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BeppoSAX U.S. Coordination Facility
[BeppoSAX] [BeppoSAX Email]

BeppoSAX e-mail news n. 10


 
                                                       19 April 2002


Dear BeppoSAX user,


this 10th BeppoSAX "e-mail news" covers the following topics:


1. Identification of a 20 arc sec systematic error in LECS and MECS
sources coordinates estimation

2. Release of SAXDAS 2.3.1 software



1. Correction of a 20 arc sec systematic error in LECS and MECS
coordinates
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The absolute accuracy of LECS and MECS source positioning has been
carefully studied and a 20 arc sec systematic error in both instruments
has been identified.

A detailed discussion on this topic and the instructions on how to
obtain the best LECS and MECS coordinates can be found in a dedicated
BeppoSAX web page:

 http://www.asdc.asi.it/bepposax/coord_correction.html

A specific script, "saxposcor", that corrects LECS and MECS event file
headers has been developed and is available at the mentioned web page.

The headers of all BeppoSAX LECS and MECS event files in the ASDC
archive have been modified to include this coordinate correction and the
improved event files are available on-line since March 12 2002.

Please note that the BeppoSAX data delivered to the HEASARC that have
been produced using old SAXDAS versions (before 2.3.0) do not have the
correction applied. The script "saxposcor" can be downloaded also from
the following web site:

 http://legacy.gsfc.nasa.gov/docs/sax/archive/coordinate_correction.html

After the coordinates correction the absolute pointing accuracy of LECS
and MECS instruments are respectively ~16 and ~17 arc sec at the 90%
confidence level.

2. Release of SAXDAS 2.3.1 software
-----------------------------------

SAXDAS 2.3.1 must be installed under ftools5.1

Modifications with respect to SAXDAS 2.2.1:

 - inclusion of the task "saxposcor" which produces LECS and MECS event
   files with corrected RA and Dec values

 - LECS ROLL ANGLE computation using median value (instead of mean)

 - bug fixed in LECS ESM2 STR_CONF selection

 - minor bugs fixed for Alpha Floating Exception


The SAXDAS 2.3.1 software is available from the ASDC or HEASARC
anonymous ftp service:

 ASDC
 ftp ftp.asdc.asi.it
 Name : anonymous
 cd pub/sax/software/saxdas
 dir

 HEASARC
 ftp legacy.gsfc.nasa.gov
 Name : anonymous
 cd sax/software/saxdas
 dir


Binary versions of SAXDAS 2.3.1 are available for the following
platforms:

 OSF4.0
 Solaris 2.8
 Linux Red Hat 7.0

The binary release is reachable from the ASDC or HEASARC anonymous ftp
service in the directories:

 ASDC:
 pub/sax/software/saxdas/binaries

 HEASARC:
 sax/software/saxdas/binaries

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Please send questions to: asdc_helpdesk@asdc.asi.it

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