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This is the second paper in a series whose aim is to predict the power spectrum of intensity and polarized intensity from cosmic reionization fronts. After building the analytic models for intensity and polarized intensity calculations in…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Emily Koivu , Heyang Long , Yuanyuan Yang , Christopher M. Hirata

During reionization, intergalactic ionization fronts (I-fronts) are sources of Ly$\alpha$ line radiation produced by collisional excitation of hydrogen atoms within the fronts. In principle, detecting this emission could provide direct…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-24 Bayu Wilson , Anson D'Aloisio , Christopher Cain , Eli Visbal , George D. Becker

The conditions within the ionization front of a quasar during reionization (T ~ 30,000 K, neutral hydrogen fraction ~ 0.5) are ideal for producing Lyman-alpha emission via collisional excitation of hydrogen atoms. Observations of this…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Frederick B. Davies , Steven R. Furlanetto , Matthew McQuinn

We present a formalism that incorporates hydrogen Lyman-alpha (Ly$\alpha$) polarization arising from the scattering of radiation in galaxy halos into the intensity mapping approach. Using the halo model, and emission profiles based on…

Astrophysics of Galaxies · Physics 2020-05-06 Lluís Mas-Ribas , Tzu-Ching Chang

We present new simulations of Lyman-$\alpha$ (Ly$\alpha$) intensity maps that include Ly$\alpha$ radiative transfer in the intergalactic medium (IGM) and all significant sources of Ly$\alpha$ photons. The sources considered include…

Astrophysics of Galaxies · Physics 2025-08-29 Abigail E. Ambrose , Eli Visbal , Mihir Kulkarni , Matthew McQuinn

We calculate the absolute intensity and anisotropies of the Lyman-alpha radiation field present during the epoch of reionization. We consider emission from both galaxies and the intergalactic medium (IGM) and take into account the main…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Marta B. Silva , Mario G. Santos , Yan Gong , Asantha Cooray , James Bock

Long troughs observed in the $z > 5.5$ Ly$\alpha$ and Ly$\beta$ forests are thought to be caused by the last remaining neutral patches during the end phases of reionization -- termed neutral islands. If this is true, then the longest…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-24 Bayu Wilson , Anson D'Aloisio , George D. Becker , Christopher Cain , Eli Visbal

We combine high resolution hydrodynamical simulations with an intermediate resolution, dark matter only simulation and an analytical model for the growth of ionized regions to estimate the large scale distribution and redshift evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Tirthankar Roy Choudhury , Ewald Puchwein , Martin G. Haehnelt , James S. Bolton

We use a large set of hydrodynamical simulations, combined with measurements of the Lyman alpha opacity of the IGM taken from the literature, to obtain robust estimates for the photoionization rate per hydrogen atom at z=5 and 6. We find…

Astrophysics · Physics 2009-11-13 James S. Bolton , Martin G. Haehnelt

The dynamical impact of Lyman-alpha (Ly{\alpha}) radiation pressure on galaxy formation depends on the rate and duration of momentum transfer between Ly{\alpha} photons and neutral hydrogen gas. Although photon trapping has the potential to…

Astrophysics of Galaxies · Physics 2016-12-07 Aaron Smith , Volker Bromm , Abraham Loeb

The density and temperature properties of the intergalactic medium (IGM) reflect the heating and ionization history during cosmological structure formation, and are primarily probed by the Lyman-alpha forest of neutral hydrogen absorption…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Bruno Villasenor , Brant Robertson , Piero Madau , Evan Schneider

With JWST, it is now possible to use Lyman-Alpha (Ly$\alpha$) emission from galaxies beyond z>8 to trace neutral hydrogen in the intergalactic medium (IGM) as the Universe became reionized. However, observed Ly$\alpha$ emission is scattered…

Estimates of the metagalactic hydrogen ionization rate from the Lyman-alpha forest opacity in QSO absorption spectra depend on the complex density distribution of neutral hydrogen along the line-of-sight. We use a large suite of high…

Astrophysics · Physics 2009-11-10 James S. Bolton , Martin G. Haehnelt , Matteo Viel , Volker Springel

We use cosmological hydrodynamical simulations to assess the feasibility of constraining the thermal history of the intergalactic medium during reionisation with the Ly$\alpha$ forest at $z\simeq5$. The integrated thermal history has a…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Fahad Nasir , James S. Bolton , George D. Becker

The Very Local Interstellar Medium (VLISM) neutral hydrogen and proton densities are still not precisely known even after three decades of deep space research and the existence of the EUV and other diagnostic data obtained by Pioneer 10/11,…

Astrophysics · Physics 2015-06-24 Pradip Gangopadhyay , Vlad Izmodenov , Mike Gruntman , Darrell Judge

We present a quantitative model of Lyman-alpha (Ly-alpha) emission throughout cosmic history and determine the prospects for intensity mapping of spatial fluctuations in the Ly-alpha signal. Since i) our model assumes at z>6 the minimum…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Anthony Pullen , Olivier Dore , Jamie Bock

We present the Technicolor Dawn simulations, a suite of cosmological radiation-hydrodynamic simulations of the first 1.2 billion years. By modeling a spatially-inhomogeneous UVB on-the-fly with 24 frequencies and resolving dark matter halos…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Kristian Finlator , Laura Keating , Benjamin D. Oppenheimer , Romeel Davé , Erik Zackrisson

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density…

Astrophysics · Physics 2009-10-31 Nickolay Y. Gnedin

The amplitude of the ionizing background that pervades the intergalactic medium (IGM) at the end of the epoch of reionization provides a valuable constraint on the emissivity of the sources which reionized the Universe. While measurements…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-28 Frederick B. Davies , Joseph F. Hennawi , Anna-Christina Eilers , Zarija Lukić

An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations. We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-12 Tsang Keung Chan , Alejandro Benitez-Llambay , Tom Theuns , Carlos Frenk , Richard Bower
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