PSFGAN: a generative adversarial network system for separating quasar point sources and host galaxy light
| Autor: | Ce Zhang, Hantian Zhang, Barthelemy Launet, Yiru Chen, Dominic Stark, Kevin Schawinski, Michael Koss, Lia F. Sartori, Anna K. Weigel, M. Dennis Turp |
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| Přispěvatelé: | Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) |
| Rok vydání: | 2018 |
| Předmět: |
Point spread function
Active galactic nucleus Point source media_common.quotation_subject FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences data analysis techniques: image processing quasars: general [methods] 0103 physical sciences 010303 astronomy & astrophysics ComputingMilieux_MISCELLANEOUS Astrophysics::Galaxy Astrophysics media_common Parametric statistics Physics [PHYS]Physics [physics] 010308 nuclear & particles physics Astronomy and Astrophysics Quasar Astrophysics - Astrophysics of Galaxies Galaxy Space and Planetary Science Sky Physics - Data Analysis Statistics and Probability Astrophysics of Galaxies (astro-ph.GA) [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Host (network) Data Analysis Statistics and Probability (physics.data-an) |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 477 (2) Monthly Notices of the Royal Astronomical Society Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2018, 477 (2), pp.2513-2527. ⟨10.1093/mnras/sty764⟩ |
| ISSN: | 0035-8711 1365-2966 |
| DOI: | 10.48550/arxiv.1803.08925 |
| Popis: | The study of unobscured active galactic nuclei (AGN) and quasars depends on the reliable decomposition of the light from the AGN point source and the extended host galaxy light. The problem is typically approached using parametric fitting routines using separate models for the host galaxy and the point spread function (PSF). We present a new approach using a Generative Adversarial Network (GAN) trained on galaxy images. We test the method using Sloan Digital Sky Survey (SDSS) r-band images with artificial AGN point sources added which are then removed using the GAN and with parametric methods using GALFIT. When the AGN point source PS is more than twice as bright as the host galaxy, we find that our method, PSFGAN, can recover PS and host galaxy magnitudes with smaller systematic error and a lower average scatter ($49\%$). PSFGAN is more tolerant to poor knowledge of the PSF than parametric methods. Our tests show that PSFGAN is robust against a broadening in the PSF width of $\pm 50\%$ if it is trained on multiple PSF's. We demonstrate that while a matched training set does improve performance, we can still subtract point sources using a PSFGAN trained on non-astronomical images. While initial training is computationally expensive, evaluating PSFGAN on data is more than $40$ times faster than GALFIT fitting two components. Finally, PSFGAN it is more robust and easy to use than parametric methods as it requires no input parameters. Comment: 17 pages, 18 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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