The HEASARC is running nominally. If you are trying to download a lot of data, please consider using the AWS cloud copy of most HEASARC data. As an alternative to locally installing HEASoft, SciServer is an online platform which has the software installed and data available when you login.
select obscat
Syntax:
This creates a reduced catalogue, based on a selection expression. The original catalogue is moved to a new name. If the original catalogue was xsel_s1.cat, then it will be moved to xsel_s1_v.cat. The new obscat will have the name xsel_s1.cat, and will be automatically loaded for you. So choose and show obscat will now act on this catalogue. N.B. this command does not read in any data, it only produces a reduced catalogue. You will now have to choose data from it.
xsel > select obscat <cat_sel>
Example:
xsel > select obscat "datamode=='BRIGHT'"
This makes a reduced obscat containing only files for which the datamode is BRIGHT.