An automated method for finding the most distant quasars

Fuente: arXiv
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Main Authors: Lenz, Lena, Mortlock, Daniel J., Leistedt, Boris, Barnett, Rhys, Hewett, Paul C.
Format: Preprint
Published: 2024
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author Lenz, Lena
Mortlock, Daniel J.
Leistedt, Boris
Barnett, Rhys
Hewett, Paul C.
author_facet Lenz, Lena
Mortlock, Daniel J.
Leistedt, Boris
Barnett, Rhys
Hewett, Paul C.
contents Upcoming surveys such as Euclid, the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) and the Nancy Grace Roman Telescope (Roman) will detect hundreds of high-redshift (z > 7) quasars, but distinguishing them from the billions of other sources in these catalogues represents a significant data analysis challenge. We address this problem by extending existing selection methods by using both i) Bayesian model comparison on measured fluxes and ii) a likelihood-based goodness-of-fit test on images, which are then combined using the F_beta statistic (where beta is a parameter which can be tuned to prioritise completeness). The result is an automated, reproduceable and objective high-redshift quasar selection pipeline. We test this on both simulations and real data from the cross-matched Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) catalogues. On this cross-matched dataset we achieve an area under the curve (AUC) score of up to 0.81 and an F_3 score of up to 0.79; or, if the completeness is fixed to be 0.9, then we can obtain an efficiency of 0.15. This is sufficient to be applied to the Euclid, LSST and Roman data when available.
format Preprint
id arxiv_https___arxiv_org_abs_2408_12770
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle An automated method for finding the most distant quasars
Lenz, Lena
Mortlock, Daniel J.
Leistedt, Boris
Barnett, Rhys
Hewett, Paul C.
Instrumentation and Methods for Astrophysics
Astrophysics of Galaxies
Upcoming surveys such as Euclid, the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) and the Nancy Grace Roman Telescope (Roman) will detect hundreds of high-redshift (z > 7) quasars, but distinguishing them from the billions of other sources in these catalogues represents a significant data analysis challenge. We address this problem by extending existing selection methods by using both i) Bayesian model comparison on measured fluxes and ii) a likelihood-based goodness-of-fit test on images, which are then combined using the F_beta statistic (where beta is a parameter which can be tuned to prioritise completeness). The result is an automated, reproduceable and objective high-redshift quasar selection pipeline. We test this on both simulations and real data from the cross-matched Sloan Digital Sky Survey (SDSS) and UKIRT Infrared Deep Sky Survey (UKIDSS) catalogues. On this cross-matched dataset we achieve an area under the curve (AUC) score of up to 0.81 and an F_3 score of up to 0.79; or, if the completeness is fixed to be 0.9, then we can obtain an efficiency of 0.15. This is sufficient to be applied to the Euclid, LSST and Roman data when available.
title An automated method for finding the most distant quasars
topic Instrumentation and Methods for Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2408.12770