Star–galaxy classification in the Dark Energy Survey Y1 data set. Issue 4 (21st September 2018)

• Record Type: Journal Article
• Authors: Sevilla-Noarbe, I; Hoyle, B; Marchã, M J; Soumagnac, M T; Bechtol, K; Drlica-Wagner, A; Abdalla, F; Aleksić, J; Avestruz, C; Balbinot, E; Banerji, M; Bertin, E; Bonnett, C; Brunner, R; Carrasco-Kind, M; Choi, A; Giannantonio, T; Kim, E; Lahav, O; Moraes, B; Nord, B; Ross, A J; Rykoff, E S; Santiago, B; Sheldon, E; Wei, K; Wester, W; Yanny, B; Abbott, T; Allam, S; Brooks, D; Carnero-Rosell, A; Carretero, J; Cunha, C; da Costa, L; Davis, C; de Vicente, J; Desai, S; Doel, P; Fernandez, E; Flaugher, B; Frieman, J; Garcia-Bellido, J; Gaztanaga, E; Gruen, D; Gruendl, R; Gschwend, J; Gutierrez, G; Hollowood, D L; Honscheid, K; James, D; Jeltema, T; Kirk, D; Krause, E; Kuehn, K; Li, T S; Lima, M; Maia, M A G; March, M; McMahon, R G; Menanteau, F; Miquel, R; Ogando, R L C; Plazas, A A; Sanchez, E; Scarpine, V; Schindler, R; Schubnell, M; Smith, M; Smith, R C; Soares-Santos, M; Sobreira, F; Suchyta, E; Swanson, M E C; Tarle, G; Thomas, D; Tucker, D L; Walker, A R; (The DES Collaboration), ;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 481:Issue 4(2018)
• Page Start: 5451
• Page End: 5469
• Publication Date: 2018-09-21
• Subjects: Methods: data analysis -- Methods: statistical -- Techniques: photometric; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty2579
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We perform a comparison of different approaches to star–galaxy classification using the broad-band photometric data from Year 1 of the Dark Energy Survey. This is done by performing a wide range of tests with and without external 'truth' information, which can be ported to other similar data sets. We make a broad evaluation of the performance of the classifiers in two science cases with DES data that are most affected by this systematic effect: large-scale structure and Milky Way studies. In general, even though the default morphological classifiers used for DES Y1 cosmology studies are sufficient to maintain a low level of systematic contamination from stellar misclassification, contamination can be reduced to the O(1 per cent) level by using multi-epoch and infrared information from external data sets. For Milky Way studies, the stellar sample can be augmented by ${\sim }20{{\ \rm per\ cent}}$ for a given flux limit. Reference catalogues used in this work are available at http://des.ncsa.illinois.edu/releases/y1a1 .