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arXiv · 1801.06527

New simulation of QSO X-ray heating during the Cosmic Dawn

Hannah Ross·Keri Dixon·Garrelt Mellema·Ilian Iliev
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Abstract

The upcoming radio interferometer Square Kilometre Array is expected to directly detect the redshifted 21-cm signal from the Cosmic Dawn for the first time. In this era temperature fluctuations from X-ray heating of the neutral intergalactic medium can impact this signal dramatically. Previously, in (Ross et al, 2017), we presented the first large-volume, 244 $h^{-1}$Mpc = 349 Mpc a side, fully numerical radiative transfer simulations of X-ray heating. This work is a follow-up where we now also consider QSO-like sources in addition to high mass X-ray binaries. Images of the two cases are clearly distinguishable at SKA1-LOW resolution and have RMS fluctuations above the expected noise. The inclusion of QSOs leads to a dramatic increase in non-Gaussianity of the signal, as measured by the skewness and kurtosis of the 21-cm signal. We conclude that this increased non-Gaussianity is a promising signature of early QSOs.

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Hannah Ross, Keri Dixon, Garrelt Mellema, Ilian Iliev. 2018-01-19. New simulation of QSO X-ray heating during the Cosmic Dawn. https://doi.org/10.1017/s1743921317011115

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