RESIK & Diogeness NEWS
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(Week 20, 2003, 12 May - 18 May)
In the display above (click to enlarge), the solar X-ray fluence seen by RESIK (black points) is plotted atop GOES red line. Only periods with good spectral measurements are indicated. The total number of good spectral measurements is given in the title line.
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Operation mode: |
1 s DGI has been used '3rd order reflections' (ORD3) is
used as stand-by mode.
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Calibrations made: |
No calibrations made
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ADS Settings: |
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| (ORD1) HV: Det. A - 1480 V, Det. B - 1419 V. | (ORD3) HV: Det. A - 1389 V, Det. B - 1328 V. | ||||||
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Channel |
l Band |
ADS |
Channel |
l Band |
ADS | ||
| #1 | #2 | 3.37 - 3.88 Å | 115 - 195 | #1 | #2 | 1.16 - 1.29 Å | 110 - 230 |
| #2 | #0 | 3.82 - 4.33 Å | 75 - 170 | #2 | #0 | 1.27 - 1.44 Å | 110 - 230 |
| #3 | #3 | 4.31 - 4.89 Å | 170 - 250 | #3 | #3 | 1.44 - 1.63 Å | 110 - 230 |
| #4 | #1 | 4.96 - 6.09 Å | 145 - 205 | #4 | #1 | 1.65 - 2.03 Å | 140 - 230 |
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 spectroscopic notation
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Data gaps due to missing/bad telemetry: ~ 0.5 h.
Note, that the link to the catalogue page is now: http://www.cbk.pan.wroc.pl/resik_catalogue.htm.
Another Potassium Enhanced Flares
In the paper by Phillips et al., 2003 (ApJ, 589, L113) the solar flare abundance for potassium has been determined based on the RESIK spectra as observed for long duration events. It was found that the abundance of potassium is a factor of 3 times photospheric. Here we present the spectra for other flares in which the potassium lines are also enhanced in comparison with what we expect based on the photospheric K abundance. This time the flares chosen for the presentation belong to the class of short duration events lasting several minutes. They took place at different positions on the solar disc and were of different importance in GOES classification.
In Figure 1 we present the parts of RESIK catalogue pages for 3 flares namely:
1) 11 July 2002, M5.8
(start at 14:44:00 UT, max. at 14:51:00 UT and the end at 14:57:00 UT) located at N21E58
2) 21 Feb. 2003, C4.3 (19:46:00 UT, 19:50:00 UT, 19:54:00 UT) at N15E01
3) 28 Feb. 2003, C1.7 (06:20:00 UT, 06:28:00 UT, 06:34:00 UT) at N15E88
Figure 1. The upper panels of RESIK catalogue pages for 3 short duration flares. As can be noticed they are of different importance (M5.8, C4.3, C1.7) and are located at different positions on the solar disc (N21E58, N15E01, N15E88).
In Figure 2 the RESIK spectra are presented for these three flares. The lines emitted by potassium, argon, and sulphur ions are present in these spectra. However only the He-like K triplet is indicated in the Figure (K XVIII, 3.532 Å ÷ 3.571 Å). For the line identification of other lines observed in the four RESIK channels see Weekly 40, 2002. The other examples of spectra for short duration events which indicate for enhanced intensities of potassium lines one can find in Weekly 08, 2003 and Weekly 19, 2003. Those are for the flares on 22 Feb. 2003 at ~ 09:29 UT (C5.8) and 11 Dec. 2002 at ~14:10 UT (C7.2). Based on the photospheric K abundance it is believed that potassium belongs to rather „poor” element abundance class. The observations of increased intensity of K XVIII triplet in the spectra of short duration flares confirm the different coronal and photospheric plasma composition deduced from the RESIK spectra as observed for long duration events.
Figure 2. The RESIK spectra for three selected flares: on 11 July 2002 (1), 21 February 2003 (2) and on 28 February 2003 (3). The triplet of K XVIII ion is indicated. The identification of other lines one can find in Weekly 40, 2002.
The observations of potassium lines are important as up to the RESIK experiment there is in fact only one other X-ray potassium line observation (1s2 – 1s3p line at 3.01 Å). This was reported in 1985 in the paper by Doschek, Feldman and Seely in MNRAS, 217, p. 317.
Prepared by: Barbara Sylwester bs@cbk.pan.wroc.pl and Janusz Sylwester js@cbk.pan.wroc.pl
The report presented has been done in "real time" and so it may contain jargon, blunders, or trivialities. We do not have also an English native speaker in our Wroclaw group!
We would be happy to discuss problems mentioned above in more details if necessary.
RESIK data are in the open public domain and can be requested from: http://surfwww.mssl.ucl.ac.uk/surf/data_request.html.
Previous RESIK_weekly notes are in the archive: http://www.cbk.pan.wroc.pl/resik_archive.htm
Page made on 23 May 2003 by: Anna Kepa ak@cbk.pan.wroc.pl and Jarek Bakala jb@cbk.pan.wroc.pl
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