Matching CIAO and CALDB Versions
CIAO 3.4 requires CALDB 3.3.0 or higher to operate properly.
CALDB 3.4.0 and higher should not be used unless you are running CIAO 3.4 or CIAO 4.0.
Are your versions mismatched? Time to update CIAO and CALDB!
11 Nov 2008
These are the webpages relative to the CIAO 3.4 release (18 December 2006). They are no longer actively updated, however the CXC will continue limited support of CIAO 3.4 for the near future.
CIAO 3.4 users should check the CALDB 3 website for compatible calibration updates.
Science Threads for CIAO 3.4
The following threads are designed to work with processing versions later than R4CU5UPD8 or DS 6.0.0. Nearly all Chandra data available satisfies this criterion. Please visit the Chandra Data Archive to find the most up-to-date processing of an observation.
A list of all the threads on one page.
Beginners should start here. The Introductory threads provide an overview of the main components (GUI applications, plotting) and concepts (the Data Model, filtering) in the CIAO data analysis software.
When Chandra data goes through Standard Data Processing (SDP), the most recently available calibration is applied to it. Since this calibration is continuously being improved, one should check whether there are currently newer files available. Similarly, some science decisions are made during SDP; every user has the option to reprocess the data with different parameters.
In order to perform absolute timing analysis on a dataset, a barycenter correction must first be applied to the data. One may then create lightcurves and phase-binned spectra to look for variability in the source. These threads also provide information on working with data taken in the ACIS continuous clocking (CC) mode.
The Imaging threads cover a wide range of topics that include source detection, creating exposure maps and normalized images, and calculating image statistics. How to create color images for publication is addressed, as well as merging data from multiple observations.
If new calibration has been applied to the event file, the grating spectrum should be re-extracted as well. It is then possible to build grating response files (gARF, gRMF) in order to model and fit the data in Sherpa.
A list of threads that use S-Lang, the CIAO Scripting Language, to automate a variety of tasks.
Links to the datasets used in the threads.
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