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Related papers: Spatial fluctuations of the intergalactic temperat…

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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

Using high redshift radio sources as background, the 21cm forest observations probe the neutral hydrogen absorption signatures of early structures along the lines of sight. Directly sensitive to the spin temperature, it complements the 21cm…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-18 Yidong Xu , Xuelei Chen , Zuhui Fan , Hy Trac , Renyue Cen

Recent He II Lyman-alpha forest observations from 2.0 < z < 3.2 show large fluctuations in the optical depth at z > 2.7. These results point to a fluctuating He-ionizing background, which may be due to the end of helium reionization of this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Keri L. Dixon , Steven R. Furlanetto , Andrei Mesinger

We investigate self-shielding of intergalactic hydrogen against ionizing radiation in radiative transfer simulations of cosmic reionization carefully calibrated with Lyman alpha forest data. While self-shielded regions manifest as…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Jonathan Chardin , Girish Kulkarni , Martin G. Haehnelt

We use a probabilistic method to compute the propagation of an ionization front corresponding to the re-ionization of the intergalactic medium in a LCDM cosmology, including both hydrogen and helium. The effects of radiative transfer…

Astrophysics · Physics 2009-11-10 James Bolton , Avery Meiksin , Martin White

The time frame in which hydrogen reionization occurred is highly uncertain, but can be constrained by observations of Lyman-alpha (Ly$\alpha$) emission from distant sources. Neutral hydrogen in the intergalactic medium (IGM) attenuates…

Astrophysics of Galaxies · Physics 2021-10-05 Alexa Morales , Charlotte Mason , Sean Bruton , Max Gronke , Francesco Haardt , Claudia Scarlata

The thermal evolution of the intergalactic medium (IGM) can serve as a sensitive probe of cosmological heat sources and sinks. We employ it to limit interactions between dark matter and baryons. After reionization the IGM temperature is set…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-13 Julian B. Muñoz , Abraham Loeb

The intergalactic medium (IGM) underwent intense heating that resulted in pressure disequilibrium in the wake of ionization fronts during cosmic reionization. The dynamical relaxation to restore pressure balance may have driven small-scale…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Christopher Cain , Matthew McQuinn , Evan Scannapieco , Anson D'Aloisio , Hy Trac

We develop a method to extract the "effective equation of state" of the intergalactic medium from the doppler b parameter distribution of the low-density Lyman-alpha forest. We test the method on numerical simulations and then apply it to…

Astrophysics · Physics 2009-10-26 Massimo Ricotti , Nickolay Y. Gnedin , J. Michael Shull

The post-reionization thermal state of the intergalactic medium is characterized by a power-law relationship between temperature and density, with a slope determined by the parameter $\gamma$. We describe a new method to measure $\gamma$…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-16 Elisa Boera , Michael T. Murphy , George D. Becker , James S. Bolton

The thermal state of the intergalactic medium (IGM) provides an indirect probe of both the HI and HeII reionisation epochs. Current constraints on the IGM temperature from the Lya forest are restricted to the redshift range 2<z<4.5,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 James S. Bolton , George D. Becker , J. Stuart B. Wyithe , Martin G. Haehnelt , Wallace L. W. Sargent

We develop a semi-analytic method for assessing the impact of the large-scale IGM temperature fluctuations expected following He${\rm\,{\scriptstyle II}}$ reionization on three-dimensional clustering measurements of the Ly$\alpha$ forest.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Bradley Greig , James S. Bolton , J. Stuart B. Wyithe

We present measurements of the intergalactic medium (IGM) temperature within ~5 proper Mpc of seven luminous quasars at z~6. The constraints are obtained from the Doppler widths of Lyman-alpha absorption lines in the quasar near-zones and…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 James S. Bolton , George D. Becker , Sudhir Raskutti , J. Stuart B. Wyithe , Martin G. Haehnelt , Wallace L. W. Sargent

We present cosmological, radiation-hydrodynamics simulations of galaxy formation during the epoch of reionization in an effort towards modelling the interstellar medium (ISM) and interpreting ALMA observations. Simulations with and without…

Astrophysics of Galaxies · Physics 2018-05-02 Harley Katz , Taysun Kimm , Debora Sijacki , Martin Haehnelt

Recent observations suggest that hydrogen reionization ends late ($z \simeq 6$) and proceeds quickly. We present here a new model of the meta-galactic UV/X-ray background (UVB) that is consistent with this. It adopts the most recent…

Astrophysics of Galaxies · Physics 2019-01-30 Ewald Puchwein , Francesco Haardt , Martin G. Haehnelt , Piero Madau

Recent work has suggested that, during reionisation, spatial variations in the ionising radiation field should produce enhanced Ly ${\alpha}$ forest transmission at distances of tens of comoving Mpc from high-redshift galaxies. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-18 Luke Conaboy , James S. Bolton , Laura C. Keating , Martin G. Haehnelt , Girish Kulkarni , Ewald Puchwein

The high-redshift intergalactic medium (IGM) and the primeval galaxy population are rapidly becoming the new frontier of extra-galactic astronomy. We investigate the IGM properties and their connection to galaxies at $z\geq5.5$ under…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-23 Enrico Garaldi , Rahul Kannan , Aaron Smith , Volker Springel , Rüdiger Pakmor , Mark Vogelsberger , Lars Hernquist

The latest measurements of CMB electron scattering optical depth reported by Planck significantly reduces the allowed space of HI reionization models, pointing toward a later ending and/or less extended phase transition than previously…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-30 J. Oñorbe , J. F. Hennawi , Z. Lukić , M. Walther

The recent EDGES measurements of the global 21-cm signal from the cosmic dawn suggest that the kinetic temperature of the inter-galactic medium (IGM) might be significantly lower compared to its expected value. The colder IGM directly…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-02 Kanan K. Datta , Aritra Kundu , Ankit Paul , Ankita Bera

Using the CoDa II simulation, we study the Ly$\alpha$ transmissivity of the intergalactic medium (IGM) during reionization. At $z>6$, a typical galaxy without an active galactic nucleus fails to form a proximity zone around itself due to…

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