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Abstract: We present an efficient method to generate large simulations of the Epoch ofReionization EoR without the need for a full 3-dimensional radiative transfercode. Large dark-matter-only simulations are post-processed to produce maps ofthe redshifted 21cm emission from neutral hydrogen. Dark matter haloes areembedded with sources of radiation whose properties are either based onsemi-analytical prescriptions or derived from hydrodynamical simulations. Thesesources could either be stars or power-law sources with varying spectralindices. Assuming spherical symmetry, ionized bubbles are created around thesesources, whose radial ionized fraction and temperature profiles are derivedfrom a catalogue of 1-D radiative transfer experiments. In case of overlap ofthese spheres, photons are conserved by redistributing them around theconnected ionized regions corresponding to the spheres. The efficiency withwhich these maps are created allows us to span the large parameter spacetypically encountered in reionization simulations. We compare our results withother, more accurate, 3-D radiative transfer simulations and find excellentagreement for the redshifts and the spatial scales of interest to upcoming 21cmexperiments. We generate a contiguous observational cube spanning redshift 6 to12 and use these simulations to study the differences in the reionizationhistories between stars and quasars. Finally, the signal is convolved with theLOFAR beam response and its effects are analyzed and quantified. Statisticsperformed on this mock data set shed light on possible observational strategiesfor LOFAR.



Autor: Rajat M. Thomas, Saleem Zaroubi, Benedetta Ciardi, Andreas H. Pawlik, Panagiotis Labropoulos, Vibor Jelic, Gianni Bernardi, Michi

Fuente: https://arxiv.org/







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