%0 Generic %1 Puchwein2011 %A Puchwein, Ewald %A Pfrommer, Christoph %A Springel, Volker %A Broderick, Avery E. %A Chang, Philip %D 2011 %K forest lya simulation %T The Lyman-alpha forest in a blazar-heated Universe %U http://arxiv.org/abs/1107.3837 %X It has been realised only recently that TeV emission from blazars can significantly heat the intergalactic medium (IGM) by pair-producing high-energy electrons and positrons, which in turn excite vigorous plasma instabilities, leading to a local dissipation of the pairs' kinetic energy. In this work, we use cosmological hydrodynamical simulations to model the impact of this induced blazar heating on the Lyman-alpha forest at intermediate redshifts (z~2-3). We find that blazar heating produces an inverted equation-of-state in the IGM and naturally resolves many of the problems present in previous simulations of the forest that included photoionisation heating alone. In particular, our simulation results simultaneously reproduce the observed effective optical depth and temperature as a function of redshift, the observed probability distribution functions (PDFs) of the transmitted flux, and the observed flux power spectra, over the full redshift range 2<z<3 analysed here. Additionally, by deblending the absorption features of Lyman-alpha spectra into a sum of thermally broadened individual lines, we find superb agreement with the observed lower cutoff of the line-width distribution and abundances of neutral hydrogen column densities per unit redshift. Using the most recent constraints on the cosmic ultraviolet (UV) background, this excellent agreement with observations is obtained without re-scaling the amplitude of the UV background; a procedure that was routinely used in the past to match the observed level of transmitted flux. This concordance between Lyman-alpha data and simulation results, which are based on the most recent cosmological parameters, also suggests that the inclusion of blazar heating alleviates previous tensions on constraints for sigma_8 derived from Lyman-alpha measurements and other cosmological data. abridged

@misc{Puchwein2011, abstract = { It has been realised only recently that TeV emission from blazars can significantly heat the intergalactic medium (IGM) by pair-producing high-energy electrons and positrons, which in turn excite vigorous plasma instabilities, leading to a local dissipation of the pairs' kinetic energy. In this work, we use cosmological hydrodynamical simulations to model the impact of this induced blazar heating on the Lyman-alpha forest at intermediate redshifts (z~2-3). We find that blazar heating produces an inverted equation-of-state in the IGM and naturally resolves many of the problems present in previous simulations of the forest that included photoionisation heating alone. In particular, our simulation results simultaneously reproduce the observed effective optical depth and temperature as a function of redshift, the observed probability distribution functions (PDFs) of the transmitted flux, and the observed flux power spectra, over the full redshift range 2<z<3 analysed here. Additionally, by deblending the absorption features of Lyman-alpha spectra into a sum of thermally broadened individual lines, we find superb agreement with the observed lower cutoff of the line-width distribution and abundances of neutral hydrogen column densities per unit redshift. Using the most recent constraints on the cosmic ultraviolet (UV) background, this excellent agreement with observations is obtained without re-scaling the amplitude of the UV background; a procedure that was routinely used in the past to match the observed level of transmitted flux. This concordance between Lyman-alpha data and simulation results, which are based on the most recent cosmological parameters, also suggests that the inclusion of blazar heating alleviates previous tensions on constraints for sigma_8 derived from Lyman-alpha measurements and other cosmological data. [abridged] }, added-at = {2011-07-22T23:42:43.000+0200}, author = {Puchwein, Ewald and Pfrommer, Christoph and Springel, Volker and Broderick, Avery E. and Chang, Philip}, biburl = {https://www.bibsonomy.org/bibtex/2fa7fbcc13129a3427c5a294217e12f14/miki}, description = {[1107.3837] The Lyman-alpha forest in a blazar-heated Universe}, interhash = {c4332bf64dc04fa138192a5d980ec7b6}, intrahash = {fa7fbcc13129a3427c5a294217e12f14}, keywords = {forest lya simulation}, note = {cite arxiv:1107.3837Comment: 15 pages, 13 figures, submitted to MNRAS}, timestamp = {2011-07-22T23:42:43.000+0200}, title = {The Lyman-alpha forest in a blazar-heated Universe}, url = {http://arxiv.org/abs/1107.3837}, year = 2011 }