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تسجيل مستخدم جديدPrimordial magnetic fields and the HI signal from the epoch of reionization
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The implication of primordial magnetic-field-induced structure formation for the HI signal from the epoch of reionization is studied. Using semi-analytic models, we compute both the density and ionization inhomogeneities in this scenario. We show that: (a) The global HI signal can only be seen in emission, unlike in the standard $Lambda$CDM models, (b) the density perturbations induced by primordial fields, leave distinctive signatures of the magnetic field Jeans length on the HI two-point correlation function, (c) the length scale of ionization inhomogeneities is $la 1 rm Mpc$. We find that the peak expected signal (two-point correlation function) is $simeq 10^{-4} rm K^2$ in the range of scales $0.5hbox{-}3 rm Mpc$ for magnetic field strength in the range $5 times 10^{-10} hbox{-}3 times 10^{-9} rm G$. We also discuss the detectability of the HI signal. The angular resolution of the on-going and planned radio interferometers allows one to probe only the largest magnetic field strengths that we consider. They have the sensitivity to detect the magnetic field-induced features. We show that thefuture SKA has both the angular resolution and the sensitivity to detect the magnetic field-induced signal in the entire range of magnetic field values we consider, in an integration time of one week.
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