Results 21 to 30 of about 727 (169)
Annalen der Physik, Volume 535, Issue 7, July 2023., 2023 Implications for the cosmological model are explored of the assumption that the cosmic microwave background is subject to an SU(2) Yang– Mills theory of scale 10−4 eV rather than U(1) quantum thermodynamics. This concerns zeroth‐order (changes at high redshifts) and first‐order cosmological perturbations (changes at high and low redshifts).
Ralf Hofmann +2 more
wiley +1 more source
A very extended reionization epoch? [PDF]
Monthly Notices of the Royal Astronomical Society, 2005 The recent observations of cross temperature-polarization power spectra of the Cosmic Microwave Background (CMB) made by the WMAP satellite are in better agreement with a high value of the Thomson scattering optical depth \approx 0.17. This value is close to = 0.3, which is taken as the upper limit in the parameter extraction analysis made by the ...
Melchiorri, A. +3 more
openaire +2 more sources
The Astrophysical Journal, 2023 Baryons both increase halo concentration through adiabatic contraction and expel mass through feedback processes. However, it is not well understood how the radiation fields prevalent during the epoch of reionization affect the evolution of concentration
Hanjue Zhu, Nickolay Y. Gnedin
doaj +1 more source
Frontiers in Astronomy and Space Sciences, 2017 The reionization of helium at z ~ 3 is the final phase transition of the intergalactic medium and supposed to be driven purely by quasars. The He ii transverse proximity effect—enhanced He ii transmission in a background sightline caused by the ionizing ...
Tobias M. Schmidt +8 more
doaj +1 more source
Crossing the Rubicon of Reionization with z ∼ 5 QSOs
The Astrophysical Journal, 2023 One of the key open questions in cosmology is the nature of sources that completed cosmological hydrogen reionization at z ∼ 5.2. High- z primeval galaxies have been long considered the main drivers of reionization, with a minor role played by high- z ...
Andrea Grazian +14 more
doaj +1 more source
Self-regulated reionization [PDF]
Monthly Notices of the Royal Astronomical Society, 2007 Recently, we have presented the first large-scale radiative transfer simulations of reionization. Here we present new simulations which extend the source halo mass range downward to 10^8M_solar, to capture the full range of halo masses thought to be primarily responsible for reionization by their star formation following atomic hydrogen radiative ...
Iliev, Ilian T. +3 more
openaire +2 more sources
Reionization with Simba: How Much Does Astrophysics Matter in Modeling Cosmic Reionization?
The Astrophysical Journal, 2022 Abstract Traditional large-scale models of reionization usually employ simple deterministic relations between halo mass and luminosity to predict how reionization proceeds. We here examine the impact on modeling reionization of using more detailed models for the ionizing sources as identified within the 100 h −1 Mpc ...
Sultan Hassan +7 more
openaire +3 more sources
Patchy Kinetic Sunyaev–Zel’dovich Effect with Controlled Reionization History and Morphology
The Astrophysical Journal, 2023 Using the novel semi-numerical code for reionization AMBER, we model the patchy kinetic Sunyaev–Zel’dovich (kSZ) effect by directly specifying the reionization history with the redshift midpoint z _mid , duration Δ _z , and asymmetry A _z .
Nianyi Chen +3 more
doaj +1 more source
Cosmic Reionization Redux [PDF]
The Astrophysical Journal, 2006 Submitted to ApJ.
Gnedin, Nickolay Y., Fan, Xiaohui
openaire +2 more sources
Perspectives for Cosmological Reionization From Future CMB and Radio Projects
Frontiers in Astronomy and Space Sciences, 2018 In spite of the great recent results from the Planck satellite supporting cosmological reionization scenarios almost compatible with astrophysical models for the evolution of structure, galaxy and star formation, the full understanding of the ...
Tiziana Trombetti +4 more
doaj +1 more source