XRT Response Functions: effect of new atomic data (Chianti ver. 10.0, released Nov-2020).

(5-Nov-2021, by Aki Takeda)
(19-Jan-2022, added notes about xrt_flux and xrt_teem.)
(5-Jan-2023, added added Ti_poly/Al_poly ratio curve as a NG pair.)

The XRT temperature response functions were recalculated, in response to the release of new Chianti atomic database version 10.0 in Nov-2020. The new atomic database (Chianti 10.0) turned out to make only negligible change on the XRT response functions calclated with the previous versions of Chianti(ver. 9.0.1).

quick review on the XRT temperature response basics.

1. The Response functions.

The solar spectra were calculated with the latest Chianti version 10.0, for 'coronal' (sun_coronal_1992_feldman_ext.abund), 'hybrid' (sun_coronal_2012_schmelz_ext.abund), and 'photospheric' (sun_photospheric_2015_scott.abund) abundances. Below are the previous versions for comparison. 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_flux1000(logte, f1,f2, tim, /corona)
IDL> flux_h = xrt_flux1000(logte, f1,f2, tim, /hybrid)
IDL> flux_p = xrt_flux1000(logte, f1,f2, tim, /photos)
IDL> flux_c9 = xrt_flux0901(logte, f1,f2, tim, /corona)
IDL> flux_h9 = xrt_flux0901(logte, f1,f2, tim, /hybrid)
IDL> flux_p9 = xrt_flux0901(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_flux1000.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_flux1000(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/Openthin-Be/Open med-Be/Openmed-Al/Open
Open/Al-meshOpen/thick-Al Open/thick-BeAl-poly/Ti-poly
Open/Ti-poly C-poly/Open

2. The Filter Ratios.

These plots shows that the CHIANTI ver 10.0 database makes no significant difference in most filter ratio curves relative to those with version 9.0.1.

(click each plot to show detailed info)

Al-poly/Al-meshthin-Be/Al-mesh thin-Be/Al-polymed-Be/Al-poly
med-Al/Al-polymed-Be/thin-Be med-Al/thin-Bemed-Al/med-Be
thick-Be/med-Althick-Be/thick-Al Ti-poly/Al-mesh thick-Be/med-Be
Ti-poly/Al-poly

3. XRT_TEEM modification.

XRT_TEEM_CH1000.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).
IDL> XRT_TEEM_CH1000, index1,data1,index2,data2,te,em, /corona
IDL> XRT_TEEM_CH1000, index1,data1,index2,data2,te,em, /hybrid
IDL> XRT_TEEM_CH1000, index1,data1,index2,data2,te,em, /photospheric
IDL> XRT_TEEM_CH1000, index1,data1,index2,data2,te,em, solar_spectrum='./solar_spectrum/solspec_ch1000_hybrid_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).