BeppoSAX Data Archive :
Data available
The BeppoSAX archive includes the FITS files most commonly used for the
BeppoSAX analysis. This includes data from the following Narrow
Field Instruments (NFI): Low and Medium concentrator spectrometers
(
LECS and
MECS ) and from the
Phoswich detector system (
PSD ).
There are no data available for the High pressure Gas Scintillator Proportional Counter
(
HPGSPC ) or for the
Wide Field Camera .
The NFI data are FITS files produced by the pipelines running at the SAX Data
Center in Italy. The original Final Observation Tape (FOT), containing
the NFI data, distributed to the user is not in the archive.
The BeppoSAX archive is organized by sequence, e.g. data from all NFI
instruments are included the under each sequence.
Data under each sequences is divided in four subdirectories:
raw_event_files, event_files, results and hk_files.
For early processed sequences the raw_event_files directory is missing.
A summary of the data files in the archive and their naming convention
is given in Table 1.
SAXDAS, the basic software for the NFI pipelines, evolved quickly
during the first part of the mission. The archive currectly
contains data obtained from different processing version, e.g.
Rev 0.0 (started 1-Jan-1997), Rev 0.1 (13-Feb-1997), Rev 0.2 (25-Feb-1997),
Rev 1.0 (15-Aug-1997) , Rev 1.1 (3-Sep-1997) and Rev 2 (30-Nov-1998).
The revision number is stored in a file named index.html
under each archived sequence. Data processed with Rev <= 0.2 will be
reprocessed. More details on the different revision is given in the
Cookbook of the BeppoSAX NFI spectral Analysis (HTML
, PS )
LECS and MECS data
The processing for the LECS and MECS, in addition to the housekeeping data,
produces three levels of data: the raw events files, the clean event files
and higher level products.
The raw event files are the reformatted telemetry data in FITS,
where no screening or correction have been applied.
These data need to be processed by the SAXDAS software package before
extracting scientific information.
When extracting these data files from the archive the user have to extract
also the corresponding housekeeping files.
The clean events files are instead data that do not need further re-processing
and can be used to extact high level products like images, lightcurves and
spectra. These data have the coordinates linearized and aspect corrected,
the energy temporal and spatial gain applied and dark earth and SAA excluded.
These files can be directly input into XSELECT or in any other software
package that manipulates event files.
The results directory contains high levels products such
spectra and lightcurves for the pointed source.
These data can be used directly in XSPEC or XRONOS.
PDS data
The archive of the PDS includes an event file and higher level products.
The event file contains all the events detected during an observation.
This is accompany by a serius of GTI files where the time on-off on source
is recorded. The event file and GTI files can be used to extract a spectrum an
a lightcurve using one of the scripts available (e.g.pdproducts)
within SAXDAS.
The higher level products consist of a background subtracted lightcurve
and spectrum, where all the data from both units are combined together.
These files can be directly imported into XSPEC and XRONOS.
The PDS data were included in the pipeline in Feb 1997 (rev 0.2), however
it is recommended to use the PDS data processed after the 15-Aug-1997
with rev 1 processing due to a correction in the PDS backgroung subtraction
method.
HPGSPC and WFC
The HPGSPC data have been included in the pipeline in the December 1998.
Sequences processed earlier do not have the HPGSPC data available
at this time. The public HPGSPC data
can be obtained by requesting the
FOT
from the SDC-SAX (helpdesk@sax.sdc.asi.it).
The WFC data are not part of the archive at this time. The public
WFC data can be obtained by requesting the data from the SDC-SAX (helpdesk@sax.sdc.asi.it).
If you have any questions concerning
BeppoSAX
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