Crowded Cluster Cores: Algorithms for Deblending in Dark Energy Survey Images

Abstract

Deep optical images are often crowded with overlapping objects. This is especially true in the cores of galaxy clusters, where images of dozens of galaxies may lie atop one another. Accurate measurements of cluster properties require deblending algorithms designed to automatically extract a list of individual objects and decide what fraction of the light in each pixel comes from each object. We present new software called the Gradient And INterpolation based deblender (GAIN) as a secondary deblender to improve deblending the images of cluster cores. This software relies on using image intensity gradient and using an image interpolation technique usually used to correct flawed terrestrial digital images. We test this software on Dark Energy Survey coadd images. GAIN helps extracting unbiased photometry measurement for blended sources. It also helps improving detection completeness while introducing only a modest amount of spurious detections. For example, when applied to deep images simulated with high level of deblending difficulties, this software improves detection completeness from 91% to 97% for sources above the 10? limiting magnitude at 25.3 mag. We expect this software to be a useful tool for cluster population measurements.

Published on PASP

References in corpus (3)

• CANDELS Multiwavelength catalogs: Source Identification and Photometry in the CANDELS UKIDSS Ultra-Deep Survey Field
• The Blanco Cosmology Survey: Data Acquisition, Processing, Calibration, Quality Diagnostics and Data Release
• GALAPAGOS: From Pixels to Parameters

Cited by in corpus (12)

• Weak lensing for precision cosmology
• ProFound: Source Extraction and Application to Modern Survey Data
• Deblending and Classifying Astronomical Sources with Mask R-CNN Deep Learning
• SCARLET: Source separation in multi-band images by Constrained Matrix Factorization
• Galaxies in X-ray Selected Clusters and Groups in Dark Energy Survey Data I: Stellar Mass Growth of Bright Central Galaxies Since z~1.2
• Deblending galaxy superpositions with branched generative adversarial networks
• Probing galaxy evolution in massive clusters using ACT and DES: splashback as a cosmic clock
• Measurement of the B-band Galaxy Luminosity Function with Approximate Bayesian Computation
• The PAU Survey: Measurement of Narrow-band galaxy properties with Approximate Bayesian Computation
• Comparing Dark Energy Survey and HST-CLASH observations of the galaxy cluster RXC J2248.7-4431: implications for stellar mass versus dark matter
• M32 Analogs? A Population of Massive Ultra Compact Dwarf and Compact Elliptical Galaxies in intermediate redshift CLASH Clusters
• Dark Energy Survey Year 1 Results: Photometric Data Set for Cosmology