XRT Response Functions: effect of new atomic data (Chianti DB
ver. 11.0.2, released Aug-2025).
(30-Dec-2025, by Aki Takeda)
The XRT temperature response functions were recalculated, in response to
the release of new Chianti atomic database version 11.0.2 in August 2025.
The new atomic database (Chianti 11.0.2) introduces a new ionization-equilbrium
file, which is created 'on-the-fly' when required. In the previous versions,
'chianti.ioneq' was assumed.
quick review on the XRT temperature response basics.
1. The Response functions.
The solar spectra were calculated with the latest Chianti version 11.0.2.
From the previous version (10.1), the 'coronal' and 'photospheric' abundance
were updated to 'sun_coronal_2021_chianti.abund' and
'sun_photospheric_2021_asplund.abund', respectively.
For comparison, the spectral files using the traditional coronal abundance
files (sun_coronal_1992_feldman_ext.abund, and sun_coronal_2012_schmelz_ext.abund)
were also calculated.
- (a) solspec_ch1102_cr2021chianti_adv.genx
- (b) solspec_ch1102_ph2021asplund_adv.genx
Below are the previous versions for comparison.
- (c) solspec_ch1010_cr2021chianti_chianti.genx
- (d) solspec_ch1010_ph2021asplund_chianti.genx
Then I modified XRT_FLUX.PRO so that it can access the above spectrum files
by setting the corresponding keyword. Examples of usage are as follows
(including older versions).
IDL> flux_c = xrt_flux1102(logte, f1,f2, tim, /corona)
IDL> flux_c1992 = xrt_flux1102(logte, f1,f2, tim, /cr1992)
IDL> flux_h2012 = xrt_flux1102(logte, f1,f2, tim, /hybrid)
IDL> flux_p = xrt_flux1102(logte, f1,f2, tim, /photos)
IDL> flux10_c = xrt_flux1010(logte, f1,f2, tim, /corona)
IDL> flux10_c1992 = xrt_flux1010(logte, f1,f2, tim, /cr1992)
IDL> flux10_h2012 = xrt_flux1010(logte, f1,f2, tim, /hybrid)
IDL> flux10_p = xrt_flux1010(logte, f1,f2, tim, /photos)
[NOTE] The more generalized function, XRT_FLUX_CH.PRO was developed to
calculate the flux with the most recent solar spectral data. This function
uses the most recent solar spectrum by default, and can also use
the older versions by specifying in the keyword. See the program header
about how to use (e.g., $SSW/hinode/xrt/idl/response/xrt_flux_ch.pro).
[ Example of calculating XRT response functions ]
For details, see the description of
http://solar.physics.montana.edu/HINODE/XRT/xrt_ssw/xrt_flux1010.pro.
IDL> tim='1-may-2017 00:00' ; change as needed.
IDL> f1=0 & f2=2 ; for Open/Ti-poly
IDL> logte = 5.+findgen(61)*0.05 ; prepare a temperature array
IDL> flux = xrt_flux1102(logte, f1,f2, tim, /corona)
Below are the response functions of all the X-ray analysis filters available
at XRT. It is known that the contamination accumulated on the CCD modifies
the XRT response functions. As the amount of contamination varies with time,
response functions are time-dependant. For the later convenience of analysis,
the following response functions were calculated for the contamination level
as of 12-Nov-2006.
(Click each plot to show details)
| Al-poly/Open | thin-Be/Open |
med-Be/Open | med-Al/Open |
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| Open/Al-mesh | Open/thick-Al |
Open/thick-Be | Al-poly/Ti-poly |
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| Open/Ti-poly | Open/C-poly | | |
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2. The Filter Ratios.
These plots shows that the CHIANTI ver 10.1 database makes no significant
difference in most filter ratio curves relative to those with version 10.0,
except some thin filter pairs like Al_mesh/Ti_poly.
(click each plot to show detailed info)
| Al-poly/Al-mesh |
Ti-poly/Al-mesh | thin-Be/Al-mesh | thin-Be/Al-poly |
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| med-Be/Al-poly | med-Be/thin-Be |
med-Al/Al-poly | med-Al/thin-Be (NG?) |
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| thick-Al/med-Al | thick-Be/med-Be | thick-Be/med-Al |
thick-Be/thick-Al |
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| Ti-poly/Al-poly (NG pair) | med-Al/med-Be (NG pair) |
| |
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3. XRT_TEEM modification.
XRT_TEEM_CH1102.PRO was prepared.
Instead of directly modifying XRT_TEEM, I made a wrapper procedure
that sets up the arrays of specified solar spectrum, and passes them
to XRT_TEEM. You can get it from
http://solar.physics.montana.edu/HINODE/XRT/xrt_ssw (or Ylstone:/disk/yla/software/xrt_ssw).
- [Note 1] : Be sure to run with the latest version of XRT_TEEM
and XRT_FLUX (both v2013-Nov-04), that includes new filter
calibration (with CAL keyword). The version modified by Takeda after 2011
does not support this recalibration.
- [Note 2] : If you download this procedure, do it together with the
solar spectrum files listed in the above ('solspec_ch1102_cr2021chianti_chianti.genx'
is required at least). They are also found in the same directory.
- [Note 3] : You might need to edit/change the path of the solar spectrum
file directory(DIR_SPEC). They should eventuraly be sent to $SSW_XRT,
but for now they are stored in
/disk/yla/software/xrt_ssw/solar_spectrum, that is the current setting
of DIR_SPEC defined at the begining of the procedure.
IDL> XRT_TEEM_CH1102, index1,data1,index2,data2,te,em, /corona ; reads solspec_ch1102_cr2021chianti_chianti.genx
IDL> XRT_TEEM_CH1102, index1,data1,index2,data2,te,em, /photospheric ; reads solspec_ch1102_ph2021asplund_chianti.genx
IDL> XRT_TEEM_CH1102, index1,data1,index2,data2,te,em, /hybrid ; reads solspec_ch1102_cr2012schmelz_chianti.genx
IDL> XRT_TEEM_CH1102, index1,data1,index2,data2,te,em, /cr1992 ; reads solspec_ch1102_cr1992feldman_chianti.genx
IDL> XRT_TEEM_CH1102, index1,data1,index2,data2,te,em, solar_spectrum='./solar_spectrum/solspec_ch1102_ph2015scott_chianti.genx'
[NOTE] The more generalized function, XRT_TEEM_CH.PRO was developed to
calculate the flux with the most recent solar spectral data. This function
uses the most recent solar spectrum by default, and can also use
the older versions by specifying in the keyword. See the program header
for how to use (e.g., $SSW/hinode/xrt/idl/response/xrt_teem_ch.pro).