Importing the chain file to Xspec manually

[kchoX14]

• UltraNest version: 3.4.6
• Python version: 3.9.12
• Operating System: Linux Ubuntu 18.04 LTS, kernel v5.7.1-050701-generic

Description

After an Ultranest run, which is the chain file than can be imported outside the Python environment for external processing of the Monte Carlo samples over Xspec directly? Please note that I am using UltraNest over threeML, not BXA.

There are three text (not FITS) files available with parameter samples inside the /chains sub-directory (one of the 5 auto-generated to store the results in):

• equal_weighted_post.txt
• weighted_post.txt
• weighted_post_untransformed.txt.

The last file is the run.txt, which contains the statistical bits.

The /info sub-directory has the posterior summary file (post_summary.csv) and a results.json file.

The sub-directories /extra and /plots are empty.

Another is the points.hdf5 file within the /results sub-directory. Is that the file I should convert to FITS and then use over Xspec?

Requirement Knowing which file is the correct one is essential to me, since I could then try to sample on Xspec to compute the equivalent width of my line model component directly on Xspec. The threeML developers suggested I should ask this question here.

[JohannesBuchner]

The output files are described in https://johannesbuchner.github.io/UltraNest/performance.html#output-files