Published in

arXiv, 2022

DOI: 10.48550/arxiv.2210.10802

American Astronomical Society, Astrophysical Journal, 1(954), p. 68, 2023

DOI: 10.3847/1538-4357/ace4ba

Links

Tools

Export citation

Search in Google Scholar

Identification of Galaxy–Galaxy Strong Lens Candidates in the DECam Local Volume Exploration Survey Using Machine Learning

Journal article published in 2023 by Erik A. Zaborowski ORCID, Alex Drlica-Wagner ORCID, F. Ashmead, John F. Wu ORCID, Robert Morgan ORCID, Clecio R. Bom ORCID, Anowar J. Shajib ORCID, Simon Birrer ORCID, William Cerny ORCID, L. Buckley-Geer, Elizabeth J. Buckley-Geer ORCID, Burçin Mutlu-Pakdil ORCID, S. J. Gonzalez Lozano ORCID, Peter S. Ferguson ORCID, Karl Glazebrook ORCID and other authors.
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Question mark in circle
Preprint: policy unknown
Question mark in circle
Postprint: policy unknown
Question mark in circle
Published version: policy unknown

Abstract

We perform a search for galaxy-galaxy strong lens systems using a convolutional neural network (CNN) applied to imaging data from the first public data release of the DECam Local Volume Exploration Survey (DELVE), which contains $∼ 520$ million astronomical sources covering $∼ 4,000$ $\mathrm{deg}^2$ of the southern sky to a $5σ$ point-source depth of $g=24.3$, $r=23.9$, $i=23.3$, and $z=22.8$ mag. Following the methodology of similar searches using DECam data, we apply color and magnitude cuts to select a catalog of $∼ 11$ million extended astronomical sources. After scoring with our CNN, the highest scoring 50,000 images were visually inspected and assigned a score on a scale from 0 (definitely not a lens) to 3 (very probable lens). We present a list of 581 strong lens candidates, 562 of which are previously unreported. We categorize our candidates using their human-assigned scores, resulting in 55 Grade A candidates, 149 Grade B candidates, and 377 Grade C candidates. We additionally highlight eight potential quadruply lensed quasars from this sample. Due to the location of our search footprint in the northern Galactic cap ($b > 10$ deg) and southern celestial hemisphere (${\rm Dec.}<0$ deg), our candidate list has little overlap with other existing ground-based searches. Where our search footprint does overlap with other searches, we find a significant number of high-quality candidates which were previously unidentified, indicating a degree of orthogonality in our methodology. We report properties of our candidates including apparent magnitude and Einstein radius estimated from the image separation.