Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-23T19:10:58.439Z Has data issue: false hasContentIssue false

Cooperative photometric redshift estimation

Published online by Cambridge University Press:  30 May 2017

S. Cavuoti
Affiliation:
INAF - Astronomical Observatory of Capodimonte, via Moiariello 16, I-80131 Napoli, Italy
C. Tortora
Affiliation:
Kapteyn Astronomical Institute, Univ. of Groningen, P.O. Box 800, 9700 AV Groningen, the Netherlands
M. Brescia
Affiliation:
INAF - Astronomical Observatory of Capodimonte, via Moiariello 16, I-80131 Napoli, Italy
G. Longo
Affiliation:
Department of Physics, University Federico II, Via Cinthia 6, I-80126 Napoli, Italy
M. Radovich
Affiliation:
INAF - Astronomical Observatory of Padua, vicolo dell’Osservatorio 5, I-35122 Padova, Italy
N. R. Napolitano
Affiliation:
INAF - Astronomical Observatory of Capodimonte, via Moiariello 16, I-80131 Napoli, Italy
V. Amaro
Affiliation:
Department of Physics, University Federico II, Via Cinthia 6, I-80126 Napoli, Italy
C. Vellucci
Affiliation:
DIETI, University of Naples Federico II, Via Claudio, 21 I-80125 Napoli, Italy
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In the modern galaxy surveys photometric redshifts play a central role in a broad range of studies, from gravitational lensing and dark matter distribution to galaxy evolution. Using a dataset of ~ 25,000 galaxies from the second data release of the Kilo Degree Survey (KiDS) we obtain photometric redshifts with five different methods: (i) Random forest, (ii) Multi Layer Perceptron with Quasi Newton Algorithm, (iii) Multi Layer Perceptron with an optimization network based on the Levenberg-Marquardt learning rule, (iv) the Bayesian Photometric Redshift model (or BPZ) and (v) a classical SED template fitting procedure (Le Phare). We show how SED fitting techniques could provide useful information on the galaxy spectral type which can be used to improve the capability of machine learning methods constraining systematic errors and reduce the occurrence of catastrophic outliers. We use such classification to train specialized regression estimators, by demonstrating that such hybrid approach, involving SED fitting and machine learning in a single collaborative framework, is capable to improve the overall prediction accuracy of photometric redshifts.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2017 

References

Ahn, C. P., Alexandroff, R., Allende Prieto, C., et al. 2012, ApJS, 203, 21 CrossRefGoogle Scholar
Benitez, N., 2000, ApJ, 536, 571 CrossRefGoogle Scholar
Bertin, E. & Arnouts, S., 1996, A&AS, 117, 393 Google Scholar
Breiman, L., 2001, Machine Learning, Springer Eds., 45, 1, 2532 Google Scholar
Brescia, M., Cavuoti, S., Longo, G., & De Stefano, V., 2015, A&A, 568, A126.Google Scholar
Brescia, M., Cavuoti, S., Longo, G., et al., 2014, PASP, 126, 942, 743797 Google Scholar
Brescia, M., Cavuoti, S., D’Abrusco, R., Mercurio, A., & Longo, G., 2013, ApJ, 772, 140 Google Scholar
Byrd, R. H., Nocedal, J., & Schnabel, R. B., 1994, Mathematical Programming, 63, 129156 Google Scholar
Cavuoti, S., et al., 2017, MNRAS 465 (2): 19591973.Google Scholar
Cavuoti, S., Brescia, M., Tortora, C., et al. 2015, MNRAS, 452, 3, 31003105 CrossRefGoogle Scholar
Cavuoti, S., et al., 2015, Experimental Astronomy, Springer, Vol. 39, Issue 1, 4571 Google Scholar
Cavuoti, S., Brescia, M., Longo, G., & Mercurio, A., 2012, A&A, 546, 13 Google Scholar
de Jong, J. T. A., Verdoes Kleijn, G. A., Boxhoorn, D. R., et al., 2015, A&A, 582, A62 Google Scholar
Fotopoulou, S., et al. submitted to MNRASGoogle Scholar
Ilbert, O., Arnouts, S., McCracken, H. J., et al., 2006, A&A, 457, 841 Google Scholar
Liske, J., Baldry, I. K., Driver, S. P., et al., 2015, MNRAS, 452, 2, 20872126 Google Scholar
Nocedal, J. & Wright, S. J., 2006, Numerical Optimization, 2nd Edition. Springer Google Scholar
Tortora, C., La Barbera, F., Napolitano, N. R., et al., 2016, MNRAS, 457, 3, 28452854 Google Scholar