2007/12/08-10 Hinode Workshop in China 1

XRT Analysis Software

R. Kano (NAOJ)

and XRT Teams

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Analysis Guide

XRT Analysis Guide (XAG) is distributed in SSW as $SSW/hinode/xrt/docs/XAG.pdf.

In the guide, ….For data analysis problems, contact xrt_mana

ger[at]cfa.harvard.eduFor science discussions, contact xrt_science

[at]cfa.harvard.edu

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Outline of XRT Analysis

Get Level-0 data Download Level-0 data from DARTS or other mirror sites. Define XRT FITS files (Level-0 data). Read file(s)

Create Level-1 data(= Calibration) Calibration… Only for morphological studies, if necessary, touch-up the conta

mination spots.

Create Level-2 data For example, to calculate temperature and emission measure

Morphological studies are available.

Studies of spatial and temporal variation are available.

Studies of energetics are available.

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Get Level-0 data.

Download Level-0 data from DARTS or other mirror sites. Downloaded FITS files are named as

XRTYYYYMMDD_hhmmss.s.fits,and stored in the directory of

YYYY/MM/DD/Hhh00.

Define XRT FITS files (Level-0 data). Set the name of directory where the downloaded FITS files are store

d as dir_name, then file=file_search(dir_name, '*.fits')

Read file(s) read_xrt, file, index0, data0

which is identical with mreadfits, file, index0, data0. The unit of data0 is DN (data number), which corresponds to about 57 ele

ctrons.

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Selection of Images

Important parameters in index index.date_obs : Start time of exposure. index.exptime : Exposure duration in sec. index.ec_fw1_ : Filter name in FW1. index.ec_fw2_ : Filter name in FW2. index.chip_sum : Spatial resolution in CCD pixel. index.rsize_col : Horizontal size in CCD pixel. index.rsize_row : Vertical size in CCD pixel.

Example to select Ti/poly. images. mreadfits, file, index ss = where( (index.ec_fw1_ eq ‘Open’) and

(index.ec_fw2_ eq ‘Ti_poly’) ) mreadfits, file(ss), index0, data0

FW2

FW1

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Create Level-1 data: Calibration

Calibration xrt_prep, index0, data0, index1, data1

Data base ( or detailed model ) of dark images will be distributed through SSWDB in near future.

For CCD-bias and dark subtraction & exposure normalization, it is almost the same with the following equations, if you have dark_image with the same exposure duration. data1 = ( data0 – dark_image ) / index0.exptime

XRT images’ alignment xrt_jitter, index, off data_output = image_translate( data_input, off )

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To Download of Dark Images

Recently we take dark images during observations at a low cadence (10min-a few hours) with the same FOV format.

At this point, for better quantitative analysis, it is better to use dark images with the same FOV format taken during the observation.

Caution: Exposure duration of dark images shown by index.exptime is m

eaningless, because no shutter motion. Accumulation duration shown by index.exccdex indicate the len

gth of dark “exposure”.

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Create Level-1 data

Only for morphological studies, if necessary, touch-up the contamination spots.xrt_tup_contam,index0,data0,index1,data1

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Create Level-2 data:Example of Filter-Ratio Method. Filter-Ratio Method

xrt_teem, index1[0], data1[*,*,0] , index1[1], data1[*,*,1] , te, em, te_err, em_err

ne = 0.5 em – 0.5 alog10(V) ,where V(cm3) is the volume of the observin

g plasma.

Narukage et al. 2008 (TBD).

image taken with one filter

image taken with the other filter

logT(K) logVEM(cm-5) errors in log scalelogNe(cm-3)

It will be installed into SSW soon.

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Create Level-2 data:Caluculate XRT response Effective Area

ea = xrt_eff_area( lambda ) The Chianti package is SSW is also useful to understa

nd the XRT response.

Temperature Responset_resp = xrt_flux( te, FW1_ID, FW2_ID, /DN)

Filter-Ratio Model Functionratio = t_resp0 / t_resp1

Narukage et al. 2008 (TBD).It will be installed into SSW soon.

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Summary

XRT software and database are distributed as SSW and SSWDB, although more progress of them is necessary.

XRT Analysis Guide (XAG) is distributed in SSW as $SSW/hinode/xrt/docs/XAG.pdf.

The programs related with the filter-ratio method will be distributed, just after we finish the on-orbit re-calibration of XRT. The results of on-orbit re-calibration will be submitted as

“Narukage et al. 2008, Solar Physics”.

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Finally

We would like to share to develop better software.

When you create any useful programs, please let us know.