Kinematic lensing with the Roman Space Telescope

Jiachuan Xu, Tim Eifler, Eric Huff, R. S. Pranjal, Hung Jin Huang, Spencer Everett, Elisabeth Krause

Research output: Contribution to journalArticlepeer-review


Kinematic lensing (KL) is a new cosmological measurement technique that combines traditional weak lensing (WL) shape measurements of disc galaxies with their kinematic information. Using the Tully–Fisher relation, KL breaks the degeneracy between intrinsic and observed ellipticity and significantly reduces the impact of multiple systematics that are present in traditional WL. We explore the performance of KL given the instrument capabilities of the Roman Space Telescope, assuming overlap of the High Latitude Imaging Survey (HLIS) and the High Latitude Spectroscopy Survey (HLSS) over 2000 deg2. Our KL suitable galaxy sample has a number density of ngal = 4 arcmin−1 with an estimated shape noise level of σ = 0.035. We quantify the cosmological constraining power on Ωm–S8 and wp–wa by running simulated likelihood analyses that account for redshift and shear calibration uncertainties, intrinsic alignment, and baryonic feedback. Compared to a traditional WL survey, we find that KL significantly improves the constraining power on Ωm–S8 (FoMKL = 1.70FoMWL) and wp–wa (FoMKL = 3.65FoMWL). We also explore a ‘narrow tomography KL survey’ using 30 instead of the default 10 tomographic bins; however, we find no meaningful enhancement to the figure of merit even when assuming a significant time dependence in our fiducial dark energy input scenarios.

Original languageEnglish (US)
Pages (from-to)2535-2551
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - Feb 1 2023


  • cosmological parameters
  • dark energy
  • gravitational lensing: weak
  • methods: numerical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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