INTEGRAL Science Data Centre

             * * * INTEGRAL OSA 8.0 Software Release * * *

INTEGRAL Off-line Scientific Analysis 8.0

Version 8.0 of the offline scientific analysis (OSA) of INTEGRAL data
is now ready for download at:

with the corresponding documentation available at:

The main focus of this release is the JEM-X instrument with major
improvements in image reconstruction. There are however also minor
changes for the IBIS and SPI instruments. Please note that this OSA
release is the last one for both the Solaris and MacOS/X PowerPC
platforms. Future OSA releases will be on Linux and MacOS/X on Intel.

Please update the calibration database (see below) to the latest
version when upgrading the software to OSA 8.

JEM-X changes
The JEM-X software has been completely revised for the OSA 8 release.
The changes have lead to an important reduction in the systematics
uncertainties on the flux measurements. These improvements are
implemented in the sky image reconstruction tool, which also provides
the reference fluxes for spectral extraction.

JEM-X software now takes into account the measured electronic
efficiencies of both JEM-X units, as well as systematics effects -
like those due to the collimator - which have been redetermined
experimentally. Improved energy calibrations and gain determinations
are achieved by taking into account the effect of detector
temperature. With these changes the ancillary response functions of
each instrument are valid over the whole mission.

SPI changes
The gamma-ray spectrometer SPI had a third detector failure in
February 2009 at the beginning of revolution 776. Despite intensive
effort by the SPI team and MOC, the detector #5 could not be
recovered. SPI is currently working with 16 out of its 19 Germanium
detectors. Following this third detector failure, the SPI software 
has been updated in OSA 8.0 to ignore the dead detectors immediately
after their failures. As for the two previous failures, a new response
file (IRF) has been provided by the NASA/GSFC team to take this change
into account in the SPI analysis. The response file is currently under
testing and will be delivered in an updated version of the IC tree.

The SPI team at the MPE in Garching provided a new software package
for SPI spectral extraction. This is included in OSA 8.0 to give the
users an alternative method for analyzing SPI data. The new script is
called "spimodfit_analysis" and complements the usual analysis using
the "spiros" iterative source extraction method.

IBIS changes
The IBIS/ISGRI energy calibration depends on the total dose received
by the detector pixels in form of charged particles. This is measured
by the INTEGRAL radiation environment monitor (IREM) aboard the
spacecraft. This radiation dose is collected mainly during perigee or
during  strong solar flares. The calibration database include an IREM
dose file that needs  to be updated regularly otherwise the software
performs some interpolation. The interpolation implemented in OSA 8 is
much better than before. To take into account the effects of new solar
flares, we recommend users to update their calibration database
regularly as described below.

In addition, the ISGRI code was cleaned for uninitialized variables
and the analysis scripts were updated for a proper PICsIT analysis in
all situations.

Update of the calibration database

INTEGRAL calibration files are stored in the repository branch for
instrument characteristics (ic/). You can easily upgrade them to the
most recent version by running the following command to download the
latest release to your local directory where the INTEGRAL data are
installed, which is defined in the $REP_BASE_PROD environment
rsync -Lzrtv $REP_BASE_PROD

The "rsync" command is part of most commonly used Linux distributions.
If you run the command repeatedly, only the additional or updated IC
data  files will be downloaded into the $REP_BASE_PROD/ic/ and
$REP_BASE_PROD/idx/ic/ directories.

Next OSA release
The next OSA release is planned for later this year and will include a
much improved source cleaning for ISGRI allowing to create deeper
images than available up to now.

Improved time correlation
A new time correlation has been derived from the beginning of the 
mission up to revolution 791. It is used for the complete reprocessing
of the  data that is going on at the ISDC. These reprocessed archive
will be made available in some months. Until then users requiring
precise timing can download the new time correlation information and
auxiliary information at: