Host group degeneracy in gravitational lensing time delay determination of
arXiv:2305.19151 · doi:10.1088/1475-7516/2023/08/065
Abstract
Massive elliptical galaxies, that serve as lenses in gravitational lensing time delay measurements of the Hubble parameter , often reside in a host group. We consider degeneracies in the modeling of the group halo. When the group effect on imaging can be summarized by its flexion (the next order term beyond shear in the tidal expansion), the posterior likelihood map can develop disjoint local minima, associated with an approximate discrete symmetry of a dominant flexion term. Monte-Carlo Markov Chain (MCMC) algorithms that are not designed to explore a rich posterior landscape can miss some of the minima, introducing systematic bias. We study mock data and demonstrate that the bias in can exceed , and pulls the inference value of above its truth value, for a reason that can be traced to the structure of a mismodeled flexion term. MCMC algorithms that are designed to cope with a rich posterior landscape can uncover the structure. If the group is X-ray bright enough, X-ray data may also help to resolve the degeneracy, by pinpointing the group's center of mass. Finally, we show that some implementations in the literature used an inaccurate kinematical prior, mis-modeling the group velocity dispersion by as much as
arXiv comment19 pages, matches JCAP version. Comments welcome!
References in corpus (63)
- Astropy: A Community Python Package for Astronomy
- emcee: The MCMC Hammer
- A Universal Density Profile from Hierarchical Clustering
- The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
- Weak Gravitational Lensing
- The SIMBAD astronomical database
- In the Realm of the Hubble tension a Review of Solutions
- The James Webb Space Telescope
- Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
- Planck 2018 results. I. Overview and the cosmological legacy of Planck
- Tensions between the Early and the Late Universe
- H0LiCOW XIII. A 2.4% measurement of from lensed quasars: tension between early and late-Universe probes
- Triaxial Modeling of Halo Density Profiles with High-resolution N-body Simulations
- Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
- The Power Spectrum Dependence of Dark Matter Halo Concentrations
- The Cosmological Analysis of the SDSS/BOSS data from the Effective Field Theory of Large-Scale Structure
- Cosmological Parameters from the BOSS Galaxy Power Spectrum
- Gravitationally lensed quasars and supernovae in future wide-field optical imaging surveys
- TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
- H0LiCOW - IX. Cosmographic analysis of the doubly imaged quasar SDSS 1206+4332 and a new measurement of the Hubble constant
- Two accurate time-delay distances from strong lensing: Implications for cosmology
- H0LiCOW I. Lenses in COSMOGRAIL's Wellspring: Program Overview
- Lenstronomy: multi-purpose gravitational lens modelling software package
- Cosmology with Phase 1 of the Square Kilometre Array; Red Book 2018: Technical specifications and performance forecasts
- A SHARP view of H0LiCOW: from three time-delay gravitational lens systems with adaptive optics imaging
- STRIDES: a 3.9 per cent measurement of the Hubble constant from the strong lens system DES J0408-5354
- Mass-sheet degeneracy, power-law models and external convergence: Impact on the determination of the Hubble constant from gravitational lensing
- Time Delay Cosmography
- TDCOSMO. I. An exploration of systematic uncertainties in the inference of from time-delay cosmography
- lenstronomy II: A gravitational lensing software ecosystem
- What Do Gravitational Lens Time Delays Measure?
- Gravitational lens modeling with basis sets
- Strong Lens Time Delay Challenge: II. Results of TDC1
- Pseudo Elliptical Lensing Mass Model: Application to the NFW Mass Distribution
- Weak Gravitational Flexion
- Galaxy-Galaxy Flexion: Weak Lensing to Second Order
- H0LiCOW XII. Lens mass model of WFI2033-4723 and blind measurement of its time-delay distance and
- A Spectroscopic Study of the Environments of Gravitational Lens Galaxies
- TDCOSMO. XII. Improved Hubble constant measurement from lensing time delays using spatially resolved stellar kinematics of the lens galaxy
- Scaling Properties of Galaxy Groups
- TDCOSMO V: strategies for precise and accurate measurements of the Hubble constant with strong lensing
- The Effect of Environment on Shear in Strong Gravitational Lenses
- zeus: A Python implementation of Ensemble Slice Sampling for efficient Bayesian parameter inference
- Weak lensing goes bananas: What flexion really measures
- On the accuracy of time-delay cosmography in the Frontier Fields Cluster MACS J1149.5+2223 with supernova Refsdal
- The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2016 follow-up campaign. I. Overview and classification of candidates selected by two techniques
- Could quasar lensing time delays hint to a core component in halos, instead of H0 tension?
- On the shape of dark matter halos from MultiDark Planck simulations
- Lensing degeneracies and mass substructure
- Line-of-sight effects in strong gravitational lensing
- Over-constrained Models of Time Delay Lenses Redux: How the Angular Tail Wags the Radial Dog
- Kinematics and Mass Profile of AWM 7
- A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: The Group Catalog
- Gravitational lensing tension from ultralight axion galactic cores
- The X-ray Properties of Moderate-redshift Galaxy Groups Selected by Association with Gravitational Lenses
- Detection of x-rays from galaxy groups associated with the gravitationally lensed systems PG 1115+080 and B1422+231
- Estimating cosmological parameters from future gravitational lens surveys
- STRIDES: Spectroscopic and photometric characterization of the environment and effects of mass along the line of sight to the gravitational lenses DES J0408-5354 and WGD 2038-4008
- TDCOSMO VIII: Cosmological distance measurements in light of the mass-sheet degeneracy -- forecasts from strong lensing and IFU stellar kinematics
- Domain of validity for pseudo-elliptical NFW lens models
- A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: Implications for
- Tightening weak lensing constraints on the ellipticity of galaxy-scale dark matter haloes
- The complex theory of gravitational lensing: Beltrami equation and cluster lensing