What is a "standard" CIAO installation?
The CIAO threads assume that all of the "standard" CIAO components have been downloaded and installed: tools, Sherpa, the Scripts Package, and the CALDB.
![[NOTE]](../imgs/note.png)
The prism package was removed in CIAO 4.14.
If you have installed a customized version of CIAO, it is possible that some of the analysis tasks will fail due to a missing package. Similarly, the scripts may contain a dependency on any of the other standard components, and will fail if one is missing.
| Installation | Area | Packages |
|---|---|---|
| conda | executables | ciao, ciao-contrib, ds9, marx, sherpa |
| CALDB | caldb, caldb_main, acis_bkg_evt, hrc_bkg_evt | |
| ciao-install | executables | core, graphics, tools, obsvis, sherpa |
| CALDB | CALDB_main, CALDB_acis_bkgrnd, CALDB_hrc_bkgrnd |
You do not need all these packages to use CIAO; in particular the CALDB packages are no always needed (and you can use the download_obsid_caldb script to download a subset of the CALDB just for the Chandra data you wish to a analyze).