Roman Catalog Process

This module provides functionality for processing a Roman Telescope multiband catalog to obtain photometric redshifts for cataloged galaxies.

Module API

class roman_photoz.roman_catalog_process.RomanCatalogProcess(config_filename: dict | str = '', model_filename: str = 'roman_model.pkl')

Bases: object

A class to process a Roman Telescope multiband catalog data using rail and lephare.

data

Dictionary to store the processed data.

Type:: dict

flux_cols

List of flux column names.

Type:: list

flux_err_cols

List of flux error column names.

Type:: list

inform_stage

Informer stage for creating the library of SEDs.

Type:: RailStage

estimated

Estimator stage for finding the best fits from the library.

Type:: RailStage

model_filename

Name of the pickle model file to use.

Type:: str

property informer_model_exists

Check if the informer model file exists.

Returns:: True if the model file exists, False otherwise.
Return type:: bool

property informer_model_path

Get the path to the informer model file used.

The path is determined by checking the INFORMER_MODEL_PATH environment variable first, falling back to LEPHAREWORK if not set.

Returns:: The path to the informer model file.
Return type:: str

process(input_filename, output_filename: str | None = None, output_format: str = 'parquet', fit_colname: str = 'segment_{}_flux', fit_err_colname: str = 'segment_{}_flux_err')

Process the Roman catalog data.

Parameters:

input_filename (str) – Name of the input file.
output_filename (str, optional) – Name of the output file. If none is provided (default), the input file will be updated in place.
output_format (str, optional) – Format to save the results. Supported formats are “parquet” (default) and “asdf.”
flux_type (str, optional) – The type of flux to use for fitting. Options are “psf” (default), “kron”, “segment”, or “aperture.”

roman_photoz.roman_catalog_process.main(argv=None): Main function to process Roman catalog data.

Examples

For a quick start, we can use the roman-photoz CLI to create a Roman multiband catalog containing 2000 simulated objects through the roman-photoz-create-simulated-catalog command:

$ roman-photoz-create-simulated-catalog \
   --output-path ./ \
   --output-filename roman_photoz_simulated_catalog.parquet \
   --nobj 2000

Then, use the RomanCatalogProcess class to process the catalog and estimate the redshifts through the roman-photoz command:

$ roman-photoz \
  --input-filename roman_photoz_simulated_catalog.parquet \
  --output-filename roman_photoz_results.parquet \
  --fit-colname segment_{}_flux \
  --fit-err-colname segment_{}_flux_err

Note that if no output filename is provided, as in the following example, the input file will be updated with the results instead:

# run roman-photoz and update the input file with the results
$ roman-photoz \
  --input-filename roman_photoz_simulated_catalog.parquet \
  --fit-colname segment_{}_flux \
  --fit-err-colname segment_{}_flux_err

Additional examples of how to use this module can be found in the Usage section.