http://arxiv.org/abs/1611.09682
We study 21 cm and Ly$\mathrm{\alpha}$ fluctuations, as well as H$\mathrm{\alpha}$, while distinguishing for Ly$\mathrm{\alpha}$ between emission of galactic, diffuse and scattered IGM origin. Cross-correlation information about the state of the IGM is worked out, testing neutral versus ionized medium with different tracers in a semi-numerical simulation setup. In order to path the way for constraints on reionization history and modelling beyond power spectrum information, we explore parameter dependencies of the cross-power signal between 21$\,$cm and Ly$\mathrm{\alpha}$, which displays characteristic morphology and a turn-over from negative to positive correlation at scales of a couple Mpc$^{-1}$. In a proof of concept for the extraction of further information on the state of the IGM using different tracers, we demonstrate the usage of the 21$\,$cm and H$\mathrm{\alpha}$ cross-correlation signal to determine the relative strength of galactic and IGM emission in Ly$\mathrm{\alpha}$. We conclude by showing the detectability of the 21$\,$cm and Ly$\mathrm{\alpha}$ cross-correlation signal over about one decade in scale at high S/N for upcoming probes like SKA and the proposed all-sky intensity mapping satellite SPHEREx, while also including the Ly$\mathrm{\alpha}$ damping tail as well as 21 cm foreground avoidance in the modelling.
C. Heneka, A. Cooray and C. Feng
Wed, 30 Nov 16
25/69
Comments: 26 pages, 17 figures, 3 tables
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