Cosmology from clustering, cosmic shear, CMB lensing, and cross correlations: combining Rubin observatory and Simons Observatory

Xiao Fang, Tim Eifler, Emmanuel Schaan, Hung Jin Huang, Elisabeth Krause, Simone Ferraro

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

In the near future, the overlap of the Rubin Observatory Legacy Survey of Space and Time (LSST) and the Simons Observatory (SO) will present an ideal opportunity for joint cosmological data set analyses. In this paper, we simulate the joint likelihood analysis of these two experiments using six two-point functions derived from galaxy position, galaxy shear, and CMB lensing convergence fields. Our analysis focuses on realistic noise and systematics models and we find that the dark energy Figure of merit (FoM) increases by 53 per cent (92 per cent) from LSST-only to LSST+SO in Year 1 (Year 6). We also investigate the benefits of using the same galaxy sample for both clustering and lensing analyses, and find the choice improves the overall signal to noise by ∼30−40 per cent, which significantly improves the photo-z calibration and mildly improves the cosmological constraints. Finally, we explore the effects of catastrophic photo-z outliers finding that they cause significant parameter biases when ignored. We develop a new mitigation approach termed ‘island model’, which corrects a large fraction of the biases with only a few parameters while preserving the constraining power.

Original languageEnglish (US)
Pages (from-to)5721-5736
Number of pages16
JournalMonthly Notices of the Royal Astronomical Society
Volume509
Issue number4
DOIs
StatePublished - Feb 1 2022

Keywords

  • cosmological parameters
  • cosmology: theory
  • large-scale structure of Universe

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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