dr-guangtou / damascus

Massive Galaxies Clusters in DECaLS

DAMASCUS - DecAls MASsive Clusters Using central galaxieS

• This repo includes the codes, scripts, and Jupyter notebooks that help study massive galaxies in the DECaLS survey footprint with the help of the DESI spectroscopic data.

  • Most of the actual analysis will be done on NERSC's Cori supercomputer with the help of the legacyhalos package developed by John Moustakas. It will also make heavy use the legacypipe and tractor photometric engine developed by Dustin Lang.
  • Here the codes are mainly for preparing the sample and post-processing the legacyhalos outputs for scientific analysis.
  • The legacyhalos pipeline will also provide us the cutout images of galaxies. Damascus will try to include codes to perform other photometric analysis on them.

• Right now, this repo also includes codes and notebooks for carrying out DESi service tasks for:

  1. The Bright Galaxies (BGS) working group.
  2. The Cluster, Cross-Correlation, and Small-Scale Clustering (C3) working group.

• This repo will also try to include photometric comparison of galaxies between HSC and LegacySurvey images.

  • Jia-Xuan Li (李嘉轩; Princeton) has worked extensively on this and has summarized the results in this paper. His Kuaizi repo includes all the codes and scripts for the analysis. There will be some overlap.

Useful links:

• DECaLS (The Dark Energy Camera Legacy Survey)

• DECaLS is a component of the DESI Legacy Imaging Surveys

  • Overview of the DESI Legacy Imaging Surveys

• legacyhalos - Code and papers for a multi-faceted study of the baryonic content of dark matter halos in Legacy Survey imaging by John Moustakas

• legacypipe - Image reduction pipeline for the DESI Legacy Imaging Surveys, using the Tractor framework

• obiwan - Inject artificial sources and rerun the pipeline to understand systematics