TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
By Simon Birrer, Anowar J. Shajib, A. Galan, M. Millon, T. Treu, A. Agnello, M. Auger, G. C. Chen, L. Christensen, T. Collett and 17 more. 2020
260 citations recorded by the source corpus.
The H0LiCOW collaboration inferred via gravitational lensing time delays a Hubble constant $H_0=73.3^{+1.7}_{-1.8}$ km s$^{-1}{\rm Mpc}^{-1}$, describing deflector mass density profiles by either a power-law or stars plus standard dark matter halos. The mass-sheet transform (MST) that leaves the lensing observables unchanged is considered the dominant source of residual uncertainty in $H_0$. We quantify any potential effect of the MST with flexible mass models that are maximally degenerate with H0. Our calculation is based on a new hierarchical approach in which the MST is only constrained by stellar kinematics. The approach is validated on hydrodynamically simulated lenses. We apply the method to the TDCOSMO sample of 7 lenses (6 from H0LiCOW) and measure $H_0=74.5^{+5.6}_{-6.1}$ km s$^{-1}{\rm Mpc}^{-1}$. In order to further constrain the deflector mass profiles, we then add imaging and spectroscopy for 33 strong gravitational lenses from the SLACS sample. For 9 of the SLAC lenses we use resolved kinematics to constrain the stellar anisotropy. From the joint analysis of the TDCOSMO+SLACS sample, we measure $H_0=67.4^{+4.1}_{-3.2}$ km s$^{-1}{\rm Mpc}^{-1}$, assuming that the TDCOSMO and SLACS galaxies are drawn from the same parent population. The blind H0LiCOW, TDCOSMO-only and TDCOSMO+SLACS analyses are in mutual statistical agreement. The TDCOSMO+SLACS analysis prefers marginally shallower mass profiles than H0LiCOW or TDCOSMO-only. While our new analysis does not statistically invalidate the mass profile assumptions by H0LiCOW, and thus their $H_0$ measurement relying on those, it demonstrates the importance of understanding the mass density profile of elliptical galaxies. The uncertainties on $H_0$ derived in this paper can be reduced by physical or observational priors on the form of the mass profile, or by additional data, chiefly spatially resolved kinematics of lens galaxies.
Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics
View Paper: https://www.semanticscholar.org/paper/951a5adfed833ac759fddfc6afad7b4661e596ab
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Citations in the corpus
- The Atacama Cosmology Telescope: DR4 maps and cosmological parameters (2020, unknown): “It also disagrees at 3σ with the H0liCOW estimate from strong lenses [13] but agrees with the more recent TDCOSMO/H0LiCOW revised estimate including more flexible lens mass profile modeling and use of stellar kinematics data [14].”
- The Ups and Downs of Early Dark Energy solutions to the Hubble tension: A review of models, hints and constraints circa 2023 (2023, background): “time-delay of strongly-lensed quasars [3, 33, 34], maser distances [35], cosmic chronometers [36], the age of old stars [36–38] or gravitational waves as “standard sirens” [39].”
- Hubble Tension: The Evidence of New Physics (2023, methodology): “After that, the TDCOSMO IV re-analysis lowers the H0 estimates and increases the error bar [486].”
- A buyer’s guide to the Hubble constant (2021, methodology): “A re-analysis has been undertaken by the TD Cosmo team (Birrer et al. 2020).”
- The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters (2023, methodology): “Among direct measurements, we show the TDCOSMO strong-lensing time-delay measurement with marginalization over lens profiles (Birrer et al. 2020), an alternative TDCOSMO measurement with different lensmass assumptions (Birrer et al. 2020), the tip-of-thered-giant-branch (TRGB) calibrated supernovae…”
- Cosmology Intertwined II: The Hubble Constant Tension (2020, unknown): “[20] S.”