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2 topics: new CTI table and ASCA databases



ASCA Users,


[1] New CTI table

The SIS team has released a new CTI calibration file,

    sisph2pi_110397.fits

which is now available from

    ftp://legacy.gsfc.nasa.gov/caldb/data/asca/sis/bcf/sisph2pi_110397.fits

This is a refinement of the old version (sisph2pi_290297.fits) using Cas A
calibration observations as well as the background Ni line data.  The Dotani
et al article in the next issue of the ASCA Newsletter will contain the
detailed comparison of the two versions.  As is shown in this article,
a noticeable improvement may result for SIS data taken in or after 1995,
when the PI values are rederived using this new calibration file.

It can be applied to any SIS Bright and Bright2 mode event files, including
the screened *.evt files and unscreened *.unf files found in the ASCA archive.
To apply the new calibration, use the Ftool 'sispi', and give the new
calibration file name as the second input to the program (the first input
is the name of the event file to be updated).

This file is also used by the Ftool 'sisrmg' in creating the SIS response
matrix.  To use this, the calibration file should be copied to the
refdata/sisdata area of the Ftools, and the phtopi parameter be changed
to reflect the new file name.

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[2] ASCA databases in W3browse

We are in the process of consolidating 3 existing catalogs, ASCAPUBLIC
(for the archival data), ASCALOG (the observation log), and ASCADISTRIB
(the processing and data distribution) into a single ASCAMASTER catalog.
Please be advised that we plan to phase out the above 3 catalogs over
the next few months. However, ASCAO (the proposal database) will remain
unchanged, as will ASCASIS (the SIS source catalog).

Please try using the new ASCAMASTER catalog, and let us
(ascahelp@athena.gsfc.nasa.gov) know if you experience any problems.