Host Galaxy Identification for Supernova Surveys
Abstract
Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Therefore, reliable identification of host galaxies is essential for cosmology and SN science. We simulate SN events and their locations within their host galaxies to develop and test methods for matching SNe to their hosts. We use both real and simulated galaxy catalog data from the Advanced Camera for Surveys General Catalog and MICECATv2.0, respectively. We also incorporate "hostless" SNe residing in undetected faint hosts into our analysis, with an assumed hostless rate of 5%. Our fully automated algorithm is run on catalog data and matches SNe to their hosts with 91% accuracy. We find that including a machine learning component, run after the initial matching algorithm, improves the accuracy (purity) of the matching to 97% with a 2% cost in efficiency (true positive rate). Although the exact results are dependent on the details of the survey and the galaxy catalogs used, the method of identifying host galaxies we outline here can be applied to any transient survey.
Cite
@article{arxiv.1604.06138,
title = {Host Galaxy Identification for Supernova Surveys},
author = {Ravi R. Gupta and Steve Kuhlmann and Eve Kovacs and Harold Spinka and Richard Kessler and Daniel A. Goldstein and Camille Liotine and Katarzyna Pomian and Chris B. D'Andrea and Mark Sullivan and Jorge Carretero and Francisco J. Castander and Robert C. Nichol and David A. Finley and John A. Fischer and Ryan J. Foley and Alex G. Kim and Andreas Papadopoulos and Masao Sako and Daniel M. Scolnic and Mathew Smith and Brad E. Tucker and Syed Uddin and Rachel C. Wolf and Fang Yuan and Tim M. C. Abbott and Filipe B. Abdalla and Aurelien Benoit-Levy and Emmanuel Bertin and David Brooks and Aurelio Carnero Rosell and Matias Carrasco Kind and Carlos E. Cunha and Luiz N. da Costa and Shantanu Desai and Peter Doel and Tim F. Eifler and August E. Evrard and Brenna Flaugher and Pablo Fosalba and Enrique Gaztanaga and Daniel Gruen and Robert Gruendl and David J. James and Kyler Kuehn and Nikolay Kuropatkin and Marcio A. G. Maia and Jennifer L. Marshall and Ramon Miquel and Andres A. Plazas and A. Kathy Romer and Eusebio Sanchez and Michael Schubnell and Ignacio Sevilla-Noarbe and Flavia Sobreira and Eric Suchyta and Molly E. C. Swanson and Gregory Tarle and Alistair R. Walker and William Wester},
journal= {arXiv preprint arXiv:1604.06138},
year = {2016}
}
Comments
22 pages, 18 figures; Accepted by AJ, revised to incorporate referee comments