The scientific analysis pipelines are made of independent components for each of the INTEGRAL instruments. It is possible to independently execute just one of these components, i.e., to analyze the data from one instrument only.
Taking advantage of the scientific analysis similarities, tasks/levels common to all instruments are identified, and designated with a unique name. This makes a system more user friendly, avoiding confusion between different instruments. A given name refers to similar tasks and conversely. The only exception is IMA2 level, which combines different tasks for OMC, JEM-X and IBIS.
The definition of common scientific analysis levels also enforces similarities in the Architectural Design of the instrument specific scientific analysis. However, the scientific analysis is partly instrument specific. Some tasks/levels do not exist for all instruments, and the task order also differs. These different levels are described below.
COR - Data Correction IBIS, SPI, JEM-X, OMC
corrects science data for instrumental effects, such as energy and position corrections.
POIN - Pointing DefinitionSPI
defines a number of time periods during which the S/C attitude can be considered as constant for SPI analysis (e.g., a slew can be split into a number of periods) and extracts the spacecraft
attitude information from the input group. Stores the results in a pointing file for further
use.
GTI - Good Time Handling IBIS, SPI, JEM-X, OMC
generates, selects, and merges Good Time Intervals to produce a unique GTI which is to be
used for selecting good events. GTI can be used to exclude times of TM stream gaps, high
background, instrument anomalous behavior, etc. The net observing time is also computed
in this step.
DEAD - Dead and Live Times IBIS, SPI, JEM-X
computes dead time (i.e., the time during which the instrument was not capable to register
the incoming photons for different reasons) within the good time interval.
BIN_I - Event Binning for Imaging IBIS, SPI, JEM-X
defines the energy bins to be used for imaging, selects good events within the GTI, and
creates event arrays.
BKG, BKG_I, BKG_S - Background Model Generation IBIS, SPI, JEM-X
derives estimated background from models, either for imaging analysis (BKG I), for spectral
analysis (BKG S), or for the general case (BKG). Corrects IBIS shadowgrams for background.
CAT, CAT_I, CAT_S - Catalog Source Selection IBIS, SPI, JEM-X
selects a list of known sources from the ISDC reference catalog, or from previous analyses,
and creates a source data structure, containing source location and expected flux values.
IMA - Image Reconstruction IBIS, SPI, JEM-X, OMC
generates sky images and searches for significant sources. If sources are detected, a new
source data structure is created, including a copy of the input source data and the newly
derived source properties, such as source positions and fluxes.
IMA2 - PICsIT Image Reconstruction IBIS
For IBIS, ISGRI and PICsIT image analysis are split into two levels.
IMA2 - JEM-X Mosaic creation JEM-X
At this level the mosaic image of JEM-X observations along with the summary list of all
found sources are created.
IMA2 - OMC Summary List OMC
At this level the summary list of the derived magnitudes for all OMC shots is created.
BIN_S - Event Binning for Spectral Analysis IBIS, SPI, JEM-X
defines the energy bins to be used for spectral analysis, selects good events within the GTI,
and creates detector spectra.
SPE - Spectra Extraction IBIS, JEM-X
extracts spectra for individual sources, and produces the specific response files (ARFs) needed
for spectral fitting with the XSPEC package.
BIN_T - Create Detector Light Curves JEM-X
defines the energy bins to be used for light curves analysis,
LCR - Extract Source Light Curves IBIS,JEM-X
produces light curves for individual sources.