SXT Irradiance Study with the latest response funcetions
updated with Chianti DB ver. 10

6-feb-2023 : (AkT) initial version.
10-feb-2023 : data link and plot added.
04-mar-2023 : more plots added.

1. Brief history of the Yohkoh soft X-ray irradiance study.

  1. Initial study : Loren's 1999 paper, i.e., (Acton, Weston, and Bruner, JGR, 1999, vol.104, p.14827).
  2. SXT irradiance was used to study the relation between X-ray luminocity(Lx) and total magnetic flux(B), in Pevtsov et al.(2003) ApJ, vol.598, p.1387-1391.
  3. Loren had some collaboration work with other scientists (i.e., with J. Lean, using ssc7/sst7 and with J. Fox with ssc16 or later).
  4. My commitment started in Apr., 2008, as preparation of the poster presentation at the CAWSES meeting ("Solar Variability, Earth's Climate and the Space Environment"), held in Bozeman in June 2008. After a few months of intermission, I have revisited this theme since March, 2009.
  5. We frequently use the X-ray (1-8A) flux from GOES/XRS as a reference. Due to the need to use GOES data more efficiently, I regenerated the YDB/GOES week files for 1991-2001 using the NGDC/GOES data, in order to improve the data coverage (i.e., the former week files had lots of data gaps). The updated GOES weekly files were submitted to Sam Freeland in Jun., 2008, and now it's a part of official YDB.
  6. In 2018, Loren recalibrated SXT response functions by newly considering the contaminant accumulation on the pre-filter and the improved treatment of the stray light contamination (Acton, 2018, Sol. Phys., vol 293, pp.137). In response to this improvement, SXT irradiance was recalculated using the most recent Chianti atomic DB ver. 8.0. This work was performed with Nicole Albanese(Tufts Univ.) as a REU project of summer 2018 (Takeda et al., 2019, ApJ, vol 887, pp.225.).
  7. In 2022, Hinode/XRT irradiance was finalized by properly considering the stray light contamination and the contamination layers developed on CCD and also XRT analysis filters. Using this result, the Lx(XRT irradiance) vs B (total unsigned magnetic flux) relation initially studided by Pevtsov et al.(2003) was revisited. In order to compare with the old results, Yohkoh/SXT irradiance was also revisited.

2. Goal of this study.

Recalculate SXT irradiance with :

3. Method

4. Obtained data

link to the data directory

[click image to enlarge]

SXT irradadiance 3-30A with FOV 0.5,0.9 & 1.2Rs 2.8-36.6A (same as Pevtsov et al 2003)
SXT irradadiance 3-30A, FOV: 1.1Rs vs 1.2Rs shifted curves (0.933, 0.904, 0.927)
SXT irradadiance 3-30A, FOV: 0.9Rs vs 1.2Rs shifted curves (0.507, 0.442, 0.468)
SXT irradadiance 3-30A, FOV: 0.9Rs vs 1.2Rs shifted curves (0.556, 0.495, 0.490, 0.490, 0.457,
0.437, 0.462, 0.457,0.473,0.478)
SXT irradadiance 3-30A, FOV: 0.7Rs vs 0.9Rs shifted curves (0.638, 0.646, 0.589, 0.575, 0.562,
0.525, 0.556, 0.550, 0.617, 0.603)