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Related papers: Lyalpha versus X-ray heating in the high-z IGM

200 papers

Lyman-$\alpha$ absorption systems at $z \sim 3$ with $N_{HI} \ga 3 \times 10^{14}$ cm$^{-2}$ have been found to be enriched with a mean metallicity of $Z/Z_{\odot} \sim 10^{-2.5}$, and a large scatter in the metallicity. It is reasonable to…

Astrophysics · Physics 2009-10-31 Biman Nath , Shiv Sethi , Yuri Shchekinov

Electrons densities in different locations of our galaxy are obtained in pulsar astronomy by dividing the dispersion measure (DM) by the distance of the pulsar to Earth. The properties of the interstellar plasma are related to its heating.…

High Energy Astrophysical Phenomena · Physics 2023-12-05 Y. Ben-Aryeh

The interstellar medium of galaxies, with temperatures reaching several million degrees, provides a pivotal perspective for understanding the physical and chemical properties of star formation, galactic evolution, and their associated…

Astrophysics of Galaxies · Physics 2025-06-24 Chunyi Zhang , Junfeng Wang

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

Unveiling the thermal history of the intergalactic medium (IGM) at $4 \leq z \leq 5$ holds the potential to reveal early onset HeII reionization or lingering thermal fluctuations from HI reionization. We set out to reconstruct the IGM gas…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-10 Fahad Nasir , Prakash Gaikwad , Frederick B. Davies , James S. Bolton , Ewald Puchwein , Sarah E. I. Bosman

Heating of neutral gas by energetic sources is crucial for the prediction of the 21 cm signal during the epoch of reionization (EoR). To investigate differences induced on statistics of the 21 cm signal by various source types, we use five…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 Qing-Bo Ma , Benedetta Ciardi , Marius B. Eide , Philipp Busch , Yi Mao , Qi-Jun Zhi

The observed relationship between X-ray luminosity and temperature of the diffuse intercluster medium clearly shows the effect of nongravitational heating on the formation of galaxy clusters. Quasar feedback into the intergalactic medium…

Astrophysics · Physics 2009-11-13 Suchetana Chatterjee , Arthur Kosowsky

We explore the effect of cosmic radiative feedback from the sources of reionization on the thermal evolution of the intergalactic medium. We find that different prescriptions for this feedback predict quite different thermal and…

Astrophysics · Physics 2008-06-26 R. Salvaterra , C. Burigana , R. Schneider , T. R. Choudhury , A. Ferrara , L. A. Popa

Little is currently known about the physical properties of the hot circumgalactic medium (CGM) surrounding massive galaxies. Next-generation X-ray observatories will enable detailed studies of the hot CGM in emission. To support these…

We derive constraints on the thermal and ionization states of the intergalactic medium (IGM) at redshift $\approx$ 9.1 using new upper limits on the 21-cm power spectrum measured by the LOFAR radio-telescope and a prior on the ionized…

Lyman-$\alpha$ (Ly$\alpha$) spectra provide insights into the small-scale structure and kinematics of neutral hydrogen (HI) within galaxies as well as the ionization state of the intergalactic medium (IGM). The former defines the intrinsic…

Astrophysics of Galaxies · Physics 2020-10-21 Chris Byrohl , Max Gronke

We derive the evolution of the energy deposition in the intergalactic medium (IGM) by dark matter (DM) decays/annihilations for both sterile neutrinos and light dark matter (LDM) particles. At z > 200 sterile neutrinos transfer a fraction…

Astrophysics · Physics 2008-11-26 E. Ripamonti , M. Mapelli , A. Ferrara

We investigate the role of cosmic rays from young galaxies in heating and ionizing the intergalactic medium (IGM) at high redshift. Using the IRAS observations at $60 \mu m$, we estimate the cosmic ray luminosity density at the present…

Astrophysics · Physics 2015-06-24 Biman B. Nath , Peter L. Biermann

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

The failure of purely gravitational models of X-ray cluster formation to reproduce basic observed properties of the local cluster population suggests the need for one or more additional physical processes operating on the intracluster…

Astrophysics · Physics 2009-10-31 John J. Bialek , August E. Evrard , Joseph J. Mohr

Collisional excitation of the 21cm HI hyperfine transition is not strong enough to thermalize it in warm neutral (``intercloud'') interstellar gas, which we show by simultaneously solving the equations of ionization and collisional…

Astrophysics · Physics 2009-11-06 H. Liszt

The emission of 21-cm radiation from a neutral intergalactic medium (IGM) at high redshift is discussed in connection with the thermal and ionization history of the universe. The physical mechanisms that make such radiation detectable…

Astrophysics · Physics 2009-10-31 Paolo Tozzi , Piero Madau , Avery Meiksin , Martin J. Rees

The ultraviolet background (UVB) emitted by quasars and galaxies governs the ionization and thermal state of the intergalactic medium (IGM), regulates the formation of high-redshift galaxies, and is thus a key quantity for modeling cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-20 Jose Oñorbe , Joseph F Hennawi , Zarija Lukić

The preheating of intergalactic medium(IGM) by structure collapsing and ultraviolet background(UVB) are investigated in cosmological hydrodynamical simulations. When gravitational collapsing is the sole heating mechanism, we find that (1)…

Astrophysics of Galaxies · Physics 2017-09-27 Weishan Zhu , Long-Long Feng

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The…