Overview of Process

Overview of Process#

For my work, my main goal was to identify XRBs within spiral galaxies, categorize them by the masses of their donor stars as low-mass, intermediate-mass, and high-mass XRBs (LMXBs, IMXBs, and HMXBs respectively), and analyze their abundances, environments, etc. The procedures I use to accomplish this are theoretically simple, but may be technically complex depending on the nuances of the particular galaxy of interest. Below I’ve provided a template .ipynb of my process (NOTE: this is currently out of date, but I’ll update it soon) that works out of Google Collab (though it requires a few additional custom scripts, which are found in the pyfiles of my GitHub XRBID repository). That code will not run straight out of the box on your computer without a lot of modification, but can be used to get an idea of what I’ll be doing for the rest of this guide. In general, the process I use can be broken down into these basic steps:

  1. Select a galaxy (or galaxies) of interest;

  2. Obtain the CXO X-ray Data from the Chandra Source Catalog (CSC);

  3. If necessary, obtain the optical imaging from the HST from the Hubble Legacy Archive (HLA) or MAST either directly or through an HLA query;

  4. If necessary, combine the HST images into a single mosaic using AstroDrizzle (this step isn’t strictly required, but may be useful for a variety of reasons);

  5. Identify point sources in HST image(s);

  6. Calculate the photometric corrections on each HST field/image;

  7. Perform astrometric corrections on the X-ray coordinates to align them to the optical image;

  8. Identify candidate optical counterparts for each X-ray source;

  9. Identify supernova remnants, background galaxies, and foreground stars among the optical counterparts;

  10. Extract the photometry of candidate donor stars and host star clusters, including photometric corrections;

  11. Create a color-magnitude diagram of candidate donor stars or color-color diagrams of candidate host star clusters to estimate the masses of the XRB donor stars; and

  12. Perform any other analysis necessary on the XRB populations.

Contents