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Related papers: Deep Learning the Intergalactic Medium using Lyman…

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We present a neural network emulator to constrain the thermal parameters of the intergalactic medium (IGM) at $\displaystyle{5.4}\le{z}\le{6.0}$ using the Lyman-$\displaystyle\alpha$ (Ly$\displaystyle\alpha$) forest flux auto-correlation…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Zhenyu Jin , Molly Wolfson , Joseph F. Hennawi , Diego González-Hernández

We develop an efficient method to study the effects of reionization history on the temperature-density relation of the intergalactic medium in the low density limit (overdensity less than 5). It is applied to the study of photo-reionization…

Astrophysics · Physics 2015-06-24 Lam Hui , Nickolay Y. Gnedin

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

The physical characteristics of the Lyman-alpha forest cloud systems are combined with observations on the baryonic mass density of the Universe and constraints from primordial nucleosynthesis to set boundary conditions on the Intergalactic…

Astrophysics · Physics 2007-05-23 Michael Fisher

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…

We investigate a method to determine the temperature-density relation of the intergalactic medium (IGM) at z~2-4 using quasar absorption line systems. Using a simple model combined with numerical simulations we show that there is a lower…

Astrophysics · Physics 2009-10-31 Greg L. Bryan , Marie E. Machacek

Numerical simulations indicate that the smooth, photoionized intergalactic medium (IGM) responsible for the low column density Lyman-alpha forest follows a well defined temperature-density relation. We show that such an equation of state…

Astrophysics · Physics 2007-05-23 Joop Schaye , Tom Theuns , Anthony Leonard , George Efstathiou

We publicly release a new sample of $34$ medium resolution quasar spectra at $5.77\leq z_{\rm em}\leq6.54$ observed with the Echellette Spectrograph and Imager (ESI) on the Keck telescope. This quasar sample represents an ideal laboratory…

Astrophysics of Galaxies · Physics 2018-09-05 Anna-Christina Eilers , Frederick B. Davies , Joseph F. Hennawi

We constrain the H I photoionization rate $(\Gamma_{\rm HI})$ at $z \lesssim 0.45$ by comparing the flux probability distribution function and power spectrum of the Ly-$\alpha$ forest data along 82 QSO sightlines obtained using Cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-28 Prakash Gaikwad , Vikram Khaire , Tirthankar Roy Choudhury , Raghunathan Srianand

Observations of the Lyman-$\alpha$ (Ly$\alpha$) forest in spectra of distant quasars enable us to probe the matter power spectrum at relatively small scales. With several upcoming surveys, it is expected that there will be a many-fold…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-15 Bhaskar Arya , Tirthankar Roy Choudhury , Aseem Paranjape , Prakash Gaikwad

Measurements of the intergalactic medium (IGM) temperature provide a potentially powerful constraint on the reionisation history due to the thermal imprint left by the photo-ionisation of neutral hydrogen. However, until recently IGM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Sudhir Raskutti , James S. Bolton , J. Stuart B. Wyithe , George D. Becker

The thermal history and structure of the intergalactic medium (IGM) at $z \geq 4$ is an important boundary condition for reionization, and a key input for studies using the Ly$\alpha$ forest to constrain the masses of alternative dark…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-19 Christopher Cain , Evan Scannapieco , Matthew McQuinn , Anson D'Aloisio , Hy Trac

The amplitude of fluctuations in the Ly-a forest on small spatial scales is sensitive to the temperature of the IGM and its spatial fluctuations. The temperature of the IGM and its spatial variations contain important information about…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Adam Lidz , C. -A. Faucher-Giguere , Aldo Dall'Aglio , Matthew McQuinn , Cora Fechner , Matias Zaldarriaga , Lars Hernquist , Suvendra Dutta

The temperature of the low-density intergalactic medium is set by the balance between adiabatic cooling resulting from the expansion of the universe, and photo-heating by the UV-background. A sudden injection of entropy from the…

Astrophysics · Physics 2007-05-23 Tom Theuns , Saleem Zaroubi , Tae-Sun Kim

Recent years have brought more precise temperature measurements of the low-density intergalactic medium (IGM). These new measurements constrain the processes that heated the IGM, such as the reionization of H I and of He II. We present a…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-10 Phoebe R. Upton Sanderbeck , Anson D'Aloisio , Matthew J. McQuinn

At redshifts z >~ 2, most of the baryons reside in the smooth intergalactic medium which is responsible for the low column density Lyman-alpha forest. This photoheated gas follows a tight temperature-density relation which introduces a…

Astrophysics · Physics 2009-10-31 Joop Schaye , Tom Theuns , Michael Rauch , George Efstathiou , Wallace L. W. Sargent

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

We introduce a new set of large scale, high resolution hydrodynamical simulations of the intergalactic medium: the Sherwood simulation suite. These are performed in volumes 10^3-160^3 h^-3 comoving Mpc^{3}, span almost four orders of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-07 James S. Bolton , Ewald Puchwein , Debora Sijacki , Martin G. Haehnelt , Tae-Sun Kim , Avery Meiksin , John A. Regan , Matteo Viel

During the epoch of reionization a large number of photons were produced with frequencies below the hydrogen Lyman limit. After redshifting into the closest resonance, these photons underwent multiple scatterings with atoms. We examine the…

Astrophysics · Physics 2008-11-26 Leonid Chuzhoy , Paul R. Shapiro

We compare cosmological hydrodynamical simulations combined with the homogeneous metagalactic UV background (UVB) of Haardt & Madau (2012) (HM2012) to observations of the Lyman-alpha forest that are sensitive to the thermal and ionization…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Ewald Puchwein , James S. Bolton , Martin G. Haehnelt , Piero Madau , George D. Becker , Francesco Haardt