| 1. |
- Vrbanec, Dijana, et al.
(författare)
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Predictions for the 21 cm-galaxy cross-power spectrum observable with LOFAR and Subaru
- 2016
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 457:1, s. 666-675
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Tidskriftsartikel (refereegranskat)abstract
- The 21 cm-galaxy cross-power spectrum is expected to be one of the promising probes of the Epoch of Reionization (EoR), as it could offer information about the progress of reionization and the typical scale of ionized regions at different redshifts. With upcoming observations of 21 cm emission from the EoR with the Low Frequency Array (LOFAR), and of high-redshift Ly alpha emitters with Subaru's Hyper Suprime-Cam (HSC), we investigate the observability of such cross-power spectrum with these two instruments, which are both planning to observe the ELAIS-N1 field at z = 6.6. In this paper, we use N-body + radiative transfer (both for continuum and Ly alpha photons) simulations at redshift 6.68, 7.06 and 7.3 to compute the 3D theoretical 21 cm-galaxy cross-power spectrum and cross-correlation function, as well as to predict the 2D 21 cm-galaxy cross-power spectrum and cross-correlation function expected to be observed by LOFAR and HSC. Once noise and projection effects are accounted for, our predictions of the 21 cm-galaxy cross-power spectrum show clear anti-correlation on scales larger than similar to 60 h(-1) Mpc (corresponding to k similar to 0.1 h Mpc(-1)), with levels of significance p = 0.003 at z = 6.6 and p = 0.08 at z = 7.3. On smaller scales, instead, the signal is completely contaminated. On the other hand, our 21 cm-galaxy cross-correlation function is strongly contaminated by noise on all scales, since the noise is no longer being separated by its k modes.
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| 2. |
- Vrbanec, Dijana, et al.
(författare)
-
Predictions for the 21cm-galaxy cross-power spectrum observable with SKA and future galaxy surveys
- 2020
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 492:4, s. 4952-4958
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we use radiative transfer+N-body simulations to explore the feasibility of measurements of cross-correlations between the 21-cm field observed by the Square Kilometre Array (SKA) and high-z Lyman alpha emitters (LAEs) detected in galaxy surveys with the Subaru Hyper Suprime-Cam (HSC), Subaru Prime Focus Spectrograph (PFS), and Wide Field Infrared Survey Telescope (WFIRST). 2 lcm-LAE cross-correlations are in fact a powerful probe of the epoch of reionization as they are expected to provide precious information on the progress of reionization and the typical scale of ionized regions at different redshifts. The next generation observations with SKA will have a noise level much lower than those with its precursor radio facilities, introducing a significant improvement in the measurement of the cross-correlations. We find that an SKA-HSC/PFS observation will allow to investigate scales below 10 and similar to 60 h(-1) Mpc at z = 7.3 and 6.6, respectively. WHR,ST will allow to access also higher redshifts, as it is expected to observe spectroscopically similar to 900 LAEs per deg(2) and unit redshi in the range 7.5 <= z <= 8.5. Because of the reduction of the shot noise compared to HSC and PFS, observations with WFIRST will result in more precise cross-correlations and increased observable scales.
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