BeppoSAX e-mail news n. 8

                                                   18 April 2000
Dear BeppoSAX user,

this is the eighth BeppoSAX "e-mail news" message and covers the
following topics:

        1. Release of SAXDAS 2.1.1  software
        2. Release of improved calibrations



1. Release of SAXDAS 2.1.1  software
------------------------------------

SAXDAS 2.1.1 has to be installed under ftools5.0

Modifications with respect to SAXDAS 2.0:

-  foting is Y2K compliant.
   HPGSPC DIR002, DIR003 and DIR004 modes are implemented.
   PDS duplicate packets are disregarded.

-  pdproducts now generate a merged background light curve file
   (_bck.lc)

-  Full support for HPGSPC.
   A new background strategy is implemented in hpproducts.
   Dark Earth data are used instead of data from off-source regions.
   Therefore the HPGSPC collimator is kept on source for the
   whole observation, doubling the on-source exposure time.

-  the program LEMAT (to generate LECS .arf and .rmf files),
   including the latest ray-tracing code and the latest LECS
   calibrations, is included in the release.

-  Bug fixed in EVELIN. This resulted in no spatial gain correction
   in LECS linearized event files (maybe relevant for sources at off-axis
   angles > 8 arcmin, on axis source are basically not affected).

-  Several minor bugs have been corrected.




The SAXDAS 2.1.1 software is available from the SDC anonymous ftp service:
 ftp www.sdc.asi.it
 Name : anonymous
 cd pub/sax/software/saxdas
 dir


Binary version of SAXDAS 2.1.1 are available for the
following platforms:
OSF4.0
Solaris 2.7
Linux Red Hat 6.1

The binary release is reachable in the directory

 cd pub/sax/software/saxdas/binaries
 dir




2. Release of improved calibrations
-----------------------------------

-  The LECS response is now calibrated up to 10 keV. Redistribution
   matrix and effective area can be generated using the program LEMAT,
   included in the SAXDAS 2.1.1. distribution. They can also be retrieved
   from the SDC anonymous ftp.
   The LECS response is now (slightly) dependent
   on the source count rate. This is due to the modelling of double
   events (events which occur very soon after each other are detected
   at their sum-energy). Double event modelling has
   (almost) no measurable effect below ~ 30 cts/sec while only above
   ~60 cts/sec the correction is noticable. So for the
   vast majority of the sources this effect is completely unimportant,
   only for *very* bright sources (Crab, Cyg X-2) this effect is
   important and a response should be generated appropiate for the
   count rate.

   In summary:
   LECS count rate less then 30 cts/sec: use standard rmf
   LECS count rate higher than 60 cts/sec: for optimal modeling one
   should use the matrix generated for this count rate
   LECS count rate between 30 and 60: the effects is probably not
   important, but it depends on the shape of the spectrum
   (and the signal to noise (i.e. EXPOSURE)), so if you want to be
   safe use the appropriate matrix

   The files in the SDC anonymous ftp were generated for a source with
   a count rate of 0.5 cts/sec,

-  A new HPGSPC effective area file is available (HPGSPC_jul99.arf).
   This MUST be used for observations performed AFTER JULY 1999.
   For observations performed before July 1999, the old
   HPGSPC_oct98.arf file MUST be used.

The new LECS and HPGSPC  .arf and .rmf response files are available from the
SDC anonymous ftp in the

 /pub/sax/cal/responses/99_12

directory.

MECS and PDS response files have not been modified and can be
retrieved from the

 /pub/sax/cal/responses/98_11

directory.

-  New LECS background files are now available. The total sky and
non X-ray backgroud (dark Earth) exposures are now of 1.0 and 1.2 Msec
respectively.

Background event files and .pha files are available in the

 /pub/sax/cal/bgd/99_12
and
 /pub/sax/cal/bgd/98_11

directories.


***********************************************************************
The BeppoSAX software, calibration and documentation is also available
from the mirror of the SDC  anonymous ftp service based at HEASARC:

ftp heasarc.gsfc.nasa.gov

 Name : anonymous
 cd sax/software/saxdas               SAXDAS 2.1.1

 cd sax/cal/responses                 .arf and .rmf response files

 cd sax/cal/bgd                       Background event and .pha files

***********************************************************************
Please consult the README files before retriving the  new calibrations.
***********************************************************************




Fabrizio Fiore, Francesca Tamburelli & Paolo Giommi
BeppoSAX Science Data Center



------------------BeppoSAX SDC useful addresses and numbers----------------

WWW home page     http://www.sdc.asi.it/
anonymous ftp     www.sdc.asi.it
phone             +39 06 40796307 (M.E. Pennisi, SDC secretary)
fax               +39 06 40793855, +39 06 40796291
e-mail            helpdesk@sax.sdc.asi.it
p-mail address    BeppoSAX Science Data Center
                  ASI
                  c/o Nuova Telespazio
                  via Corcolle 19
                  00131 Roma
                  Italy
how to reach us   http://www.sdc.asi.it/howreach.html

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