A Python pipeline for photometric redshift estimation, designed to work with large astronomical catalogs. This repository provides tools to download a DESI DR9 galaxy catalog and split it into HEALPix-based tiles for efficient spatial indexing.

The project currently implements two preprocessing steps:

1. Download the DESI DR9 catalog from an external URL.
2. Split the catalog into smaller FITS files per HEALPix pixel (coarse resolution) and adds a column with a finer HEALPix index.

• Python 3.6 or higher
• Required packages:
  • numpy
  • astropy
  • healpy
  • pyyaml
  • requests
  • tqdm

Install them with:

pip install numpy astropy healpy pyyaml requests tqdm