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Top > Suzaku > Data Process > History > V1.4.2.9

Processing Version

Last Updated on 2007 April 16

Suzaku data are available from DARTS.

Old versions are summarized in the history page.

Released 2007-04-13
Mk1stfitsver mk1stfits20060227
Softver Hea_11Sep2006_V6.1.1_Suzaku_11Sep2006_V1.2
CALDBVER hxd20070409_xis20070409_xrt20060720_xrs20060410
Changes Internal update of the processing pipeline.

Released 2007-03-09
Mk1stfitsver mk1stfits20060227
Softver Hea_11Sep2006_V6.1.1_Suzaku_11Sep2006_V1.2
CALDBVER hxd20070302_xis20070302_xrt20060720_xrs20060410

Released 2007-02-15
Mk1stfitsver mk1stfits20060227
Softver Hea_11Sep2006_V6.1.1_Suzaku_11Sep2006_V1.2
CALDBVER hxd20070131_xis20070206_xrt20060720_xrs20060410

Released 2007-02-01
Mk1stfitsver mk1stfits20060227
Softver Hea_11Sep2006_V6.1.1_Suzaku_11Sep2006_V1.2
CALDBVER hxd20061226_xis20061226_xrt20060720_xrs20060410

Currently, the spaced-row charge injection (SCI) is applied to XIS observations by default. However, the SCI completely changes charge transfer inefficiency (CTI). Consequently, current PI values in XIS data with the SCI are not correct, since the PI values are calculated by using the CTI for no-SCI observations in the current data process. Current xisrmfgen and xissimarfgen also do not support the SCI. You will be able to analyze SCI data using new ftools and calibration files to be released in June. These new ftools and calibration are implemented in the version 2.0 processing, with which all the data will be reprocessed.

Notes is a minor update of v1.2.x.x processing. The differences which affect the scientific data are only the CALDB files (XIS microcode and GSO gain-history), and the products' quality is the same as that of 1.2.x.x, and hence any re-processing of 1.2.x.x products will not be performed.

The differences from v1.2.x.x processing are:
- Force extractor to use DETX/DETY for XIS spectra. 
- Fix bug in creating BURST_ID in
- fmemsort cleaned WEL event files. 
- Use CALDB for hxdpi if it covers the time interval of the data. 
  This overrides the hxdmkgainhist output. (
- Turn off GSO .pi file creation if the cleaned GSO event
  file was calibrated with the GSO gain histroy file calculated
  during the pipeline. This data is not usable at the product
  level. The LCs are left in place.
- The STATUS range is set to 0:262143 for both single and 
  multiple XIS input files (it was 0:131072 for the multiple
  input file case in v.1.2). 

Notes (same as that of v1.2.x.x)

  • XIS files:
    • Timing mode data are not processed.
    • Dead time is not calculated when the burst mode option is used.
    • Some of the events might have invalid PI values (PI=4095), when the burst and window options are combined. These events are effectively removed from the subsequent analysis, resulting in a slight reduction in normalization. See Suzaku Memo 2006-20 for details.
    • Details of the limitations associated in the data processing are summarized in Suzaku Memo 2006-16.
    • The XIS team is preparing background database and tools to be used by Guest Observers for extended source analysis. The temporal version which covers from 2005 September to 2006 May is available at XIS data analysis page.
  • HXD files:
    • GSO data in this release are processed by use of the temporary gain correction file which is automatically created in the pipe-line processing, and hence the systematic uncertainty is rather large. This sometimes causes improper data screening and the resultant cleaned event files are wrong or even non-existent. To obtain more precise gain correction, including the short-term gain variation, observers must perform a re-processing with the latest CALDB file by themselves. The detailed procedures are explained here and other manuals.
    • The accuracy of non-X-ray background (NXB) model is crucial to precisely obtain scientific results, for a non-imaging hard X-ray instrument like HXD. The HXD team has been investigating spectral and temporal behaviors of in-orbit detector background. A "background estimator" tool will be released as a part of HEADAS package in future, but it is still under development. Until the tool is released, the latest results of the NXB modeling are distributed as "background event files" from the Suzaku Web page, with 2-4 weeks or 4-6 weeks delay from the data processing for PIN or GSO data, respectively. The detail is caused by the fact that we need the actual hk data to produce it, and also we need to reprocess the GSO data with improved gain determination. At present, the background subtraction is accurate typically at 5% level, but observers are strongly recommended to check the model validity with a comparison between light-curves of data and background model. Details of the modeling will be described in a series of documents (reproducibility of PIN background: Suzaku Memo 2006-42, others under preparation).
    • Since the dead-time of HXD data is order 4-7% even for background-dominated sources, users should correct it by use of the `hxddtcor' FTOOL. On the other hand, the background event files of the PIN are already dead-time corrected. Those for the GSO in NOT dead time corrected. See documents such as "7-steps" for detail.
    • Data obtained from 23 March 2006 to 13 May 2006 sometimes suffer additional dead time, clearly seen as dips in raw (i.e. not dead-time corrected) light curve. This is caused by the data transfer saturation within the HXD electronics. The GSO LD was set at a bit lower during these days. The dips are seen in short periods with high data-rates, e.g. after the SAA and/or in low COR. In principle, 'hxddtcor' can handle this phenomena and the spectra shall not be affected. Since the issue is yet to be calibrated, it is better to check if there is a difference in spectra including and excluding these periods. The phenomena may also take place even if your data is not within the specified days. The HXD team is now investigating the recent trends.
  • Common issues:
    • Before guide stars are available for the first time (initial 90 minutes or less), both attitude control and ground attitude determination could be less accurate. Users should check images and light curves carefully.
    • There is a time-dependent misalignment of 30-60 arcsec, which is synchronized with the orbital period of the satellite (96 min). This is not incorporated to calculate X/Y in this version. A correction tool is under development.

  • Spectral Analyis:
    • ARF builder using ray-tracing (`xissimarfgen') is available (Suzaku Memo 2006-39), while RMF generator is not included in this release. Standard RMF and ARF files can be obtained from CALDB page. These ARF files are limited to point source files for standard pointing positions.
    • These standard responses do not include the XIS contamination, which is time, position, and sensor dependent. Please introduce additional absorption model with appropriate column densities for C and O in the case of point source analysis, or use `xissimarfgen' in general. Users can calculate the required C column (C/O=6 in number ratio is assumed at present) with `xiscontamicalc'. For further details on the contamination, see the Technical Description (will be released early 2006 October).
    • The calibraton of the energy scale is underway. XIS gain is accurate to +-0.2% in the iron band and +-5 eV below 1 keV.
    • Effect of the radiation damage is under study now.  In addition, inprecise correction for spatially dependent charge transfer inefficienty (CTI) results in line broadening of order 50 eV (in sigma) at Fe K, and a degradation of quantum detection efficiency of about 5% (as of 2006 April).
    • XIS calibration accuracy becomes worse in window mode or in 2x2 mode.
    • Artificial structure is present in the XIS spectrum in 500-504 ch (1.825-1.84325 keV), which should be discarded from the analysis.
    • Local structures may be present in the XIS spectrum with a level of +-10% in 2-8 keV.
    • The energy response matrices of HXD-PIN have been verified with the Crab observations, for both of the XIS-nominal and HXD-nominal positions. Results are shown in figures. In case of observations performed before 2006 May 24, discrepancies between the data and model are smaller than a few percent in the energy range of 12-40 keV, while they become larger than 3% at >20 keV after the change of one of four PIN-Si bias voltages on 2006 May 29. A newer version of PIN energy response is under development.
    • Users should allow 13% uncertainties at the XIS nominal position and 15% uncertainties at the HXD nominal position in HXD/PIN-XIS cross-normalization. For further details, see Suzaku Memo 2006-40.

  • Timing Analysis:
    • XIS event times are quantized to 8s (see above).  Their absolute accuracy is not calibrated yet.
    • HXD event times have 61 microsec resolution. Absolute timing accuracy is not yet calibrated to this resolution.
    • Barycentric correction software `aebarycen' is released. Calibration using this tool is underway.

  • Imaging Analysis:
    • Exposure map software is not yet included.

Calibration files and related files can be obtained from the Suzaku page in ISAS and GSFC.

ISAS/JAXA Department of High Energy Astrophysics

Last Modified: Tuesday, 24-Apr-2007 19:07:02 JST