Strong Lens Time Delay Challenge: I. Experimental Design
Gregory Dobler,Gregory Dobler,Christopher D. Fassnacht,Tommaso Treu,Phillip J. Marshall,Kai Liao,Alireza Hojjati,Eric V. Linder,Nicholas Rumbaugh +8 more
TLDR
An overview of the challenge is given, a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms are introduced, and the results of TDC0 are presented.Abstract:
The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming \emph{Large Synoptic Survey Telescope} (LSST) will monitor $\sim10^3$ strongly lensed quasars. In an effort to assess the present capabilities of the community to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a "Time Delay Challenge" (TDC). The challenge is organized as a set of "ladders," each containing a group of simulated datasets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' datasets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of datasets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, December 1, 2013. The TDC1 deadline was July 1 2014. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness-of-fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper II.read more
Citations
More filters
Journal ArticleDOI
H0LiCOW - V. New COSMOGRAIL time delays of HE 0435-1223: H0 to 3.8 per cent precision from strong lensing in a flat ΛCDM model
Vivien Bonvin,Frederic Courbin,Sherry H. Suyu,Sherry H. Suyu,Sherry H. Suyu,Philip J. Marshall,Cristian E. Rusu,Dominique Sluse,M. Tewes,Kenneth C. Wong,Thomas E. Collett,Christopher D. Fassnacht,Tommaso Treu,Matthew W. Auger,Stefan Hilbert,Léon V. E. Koopmans,G. Meylan,N. Rumbaugh,Alessandro Sonnenfeld,Chiara Spiniello +19 more
TL;DR: In this article, a new measurement of the Hubble Constant H-0 and other cosmological parameters based on the joint analysis of three multiply imaged quasar systems with measured gravitational time delays is presented.
Journal ArticleDOI
H0LiCOW – I. H0 Lenses in COSMOGRAIL's wellspring: program overview
Sherry H. Suyu,Sherry H. Suyu,Sherry H. Suyu,Vivien Bonvin,Frederic Courbin,Christopher D. Fassnacht,Cristian E. Rusu,Dominique Sluse,Tommaso Treu,Kenneth C. Wong,Matthew W. Auger,Xuheng Ding,Xuheng Ding,Stefan Hilbert,Philip J. Marshall,N. Rumbaugh,Alessandro Sonnenfeld,Alessandro Sonnenfeld,Alessandro Sonnenfeld,M. Tewes,O. Tihhonova,Adriano Agnello,Roger Blandford,Geoff C. F. Chen,Geoff C. F. Chen,Thomas E. Collett,Léon V. E. Koopmans,Kai Liao,Georges Meylan,Chiara Spiniello +29 more
TL;DR: The H0LiCOW (H-0 Lenses in COSMOGRAIL's Wellspring) project as mentioned in this paper is a program that aims to measure H-0 with <3.5 per cent uncertainty from five lens systems (B1608+ 656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805).
Journal ArticleDOI
TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
Simon Birrer,Anowar J. Shajib,A. Galan,M. Millon,Tommaso Treu,Adriano Agnello,Matthew W. Auger,Geoff C. F. Chen,Lise Christensen,Thomas E. Collett,Frederic Courbin,Christopher D. Fassnacht,Christopher D. Fassnacht,Léon V. E. Koopmans,Philip J. Marshall,Ji Won Park,Cristian E. Rusu,Dominique Sluse,Chiara Spiniello,Chiara Spiniello,Sherry H. Suyu,Sherry H. Suyu,Sherry H. Suyu,Sebastian Wagner-Carena,Kenneth C. Wong,Matteo Barnabè,Adam S. Bolton,Oliver Czoske,Xuheng Ding,Joshua A. Frieman,Joshua A. Frieman,L. Van de Vyvere +31 more
TL;DR: In this article, a hierarchical Bayesian approach was proposed to estimate the mass-sheet transform (MST) with respect to stellar kinematics, which is based on a family of mass models.
Journal ArticleDOI
A SHARP view of H0LiCOW: H 0 from three time-delay gravitational lens systems with adaptive optics imaging
Geoff C. F. Chen,Christopher D. Fassnacht,Sherry H. Suyu,Sherry H. Suyu,Sherry H. Suyu,Cristian E. Rusu,James H. H. Chan,Kenneth C. Wong,Kenneth C. Wong,Matthew W. Auger,Stefan Hilbert,Vivien Bonvin,Simon Birrer,M. Millon,Léon V. E. Koopmans,D. Lagattuta,John McKean,Simona Vegetti,Frederic Courbin,Xuheng Ding,Aleksi Halkola,Inh Jee,Anowar J. Shajib,Dominique Sluse,Alessandro Sonnenfeld,Alessandro Sonnenfeld,Tommaso Treu +26 more
TL;DR: In this paper, an adaptive optics (AO) imaging from the Keck Telescope, obtained as part of the SHARP AO effort, with Hubble Space Telescope (HST) imaging, velocity dispersion measurements, and a description of the line-of-sight mass distribution was used to build an accurate and precise lens mass model.
Journal ArticleDOI
Time Delay Cosmography
Tommaso Treu,Philip J. Marshall +1 more
TL;DR: Gravitational time delays, observed in strong lens systems where the variable background source is multiply-imaged by a massive galaxy in the foreground, provide direct measurements of cosmological distance that are very complementary to other cosmographic probes as discussed by the authors.
References
More filters
Journal ArticleDOI
On the possibility of determining Hubble's parameter and the masses of galaxies from the gravitational lens effect
Journal ArticleDOI
0957 + 561 A, B: twin quasistellar objects or gravitational lens?
TL;DR: Difficulties arise in describing these two QSOs as two distinct objects and the possibility that they are two images of the same object formed by a gravitational lens is discussed.
Journal ArticleDOI
Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations
TL;DR: In this article, a sample of optical light curves for 100 quasars, 70 of which have black hole mass estimates, was used to estimate the characteristic timescale and amplitude of flux variations; their approach is not affected by biases introduced from discrete sampling effects.
Journal ArticleDOI
The Shear Testing Programme – I. Weak lensing analysis of simulated ground-based observations
Catherine Heymans,Ludovic Van Waerbeke,D. J. Bacon,Joel Bergé,Gary Bernstein,Emmanuel Bertin,Sarah Bridle,Michael L. Brown,Douglas Clowe,H. Dahle,Thomas Erben,Meghan E. Gray,M. Hetterscheidt,Henk Hoekstra,P. Hudelot,Mike Jarvis,Konrad Kuijken,Vera Margoniner,Richard Massey,Yannick Mellier,R. Nakajima,Alexandre Refregier,Jason Rhodes,Tim Schrabback,David Wittman +24 more
TL;DR: The Shear Testing Programme (STEP) is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys as discussed by the authors.
Journal ArticleDOI
Dissecting the Gravitational lens B1608+656. II. Precision Measurements of the Hubble Constant, Spatial Curvature, and the Dark Energy Equation of State
Sherry H. Suyu,Philip J. Marshall,Philip J. Marshall,Matthew W. Auger,Matthew W. Auger,Stefan Hilbert,Roger Blandford,Léon V. E. Koopmans,Christopher D. Fassnacht,Tommaso Treu,Tommaso Treu +10 more
TL;DR: In this article, a Bayesian analysis of the strong gravitational lens system B1608+656 is presented, incorporating new, deep Hubble Space Telescope (HST) observations, a new velocity-dispersion measurement of 260 ± 15 km s-1 for the primary lens galaxy, and an updated study of the lens' environment.
Related Papers (5)
Square Kilometre Array Science Data Challenge 1: analysis and results
Anna Bonaldi,Tao An,Marcus Brüggen,S. Burkutean,B. Coelho,H. Goodarzi,P. Hartley,P. K. Sandhu,C. Wu,Liangliang Yu,M. H. Zhoolideh Haghighi,Sonia Antón,Z. Bagheri,Domingos Barbosa,João Paulo Barraca,D. Bartashevich,Miguel Bergano,Matteo Bonato,Jan Brand,F. de Gasperin,A. Giannetti,Richard Dodson,Pankaj Jain,Sumit Jaiswal,Baoqiang Lao,B. S. Liu,Elisabetta Liuzzo,Yang Lu,V. Lukic,Dalmiro Maia,N. Marchili,Marcella Massardi,Prashanth Mohan,J. B. Morgado,M. Panwar,P. Prabhakar,V. A. R. M. Ribeiro,Kazi L.J. Rygl,V. Sabz Ali,Elham Saremi,Eugenio Schisano,Somayeh Sheikhnezami,A. Vafaei Sadr,A. Wong,O. I. Wong,O. I. Wong +45 more