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Title: The Photometric LSST Astronomical Time-series Classification Challenge PLAsTiCC: Selection of a Performance Metric for Classification Probabilities Balancing Diverse Science Goals

Abstract

Classification of transient and variable light curves is an essential step in using astronomical observations to develop an understanding of the underlying physical processes from which they arise. However, upcoming deep photometric surveys, including the Large Synoptic Survey Telescope (LSST), will produce a deluge of low signal-to-noise data for which traditional type estimation procedures are inappropriate. Probabilistic classification is more appropriate for such data but is incompatible with the traditional metrics used on deterministic classifications. Furthermore, large survey collaborations like LSST intend to use the resulting classification probabilities for diverse science objectives, indicating a need for a metric that balances a variety of goals. We describe the process used to develop an optimal performance metric for an open classification challenge that seeks to identify probabilistic classifiers that can serve many scientific interests. The Photometric LSST Astronomical Time-series Classification Challenge (PLASTICC) aims to identify promising techniques for obtaining classification probabilities of transient and variable objects by engaging a broader community beyond astronomy. Using mock classification probability submissions emulating realistically complex archetypes of those anticipated of PLASTICC, we compare the sensitivity of two metrics of classification probabilities under various weighting schemes, finding that both yield results that are qualitatively consistent with intuitivemore » notions of classification performance. We thus choose as a metric for PLASTICC a weighted modification of the cross-entropy because it can be meaningfully interpreted in terms of information content. Finally, we propose extensions of our methodology to ever more complex challenge goals and suggest some guiding principles for approaching the choice of a metric of probabilistic data products.« less

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3];  [4]; ORCiD logo [5];  [6]; ORCiD logo [7]; ORCiD logo [8]; ORCiD logo [6]; ORCiD logo [9]; ORCiD logo [10]; ORCiD logo [11]; ORCiD logo [12]; ORCiD logo [13]; ORCiD logo [14]; ORCiD logo [3]; ORCiD logo [15]; ORCiD logo [16]; ORCiD logo [17]; ORCiD logo [4] more »; ORCiD logo [18]; ORCiD logo [5] « less
  1. German Centre of Cosmological Lensing, Ruhr-Universität Bochum, Universitätsstraße 150, Bochum, Germany; New York Univ., New York, NY (United States). Center for Cosmology and Particle Physics; New York Univ., New York, NY (United States). Dept. of Physics
  2. Univ. of Toronto, Toronto, ON, Canada. Dept. of Astronomy and Astrophysics; Univ. of Toronto, Toronto, ON, Canada. Dunlap Institute for Astronomy and Astrophysics
  3. University College London, Dorking, United Kingdom. Mullard Space Science Lab, Dept. of Space and Climate Physics
  4. Univ. of Toronto, Toronto, ON, Canada. Dunlap Institute for Astronomy and Astrophysics
  5. Stockholm University, AlbaNova, Stockholm, Sweden. The Oskar Klein Centre for Cosmoparticle Physics, Dept. of Physics
  6. Rutgers, the State University of New Jersey, Piscataway, NJ (United States)
  7. Univ. of Pittsburgh, Pittsburgh, PA (United States); Departamento de Física Teórica y del Cosmos, Universidad de Granada, Granada, Spain
  8. Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000 Clermont-Ferrand, France
  9. Univ. of California, Santa Cruz, Santa Cruz, CA (United States)
  10. KICP, Chicago, IL (United States)
  11. African Institute for Mathematical Sciences, 6 Melrose Road, Muizenberg, 7945, South Africa; South African Radio Astronomy Observatory, The Park, Park Road, Pinelands, Cape Town 7405, South Africa
  12. California Institute of Technology, Pasadena, CA (United States). Div. of Physics, Mathematics, and Astronomy; California Institute of Technology, Pasadena, CA (United States). Center for Data Driven Discovery
  13. Institute of Astronomy and Kavli Institute for Cosmology, Madingley Road, Cambridge, United Kingdom; Univ. of Cambridge, Wilberforce Road, Cambridge, United Kingdom. Statistical Laboratory, DPMMS
  14. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
  15. Institute of Astronomy and Kavli Institute for Cosmology, Madingley Road, Cambridge, United Kingdom
  16. Space Telescope Science Institute, Baltimore, MD (United States)
  17. Stockholm University, AlbaNova, Stockholm, Sweden. The Oskar Klein Centre for Cosmoparticle Physics, Dept. of Physics; Department of Physics and Astronomy, University College London, Gower Street, London, United Kingdom
  18. Univ. of California Berkeley, Berkeley, CA (United States). Berkeley Center for Cosmological Physics
Publication Date:
Research Org.:
Rutgers Univ., Piscataway, NJ (United States); Univ. of California, Oakland, CA (United States); Stanford Univ., CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); Swedish Research Council (SRC); Ajax Foundation; Marie Sklodowska-Curie; ERC
Contributing Org.:
LSST Dark Energy Science Collaboration; LSST Transients and Variable Stars Science Collaboration
OSTI Identifier:
1802229
Grant/Contract Number:  
SC0011636; AC02-05CH11231; AC02-76SF00515; AST-1517237; Dnr 2016-06012; AST-0909182; AST-1313422; AST-1413600; AST-1518308; 839090; 306478-CosmicDawn
Resource Type:
Accepted Manuscript
Journal Name:
The Astronomical Journal (Online)
Additional Journal Information:
Journal Name: The Astronomical Journal (Online); Journal Volume: 158; Journal Issue: 5; Journal ID: ISSN 1538-3881
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; astronomy & astrophysics; data analysis; statistical methods; variables; supernovae; surveys; photometric

Citation Formats

Malz, A. I., Hložek, R., Allam, T., Bahmanyar, A., Biswas, R., Dai, M., Galbany, L., Ishida, E. E. O., Jha, S. W., Jones, D. O., Kessler, R., Lochner, M., Mahabal, A. A., Mandel, K. S., Martínez-Galarza, J. R., McEwen, J. D., Muthukrishna, D., Narayan, G., Peiris, H., Peters, C. M., Ponder, K., and Setzer, C. N. The Photometric LSST Astronomical Time-series Classification Challenge PLAsTiCC: Selection of a Performance Metric for Classification Probabilities Balancing Diverse Science Goals. United States: N. p., 2019. Web. doi:10.3847/1538-3881/ab3a2f.
Malz, A. I., Hložek, R., Allam, T., Bahmanyar, A., Biswas, R., Dai, M., Galbany, L., Ishida, E. E. O., Jha, S. W., Jones, D. O., Kessler, R., Lochner, M., Mahabal, A. A., Mandel, K. S., Martínez-Galarza, J. R., McEwen, J. D., Muthukrishna, D., Narayan, G., Peiris, H., Peters, C. M., Ponder, K., & Setzer, C. N. The Photometric LSST Astronomical Time-series Classification Challenge PLAsTiCC: Selection of a Performance Metric for Classification Probabilities Balancing Diverse Science Goals. United States. https://doi.org/10.3847/1538-3881/ab3a2f
Malz, A. I., Hložek, R., Allam, T., Bahmanyar, A., Biswas, R., Dai, M., Galbany, L., Ishida, E. E. O., Jha, S. W., Jones, D. O., Kessler, R., Lochner, M., Mahabal, A. A., Mandel, K. S., Martínez-Galarza, J. R., McEwen, J. D., Muthukrishna, D., Narayan, G., Peiris, H., Peters, C. M., Ponder, K., and Setzer, C. N. Thu . "The Photometric LSST Astronomical Time-series Classification Challenge PLAsTiCC: Selection of a Performance Metric for Classification Probabilities Balancing Diverse Science Goals". United States. https://doi.org/10.3847/1538-3881/ab3a2f. https://www.osti.gov/servlets/purl/1802229.
@article{osti_1802229,
title = {The Photometric LSST Astronomical Time-series Classification Challenge PLAsTiCC: Selection of a Performance Metric for Classification Probabilities Balancing Diverse Science Goals},
author = {Malz, A. I. and Hložek, R. and Allam, T. and Bahmanyar, A. and Biswas, R. and Dai, M. and Galbany, L. and Ishida, E. E. O. and Jha, S. W. and Jones, D. O. and Kessler, R. and Lochner, M. and Mahabal, A. A. and Mandel, K. S. and Martínez-Galarza, J. R. and McEwen, J. D. and Muthukrishna, D. and Narayan, G. and Peiris, H. and Peters, C. M. and Ponder, K. and Setzer, C. N.},
abstractNote = {Classification of transient and variable light curves is an essential step in using astronomical observations to develop an understanding of the underlying physical processes from which they arise. However, upcoming deep photometric surveys, including the Large Synoptic Survey Telescope (LSST), will produce a deluge of low signal-to-noise data for which traditional type estimation procedures are inappropriate. Probabilistic classification is more appropriate for such data but is incompatible with the traditional metrics used on deterministic classifications. Furthermore, large survey collaborations like LSST intend to use the resulting classification probabilities for diverse science objectives, indicating a need for a metric that balances a variety of goals. We describe the process used to develop an optimal performance metric for an open classification challenge that seeks to identify probabilistic classifiers that can serve many scientific interests. The Photometric LSST Astronomical Time-series Classification Challenge (PLASTICC) aims to identify promising techniques for obtaining classification probabilities of transient and variable objects by engaging a broader community beyond astronomy. Using mock classification probability submissions emulating realistically complex archetypes of those anticipated of PLASTICC, we compare the sensitivity of two metrics of classification probabilities under various weighting schemes, finding that both yield results that are qualitatively consistent with intuitive notions of classification performance. We thus choose as a metric for PLASTICC a weighted modification of the cross-entropy because it can be meaningfully interpreted in terms of information content. Finally, we propose extensions of our methodology to ever more complex challenge goals and suggest some guiding principles for approaching the choice of a metric of probabilistic data products.},
doi = {10.3847/1538-3881/ab3a2f},
journal = {The Astronomical Journal (Online)},
number = 5,
volume = 158,
place = {United States},
year = {Thu Oct 10 00:00:00 EDT 2019},
month = {Thu Oct 10 00:00:00 EDT 2019}
}

Works referenced in this record:

K2 variable catalogue – II. Machine learning classification of variable stars and eclipsing binaries in K2 fields 0–4
journal, December 2015

  • Armstrong, D. J.; Kirk, J.; Lam, K. W. F.
  • Monthly Notices of the Royal Astronomical Society, Vol. 456, Issue 2
  • DOI: 10.1093/mnras/stv2836

The Third Gravitational Lensing Accuracy Testing (GREAT3) Challenge Handbook
text, January 2013


Separation of pulsar signals from noise using supervised machine learning algorithms
journal, April 2018


Statistical classification techniques for photometric supernova typing: Statistical methods for photometric typing
journal, April 2011


Detecting Solar-like Oscillations in Red Giants with Deep Learning
journal, May 2018


Kernel PCA for type Ia supernovae photometric classification
text, January 2012


Detecting Solar-like Oscillations in Red Giants with Deep Learning
text, January 2018


Photometric Supernova Classification With Machine Learning
text, January 2016


Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning
journal, December 2016

  • Möller, A.; Ruhlmann-Kleider, V.; Leloup, C.
  • Journal of Cosmology and Astroparticle Physics, Vol. 2016, Issue 12
  • DOI: 10.1088/1475-7516/2016/12/008

K ‐Corrections and Extinction Corrections for Type Ia Supernovae
journal, August 2002

  • Nugent, Peter; Kim, Alex; Perlmutter, Saul
  • Publications of the Astronomical Society of the Pacific, Vol. 114, Issue 798
  • DOI: 10.1086/341707

Observing Dark Worlds: A crowdsourcing experiment for dark matter mapping
journal, July 2014


Observation of a Rapidly Pulsating Radio Source
journal, February 1968

  • Hewish, A.; Bell, S. J.; Pilkington, J. D. H.
  • Nature, Vol. 217, Issue 5130
  • DOI: 10.1038/217709a0

Measuring photometric redshifts using galaxy images and Deep Neural Networks
journal, July 2016


Results from the Supernova Photometric Classification Challenge
journal, December 2010

  • Kessler, Richard; Bassett, Bruce; Belov, Pavel
  • Publications of the Astronomical Society of the Pacific, Vol. 122, Issue 898
  • DOI: 10.1086/657607

Gravitational Lensing Accuracy Testing 2010 (GREAT10) Challenge Handbook
journal, September 2011

  • Kitching, Thomas; Amara, Adam; Gill, Mandeep
  • The Annals of Applied Statistics, Vol. 5, Issue 3
  • DOI: 10.1214/11-AOAS484

zBEAMS: a unified solution for supernova cosmology with redshift uncertainties
journal, October 2017

  • Roberts, Ethan; Lochner, Michelle; Fonseca, José
  • Journal of Cosmology and Astroparticle Physics, Vol. 2017, Issue 10
  • DOI: 10.1088/1475-7516/2017/10/036

A Hybrid Ensemble Learning Approach to Star-Galaxy Classification
text, January 2015


K-corrections and Extinction Corrections for Type Ia Supernovae
text, January 2002


Classification and unsupervised clustering of LIGO data with Deep Transfer Learning
journal, May 2018


Bayesian High-Redshift Quasar Classification from Optical and Mid-Ir Photometry
journal, August 2015

  • Richards, Gordon T.; Myers, Adam D.; Peters, Christina M.
  • The Astrophysical Journal Supplement Series, Vol. 219, Issue 2
  • DOI: 10.1088/0067-0049/219/2/39

Forecasting Solar Flares Using Magnetogram-based Predictors and Machine Learning
text, January 2018


Automated probabilistic classification of transients and variables
journal, March 2008

  • Mahabal, A.; Djorgovski, S. G.; Turmon, M.
  • Astronomische Nachrichten, Vol. 329, Issue 3
  • DOI: 10.1002/asna.200710943

Ensemble modeling of CMEs using the WSA-ENLIL+Cone model
text, January 2015


Automating Discovery and Classification of Transients and Variable Stars in the Synoptic Survey Era
journal, November 2012

  • Bloom, J. S.; Richards, J. W.; Nugent, P. E.
  • Publications of the Astronomical Society of the Pacific, Vol. 124, Issue 921
  • DOI: 10.1086/668468

Star–galaxy classification using deep convolutional neural networks
journal, October 2016

  • Kim, Edward J.; Brunner, Robert J.
  • Monthly Notices of the Royal Astronomical Society, Vol. 464, Issue 4
  • DOI: 10.1093/mnras/stw2672

The Third Gravitational Lensing Accuracy Testing (Great3) Challenge Handbook
journal, April 2014

  • Mandelbaum, Rachel; Rowe, Barnaby; Bosch, James
  • The Astrophysical Journal Supplement Series, Vol. 212, Issue 1
  • DOI: 10.1088/0067-0049/212/1/5

Machine Learning-based Brokers for Real-time Classification of the LSST Alert Stream
text, January 2018


Detecting Quasars in Large-Scale Astronomical Surveys
conference, December 2010

  • Gieseke, Fabian; Polsterer, Kai Lars; Thom, Andreas
  • 2010 International Conference on Machine Learning and Applications (ICMLA), 2010 Ninth International Conference on Machine Learning and Applications
  • DOI: 10.1109/ICMLA.2010.59

Machine-learning selection of optical transients in the Subaru/Hyper Suprime-Cam survey
journal, October 2016

  • Morii, Mikio; Ikeda, Shiro; Tominaga, Nozomu
  • Publications of the Astronomical Society of Japan, Vol. 68, Issue 6
  • DOI: 10.1093/pasj/psw096

Rotation-invariant convolutional neural networks for galaxy morphology prediction
journal, April 2015

  • Dieleman, Sander; Willett, Kyle W.; Dambre, Joni
  • Monthly Notices of the Royal Astronomical Society, Vol. 450, Issue 2
  • DOI: 10.1093/mnras/stv632

Forecasting Solar Flares Using Magnetogram-based Predictors and Machine Learning
journal, January 2018


Photometric Supernova Classification with Machine Learning
journal, August 2016

  • Lochner, Michelle; McEwen, Jason D.; Peiris, Hiranya V.
  • The Astrophysical Journal Supplement Series, Vol. 225, Issue 2
  • DOI: 10.3847/0067-0049/225/2/31

SiFTO: An Empirical Method for Fitting SN Ia Light Curves
journal, July 2008

  • Conley, A.; Sullivan, M.; Hsiao, E. Y.
  • The Astrophysical Journal, Vol. 681, Issue 1
  • DOI: 10.1086/588518

PHOTOMETRIC TYPE Ia SUPERNOVA CANDIDATES FROM THE THREE-YEAR SDSS-II SN SURVEY DATA
journal, August 2011


Detection of bars in galaxies using a deep convolutional neural network
journal, March 2018

  • Abraham, Sheelu; Aniyan, A. K.; Kembhavi, Ajit K.
  • Monthly Notices of the Royal Astronomical Society, Vol. 477, Issue 1
  • DOI: 10.1093/mnras/sty627

Deep learning classification in asteroseismology
journal, May 2017

  • Hon, Marc; Stello, Dennis; Yu, Jie
  • Monthly Notices of the Royal Astronomical Society, Vol. 469, Issue 4
  • DOI: 10.1093/mnras/stx1174

Approximating Photo- z PDFs for Large Surveys
journal, June 2018


CONSTRUCTION OF A CALIBRATED PROBABILISTIC CLASSIFICATION CATALOG: APPLICATION TO 50k VARIABLE SOURCES IN THE ALL-SKY AUTOMATED SURVEY
journal, December 2012

  • Richards, Joseph W.; Starr, Dan L.; Miller, Adam A.
  • The Astrophysical Journal Supplement Series, Vol. 203, Issue 2
  • DOI: 10.1088/0067-0049/203/2/32

Ensemble Modeling of CMEs Using the WSA–ENLIL+Cone Model
journal, May 2015


Unity: Confronting Supernova Cosmology’S Statistical and Systematic Uncertainties in a Unified Bayesian Framework
journal, November 2015


Kernel PCA for Type Ia supernovae photometric classification
journal, January 2013

  • Ishida, E. E. O.; de Souza, R. S.
  • Monthly Notices of the Royal Astronomical Society, Vol. 430, Issue 1
  • DOI: 10.1093/mnras/sts650

Gravity Spy: integrating advanced LIGO detector characterization, machine learning, and citizen science
journal, February 2017


Measuring Dark Energy Properties with Photometrically Classified Pan-STARRS Supernovae. II. Cosmological Parameters
journal, April 2018


Results from the Supernova Photometric Classification Challenge
text, January 2010


Matplotlib: A 2D Graphics Environment
journal, January 2007


Deep-HiTS: Rotation Invariant Convolutional Neural Network for Transient Detection
journal, February 2017

  • Cabrera-Vives, Guillermo; Reyes, Ignacio; Förster, Francisco
  • The Astrophysical Journal, Vol. 836, Issue 1
  • DOI: 10.3847/1538-4357/836/1/97

Python for Scientific Computing
journal, January 2007


Machine-learning Selection of Optical Transients in Subaru/Hyper Suprime-Cam Survey
text, January 2016


The NumPy Array: A Structure for Efficient Numerical Computation
journal, March 2011

  • van der Walt, Stéfan; Colbert, S. Chris; Varoquaux, Gaël
  • Computing in Science & Engineering, Vol. 13, Issue 2
  • DOI: 10.1109/MCSE.2011.37

Deep learning classification in asteroseismology using an improved neural network: results on 15 000 Kepler red giants and applications to K2 and TESS data
journal, February 2018

  • Hon, Marc; Stello, Dennis; Yu, Jie
  • Monthly Notices of the Royal Astronomical Society, Vol. 476, Issue 3
  • DOI: 10.1093/mnras/sty483

Machine-learning-based Brokers for Real-time Classification of the LSST Alert Stream
journal, May 2018

  • Narayan, Gautham; Zaidi, Tayeb; Soraisam, Monika D.
  • The Astrophysical Journal Supplement Series, Vol. 236, Issue 1
  • DOI: 10.3847/1538-4365/aab781

Radio Galaxy Zoo: Claran – a deep learning classifier for radio morphologies
journal, October 2018

  • Wu, Chen; Wong, Oiwei Ivy; Rudnick, Lawrence
  • Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 1
  • DOI: 10.1093/mnras/sty2646

A hybrid ensemble learning approach to star–galaxy classification
journal, August 2015

  • Kim, Edward J.; Brunner, Robert J.; Carrasco Kind, Matias
  • Monthly Notices of the Royal Astronomical Society, Vol. 453, Issue 1
  • DOI: 10.1093/mnras/stv1608