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Related papers: Forecasting constraints on the high-z IGM thermal …

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We have run a new suite of simulations that solve hydrodynamics and radiative transfer simultaneously to study helium II reionization. Our suite of simulations employs various models for populating quasars inside of dark matter halos, which…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-11 Paul La Plante , Hy Trac , Rupert Croft , Renyue Cen

We present a new approach to measure the power-law temperature density relationship $T=T_0 (\rho / \bar{\rho})^{\gamma -1}$ and the UV background photoionization rate $\Gamma_{\rm HI}$ of the IGM based on the Voigt profile decomposition of…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-18 Teng Hu , Vikram Khaire , Joseph F. Hennawi , Michael Walther , Hector Hiss , Justin Alsing , Jose Oñorbe , Zarija Lukic , Frederick Davies

We explore how the assumption of ionization equilibrium modulates the modeled intergalactic medium (IGM) at the end of the hydrogen Epoch of Reionization using the cosmological radiation hydrodynamic \textsc{Technicolor Dawn} simulation. In…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Samir Kušmić , Kristian Finlator , Laura Keating , Ezra Huscher

The recent measurement by WMAP of a large electron scattering optical depth tau_e = 0.17 +- 0.04 is consistent with a simple model of reionization in which the intergalactic medium (IGM) is ionized at redshift z ~ 15, and remains highly…

Astrophysics · Physics 2009-11-07 Lam Hui , Zoltan Haiman

The physical conditions of the intergalactic medium (IGM) during the final stages of cosmic reionization ($z\sim5.0-6.0$) are not yet fully understood. Recent reports of unexpectedly large-scale ($\ge 150 h^{-1}\mathrm{cMpc}$) correlation…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-12 Barun Maity , Frederick B. Davies , Benedetta Spina , Sarah E. I. Bosman

The intergalactic neutral hydrogen which is responsible for the Lyman alpha forest of quasar absorption is a tracer of much larger amounts of ionised hydrogen. The ionised component has yet to be detected directly, but is expected to…

Astrophysics · Physics 2009-11-11 Rupert A. C. Croft , A. J. Banday , Lars Hernquist

According to the photo-heating model of the intergalactic medium (IGM), He II reionization is expected to affect its thermal evolution. Evidence for additional energy injection into the IGM has been found at $3\lesssim z\lesssim4$, though…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Elisa Boera , Michael T. Murphy , George D. Becker , James S. Bolton

The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of galaxy formation in gravitational models of…

In the process of producing the roughly three ionizing photons per atom required to reionize the IGM, the same massive stars explode and eject metals into their surroundings. While the overly sensitive Lya transition makes Gunn-Peterson…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-24 Suk Sien Tie , Joseph F. Hennawi , Feige Wang , Silvia Onorato , Jinyi Yang , Eduardo Bañados , Frederick B. Davies , Jose Oñorbe

In this article, the temperature-density relation of the intergalactic medium was studied in the region $1.6 \leq z < 2.0$ divided into two bins. For this purpose, the Ly-$\alpha$ forest decomposition into individual absorption profiles was…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Tomáš Ondro , Rudolf Gális

We use an analytic model to study how inhomogeneous hydrogen reionization affects the temperature distribution of the intergalactic medium (IGM). During this process, the residual energy of each ionizing photon is deposited in the IGM as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Steven Furlanetto , S. Peng Oh

At low densities the standard ionisation history of the intergalactic medium (IGM) predicts a decreasing temperature of the IGM with decreasing density once hydrogen (and helium) reionisation is complete. Heating the high-redshift,…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 A. Rorai , G. D. Becker , M. G. Haehnelt , R. F. Carswell , J. S. Bolton , S. Cristiani , V. D'Odorico , G. Cupani , P. Barai , F. Calura , T. -S. Kim , E. Pomante , E. Tescari , M. Viel

We characterise the thermal state of the intergalactic medium (IGM) in ten redshift bins in the redshift range $2 \leq z \leq 4$ with a sample of 103 high resolution, high S/N Ly$\alpha$ forest spectra using four different flux distribution…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-20 Prakash Gaikwad , Raghunathan Srianand , Martin G. Haehnelt , Tirthankar Roy Choudhury

The Lyman-$\alpha$ forest opacity fluctuations observed from high-redshift quasar spectra have been proven to be extremely successful in order to probe the late phase of the reionization epoch. For ideal modeling of these opacity…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-28 Barun Maity , Frederick Davies , Prakash Gaikwad

Understanding the sources responsible for reionizing the Universe is a key goal of observational cosmology. A discrepancy has existed between the metagalactic hydrogen ionization rate, Gamma_HI, predicted by early hydrodynamical simulations…

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

The Ly$\alpha$ forest transmission probability distribution function (PDF) is an established probe of the intergalactic medium (IGM) astrophysics, especially the temperature-density relationship of the IGM. We measure the transmission PDF…

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

Lyman-alpha forest absorption spectra towards quasars at z ~ 6 show regions of enhanced transmission close to their source. Several authors have argued that the apparently small sizes of these regions indicate that quasar ionization fronts…

Astrophysics · Physics 2008-11-26 Adam Lidz , Matthew McQuinn , Matias Zaldarriaga , Lars Hernquist , Suvendra Dutta

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 a new investigation of the intergalactic medium (IGM) near the end of reionization using "dark gaps" in the Lyman-alpha (Ly$\alpha$) forest. Using spectra of 55 QSOs at $z_{\rm em}>5.5$, including new data from the XQR-30 VLT…