Host Galaxy Identification for Supernova Surveys
Creators: name: Gupta, Ravi R.
name: Kuhlmann, Steve
name: Kovacs, Eve
name: Spinka, Harold
name: Kessler, Richard
name: Goldstein, Daniel A.
name: Liotine, Camille
name: Pomian, Katarzyna
name: D'Andrea, Chris B.
name: Sullivan, Mark
name: Carretero, Jorge
name: Castander, Francisco J.
name: Nichol, Robert C.
name: Finley, David A.
name: Fischer, John A.
name: Foley, Ryan J.
name: Kim, Alex G.
name: Papadopoulos, Andreas
name: Sako, Masao
name: Scolnic, Daniel M.
name: Smith, Mathew
name: Tucker, Brad E.
name: Uddin, Syed
name: Wolf, Rachel C.
name: Yuan, Fang
name: Abbott, Tim M. C.
name: Abdalla, Filipe B.
name: Benoit-Levy, Aurelien
name: Bertin, Emmanuel
name: Brooks, David
name: Rosell, Aurelio Carnero
name: Kind, Matias Carrasco
name: Cunha, Carlos E.
name: da Costa, Luiz N.
name: Desai, Shantanu
name: Doel, Peter
name: Eifler, Tim F.
name: Evrard, August E.
name: Flaugher, Brenna
name: Fosalba, Pablo
name: Gaztanaga, Enrique
name: Gruen, Daniel
name: Gruendl, Robert
name: James, David J.
name: Kuehn, Kyler
name: Kuropatkin, Nikolay
name: Maia, Marcio A. G.
name: Marshall, Jennifer L.
name: Miquel, Ramon
name: Plazas, Andres A.
name: Romer, A. Kathy
name: Sanchez, Eusebio
name: Schubnell, Michael
name: Sevilla-Noarbe, Ignacio
name: Sobreira, Flavia
name: Suchyta, Eric
name: Swanson, Molly E. C.
name: Tarle, Gregory
name: Walker, Alistair R.
name: Wester, William
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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.
description: 22 pages, 18 figures; Accepted by AJ, revised to incorporate referee comments