2019/04/23 by Shoichiro Tanaka, Shintaro Yoshiura, Tanaka, Shoichiro +9
Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology
paper · pdf · doi:10.48550/arxiv.1904.10363
openalex publication_date 2019/04/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Neutral hydrogen (H\rm I) intensity mapping is capable of measuring redshift evolution of H\rm I density parameter Ω_\rm H\rm I, which is an important parameter to understand structure formation in the post-reionization epoch. Future H\rm I observation with Square Kilometre Array (SKA) can significantly improve constraints on the parameter. However, the observation of H\rm I suffers from the contamination from extremely bright foreground emissions, and it is necessary to consider a signal validation method complementary to the measurement of H\rm I auto power spectrum. In this work, we propose to take a cross correlation between a 21cm-line intensity map and a convergence map reconstructed from observation of the cosmic microwave background by Planck and estimate expected ideal constraints on cosmological parametersby ignoring the foreground contamination. We find that the SKA1-mid operated in single-dish mode has a sufficient capability to detect the cross correlation on the large scales. Further, by Fisher analysis assuming a constant linear bias of H\rm I, b, and SKA1-mid observation of 1,000 hours for each of Band 1 and 2, we show that Ω_\rm H\rm I b can be constrained with a precision of 6-13% at a wide range of redshifts of 0.0