Time delay lens modelling challenge
| Autor: | Daniel Gilman, Tommaso Treu, G. Despali, Christopher D. Fassnacht, Jonathan P. Coles, Frederic Courbin, Anupreeta More, Hyungsuk Tak, Matthew W. Auger, Hum Chand, Matteo Frigo, Philip J. Marshall, M. Millon, Dominique Sluse, A. Galan, L. Van de Vyvere, Geoff C. F. Chen, Joshua Yao-Yu Lin, Da Xu, Anowar J. Shajib, Philipp Denzel, Xuheng Ding, Ji Won Park, Simona Vegetti, Simon Birrer, Stefan Hilbert, Liliya L. R. Williams, Vivien Bonvin, Prasenjit Saha, S. R. Kumar |
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| Rok vydání: | 2021 |
| Předmět: |
degeneracies
profiles Point spread function Accuracy and precision Cosmology and Nongalactic Astrophysics (astro-ph.CO) Point source Test data generation internal structure FOS: Physical sciences central image Kinematics 01 natural sciences Measure (mathematics) law.invention hubble constant law evolution 0103 physical sciences early-type galaxies Instrumentation and Methods for Astrophysics (astro-ph.IM) 010303 astronomy & astrophysics Physics 010308 nuclear & particles physics gravitational lensing: strong Astronomy and Astrophysics methods: data analysis Astrophysics - Astrophysics of Galaxies Lens (optics) Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) cosmology: observations impact precision constraints Astrophysics - Instrumentation and Methods for Astrophysics Completeness (statistics) Algorithm Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stab484 |
| Popis: | In recent years, breakthroughs in methods and data have enabled gravitational time delays to emerge as a very powerful tool to measure the Hubble constant $H_0$. However, published state-of-the-art analyses require of order 1 year of expert investigator time and up to a million hours of computing time per system. Furthermore, as precision improves, it is crucial to identify and mitigate systematic uncertainties. With this time delay lens modelling challenge we aim to assess the level of precision and accuracy of the modelling techniques that are currently fast enough to handle of order 50 lenses, via the blind analysis of simulated datasets. The results in Rung 1 and Rung 2 show that methods that use only the point source positions tend to have lower precision ($10 - 20\%$) while remaining accurate. In Rung 2, the methods that exploit the full information of the imaging and kinematic datasets can recover $H_0$ within the target accuracy ($ |A| < 2\%$) and precision ($< 6\%$ per system), even in the presence of poorly known point spread function and complex source morphology. A post-unblinding analysis of Rung 3 showed the numerical precision of the ray-traced cosmological simulations to be insufficient to test lens modelling methodology at the percent level, making the results difficult to interpret. A new challenge with improved simulations is needed to make further progress in the investigation of systematic uncertainties. For completeness, we present the Rung 3 results in an appendix, and use them to discuss various approaches to mitigating against similar subtle data generation effects in future blind challenges. 23 pages, 12 figures, 6 tables, MNRAS accepted |
| Databáze: | OpenAIRE |
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