Efficient photoheating algorithms in time-dependent photoionization simulations
Number of Authors: 3
2016 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 455, no 4, 4406-4425 p.Article in journal (Refereed) Published
We present an extension to the time-dependent photoionization code C-2-RAY to calculate photoheating in an efficient and accurate way. In C-2-RAY, the thermal calculation demands relatively small time-steps for accurate results. We describe two novel methods to reduce the computational cost associated with small time-steps, namely, an adaptive time-step algorithm and an asynchronous evolution approach. The adaptive time-step algorithm determines an optimal time-step for the next computational step. It uses a fast ray-tracing scheme to quickly locate the relevant cells for this determination and only use these cells for the calculation of the time-step. Asynchronous evolution allows different cells to evolve with different time-steps. The asynchronized clocks of the cells are synchronized at the times where outputs are produced. By only evolving cells which may require short time-steps with these short time-steps instead of imposing them to the whole grid, the computational cost of the calculation can be substantially reduced. We show that our methods work well for several cosmologically relevant test problems and validate our results by comparing to the results of another time-dependent photoionization code.
Place, publisher, year, edition, pages
2016. Vol. 455, no 4, 4406-4425 p.
radiative transfer, methods: numerical, H II regions, intergalactic medium, dark ages reionization first stars
Astronomy, Astrophysics and Cosmology
Research subject Astronomy
IdentifiersURN: urn:nbn:se:su:diva-126887DOI: 10.1093/mnras/stv2556ISI: 000368009300077OAI: oai:DiVA.org:su-126887DiVA: diva2:905232