English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Large-scale simulations of H and He reionization and heating driven by stars and more energetic sources

MPS-Authors
/persons/resource/persons207385

Eide,  Marius B.
Computational Structure Formation, MPI for Astrophysics, Max Planck Society;

/persons/resource/persons18445

Ciardi,  Benedetta
Computational Structure Formation, MPI for Astrophysics, Max Planck Society;

/persons/resource/persons209317

Busch,  Philipp
Computational Structure Formation, MPI for Astrophysics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Eide, M. B., Ciardi, B., Graziani, L., Busch, P., Feng, Y., & Matteo, T. D. (2020). Large-scale simulations of H and He reionization and heating driven by stars and more energetic sources. Monthly Notices of the Royal Astronomical Society, 498(4), 6083-6099. doi:10.1093/mnras/staa2774.


Cite as: http://hdl.handle.net/21.11116/0000-0007-D6F4-4
Abstract
We present simulations of cosmic reionization and reheating from z = 18 to z = 5, investigating the role of stars (emitting soft UV-photons), nuclear black holes (BHs, with power-law spectra), X-ray binaries (XRBs, with hard X-ray dominated spectra), and the supernova-associated thermal bremsstrahlung of the diffuse interstellar medium (ISM, with soft X-ray spectra). We post-process the hydrodynamical simulation MassiveBlack-II (MBII) with multifrequency ionizing radiative transfer. The source properties are directly derived from the physical environment of MBII, and our only real free parameter is the ionizing escape fraction fesc. We find that, among the models explored here, the one with an escape fraction that decreases with decreasing redshift yields results most in line with observations, such as of the neutral hydrogen fraction and the Thomson scattering optical depth. Stars are the main driver of hydrogen reionization and consequently of the thermal history of the intergalactic medium (IGM). We obtain 〈xH ii〉 = 0.99998 at z = 6 for all source types, with volume-averaged temperatures ⟨T⟩∼20000 K. BHs are rare and negligible to hydrogen reionization, but conversely they are the only sources that can fully ionize helium, increasing local temperatures by ∼104 K. The thermal and ionization state of the neutral and lowly ionized hydrogen differs significantly with different source combinations, with ISM and (to a lesser extent) XRBs, playing a significant role and, as a consequence, determining the transition from absorption to emission of the 21-cm signal from neutral hydrogen.