1.1MK) at solar minimum
• Temperature increase to 10^6.2 (~1.6MK) in 2011
• Volume emission measure given by N_e² V
  Uses electron ccd count
• Data problems
  • January 2008 index error
    • Filter problems
  • May 2012 calibration shift begins
    • Caused by increased stray light leak

In Conclusion

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Sources

Hara, H. et al "High-Temperature Plasmas in Active Regions Observed with the Soft X-Ray Telescope aboard Yohkoh." Publ. Astron. Soc. Japan 44 (1992): 135-140. Print.

Narukage, N. et al "Coronal-Temperature-Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration" Solar Physics (2011): 169-236. Print.