Galaxy Surveys cheatsheet

Tiny package containing useful parameters from main galaxy surveys (with units).

The goal of this project is to provide a Python library with minimal dependencies that centralises galaxy survey properties with adequate reference. Such information tends to be scattered in many places or is often copy/pasted without all of the relevant information like units or sources.

WORK IN PROGRESS: the API is still unstable, expect backward incompatibilities

Getting started | API | Contributing | Acknowledgements | License

Getting started

1. Install the latest version of the library

   pip install -U galcheat

2. Run the demo = print the available surveys and associated filters

   python -m galcheat
   # or
   galcheat

API

# The list of available surveys
from galcheat import available_surveys

# Getter methods to retrieve a Survey of a Filter dataclass
from galcheat import get_survey, get_filter

Rubin = get_survey("Rubin")
u_band = get_filter("u", "Rubin")
# which is a proxy for
u_band = Rubin.get_filter("u")

# Get the list of available filters
Rubin.available_filters

# or as a dictionary with all `Filter` objects
Rubin.get_filters()

# Both Survey and Filter classes have physical attributes
Rubin.mirror_diameter
u_band.exposure_time

# Filters are also attributes of a Survey
Rubin.filters.u.exposure_time  # same attribute as above

# These attributes are Astropy Quantity objects with units
fwhm = u_band.psf_fwhm
# The value in the original units is obtained as
fwhm.value
# or it can be converted to other units
import astropy.units as u
fwhm.to_value(u.arcmin)

Contributing

A number is missing? An error slipped into the files? A survey is not included in the list and you can provide the relevant information or some of it?

Head over to the contributing guidelines to learn how to participate into making this library more robust and complete.

Acknowledgements

This project was started in the context of the BlendingToolKit (BTK) and has initialy received contributions from (alphabetical order)

• Alexandre Boucaud
• Rémy Joseph
• Ismael Mendoza
• Maxime Paillassa
• Thomas Sainrat

License

This project is developed under an MIT-license. See LICENSE file for more information.