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arXiv · 1805.02427

Star-galaxy classification in the Dark Energy Survey Y1 dataset

I. Sevilla-Noarbe·B. Hoyle·M. J. Marchã·M. T. Soumagnac·K. Bechtol·A. Drlica-Wagner·F. Abdalla·J. Aleksić·C. Avestruz·E. Balbinot·M. Banerji·E. Bertin·C. Bonnett·R. Brunner·M. Carrasco-Kind·A. Choi·T. Giannantonio·E. Kim·O. Lahav·B. Moraes·B. Nord·A. J. Ross·E. S. Rykoff·B. Santiago·E. Sheldon·K. Wei·W. Wester·B. Yanny·T. Abbott·S. Allam·D. Brooks·A. Carnero-Rosell·J. Carretero·C. Cunha·L. da Costa·C. Davis·J. de Vicente·S. Desai·P. Doel·E. Fernandez·B. Flaugher·J. Frieman·J. Garcia-Bellido·E. Gaztanaga·D. Gruen·R. Gruendl·J. Gschwend·G. Gutierrez·D. L. Hollowood·K. Honscheid·D. James·T. Jeltema·D. Kirk·E. Krause·K. Kuehn·T. S. Li·M. Lima·M. A. G. Maia·M. March·R. G. McMahon·F. Menanteau·R. Miquel·R. L. C. Ogando·A. A. Plazas·E. Sanchez·V. Scarpine·R. Schindler·M. Schubnell·M. Smith·R. C. Smith·M. Soares-Santos·F. Sobreira·E. Suchyta·M. E. C. Swanson·G. Tarle·D. Thomas·D. L. Tucker·A. R. Walker
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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 datasets. 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 mis-classification, contamination can be reduced to the O(1%) level by using multi-epoch and infrared information from external datasets. For Milky Way studies the stellar sample can be augmented by ~20% for a given flux limit. Reference catalogs used in this work will be made available upon publication.

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I. Sevilla-Noarbe, B. Hoyle, M. J. Marchã, M. T. Soumagnac, K. Bechtol, A. Drlica-Wagner, F. Abdalla, J. Aleksić, C. Avestruz, E. Balbinot, M. Banerji, E. Bertin, C. Bonnett, R. Brunner, M. Carrasco-Kind, A. Choi, T. Giannantonio, E. Kim, O. Lahav, B. Moraes, B. Nord, A. J. Ross, E. S. Rykoff, B. Santiago, E. Sheldon, K. Wei, W. Wester, B. Yanny, T. Abbott, S. Allam, D. Brooks, A. Carnero-Rosell, J. Carretero, C. Cunha, L. da Costa, C. Davis, J. de Vicente, S. Desai, P. Doel, E. Fernandez, B. Flaugher, J. Frieman, J. Garcia-Bellido, E. Gaztanaga, D. Gruen, R. Gruendl, J. Gschwend, G. Gutierrez, D. L. Hollowood, K. Honscheid, D. James, T. Jeltema, D. Kirk, E. Krause, K. Kuehn, T. S. Li, M. Lima, M. A. G. Maia, M. March, R. G. McMahon, F. Menanteau, R. Miquel, R. L. C. Ogando, A. A. Plazas, E. Sanchez, V. Scarpine, R. Schindler, M. Schubnell, M. Smith, R. C. Smith, M. Soares-Santos, F. Sobreira, E. Suchyta, M. E. C. Swanson, G. Tarle, D. Thomas, D. L. Tucker, A. R. Walker. 2018-05-07. Star-galaxy classification in the Dark Energy Survey Y1 dataset. https://doi.org/10.1093/mnras/sty2579

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