INTEGRALPlanckGaiaPOLARCHEOPSEuclidATHENA
HEAVENSFACTCTALOFTSPICAJEM-EUSOXIPEeXTPTheseus
XRISMMAGBOUNDSMARTNet
ISDCCDCI
INTEGRAL Science Data Centre
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                   * * * ISDC-News 09-APR-2009 * * *
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Postdoctoral and PhD research positions in high-energy astrophysics
===================================================================

There are several open postdoctoral and PhD research positions at the
ISDC Data Centre for Astrophysics.
Please refer to the information in the ISDC-News of 10-MAR-2009
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INTEGRAL Off-line Scientific Analysis
=====================================

The next release of the offline scientific analysis (OSA), version 8.0,
is planned for the May time frame. The main focus for this release will
be JEM-X where there will be major improvements in image
reconstruction. In addition, this will be the final release of OSA for
both the Solaris and MacOS/X PowerPC platforms. Future releases will be
on Linux and MacOS/X on Intel.

JEM-X changes
-------------
The JEM-X software is being completely revised for the OSA 8 release.
The changes should lead to a very important reduction in the
systematics uncertainties on the flux measurements. The sky image
reconstruction by the j_ima_iros tool, will become the baseline
flux-extraction method for source spectra and lightcurves production.
It will, however, still be possible to extract spectra from mosaic
images.

j_ima_iros will take 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 short-term temperature variations. With these changes it is
foreseen that a single ancillary response function, valid for both
instruments, could be adequate for 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. The SPI
software has been updated for OSA 8.0 to ignore the dead detectors
after their failures. As for the two previous failures, a new response
file (IRF) will soon be provided by the NASA/GSFC team to take this
change into account in the SPI analysis.

The SPI team at the MPE in Garching provided a new software package for
SPI spectral extraction based on the maximum entropy approach. This
will be included in OSA 8.0 to allow the user to have two independent
ways for SPI analysis: the usual spi_science_analysis using the spiros
method and the new spimodfit_analysis script.
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INTEGRAL Reference Catalogue
============================

A new version of the INTEGRAL General Reference Catalogue is available
at: http://isdc.unige.ch/?Data+catalogs
This version 30 of the catalogue has been updated with all the new
detections, identifications, refined X-ray positions and possible
counterparts up to March 12, 2009. It now includes 1703 sources, 576 of
which detected at least once by IBIS/ISGRI.
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Improved time correlation
=========================

Precise time reconstruction is important for the study of fast
variability from gamma-ray bursts or anomalous X-ray pulsars (AXP) and
for phase determination of pulsars. The time correlation was affected
by several problems like ground station delays and software problems.
Most of these problems have been understood and corrected. A number of
time correlation records were also eliminated. A new time correlation
has been derived from the beginning of the mission. It will be used for
a complete reprocessing of the data that has started  at the ISDC.
Users requiring precise timing can already download the new time
correlation information and auxiliary information at:
http://isdc.unige.ch/?Soft+download
[Make sure you give write access before untarring and set the files
back to read only afterwards.]

The reprocessed data will also include an offset of the SPI
anti-coincidence shield (ACS) timetags to align the ACS timing with
that of the other instruments. Note however that this is already taken
into account since a long time in the generation of all the ACS
gamma-ray burst data products.
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IBIS/ISGRI energy calibration
=============================

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. Even if the interpolation implemented in
OSA 8 will be even better it cannot take new solar flares into account.
We therefore recommend users to update their calibration database
regularly following the method described below.
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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 variable:

rsync -Lzrtv isdcarc.unige.ch::arc/FTP/arc_distr/ic_tree/prod/ $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.
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