Synergies between intensity maps of hydrogen lines. Issue 3 (28th June 2018)

• Record Type: Journal Article
• Authors: Fonseca, José; Maartens, Roy; Santos, Mário G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 479:Issue 3(2018)
• Page Start: 3490
• Page End: 3497
• Publication Date: 2018-06-28
• Subjects: cosmological parameters -- large-scale structure of Universe -- cosmology: miscellaneous; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty1702
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We study synergies between Hi 21 cm and H α intensity map observations, focusing on SKA1-like and SPHEREx-like surveys. We forecast how well such a combination can measure features in the angular power spectrum on the largest scales, that arise from primordial non-Gaussianity and from general relativistic effects. For the first time we consider Doppler, Sachs–Wolfe, and integrated SW effects separately. We confirm that the single-tracer surveys on their own cannot detect general relativistic effects and can constrain the non-Gaussianity parameter f NL only slightly better than Planck. Using the multitracer technique, constraints on f NL can be pushed down to ∼1. Amongst the general relativistic effects, the Doppler term is detectable with the multitracer. The Sachs–Wolfe terms and the integrated SW effect are still not detectable.