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Related papers: Modeling Post-Reionization HI Distributions in Fuz…

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A comprehensive analysis of 355 high-quality WSRT HI 21-cm line maps of nearby galaxies shows that the properties and incident rate of Damped Lyman-alpha (DLA) absorption systems observed in the spectra of high redshift QSOs are in good…

We present the study of CI/H$_2$ relative abundance in the diffuse cold neutral medium. Using the chemical and thermal balance model we calculated the dependence of CI/H$_2$ on the main parameters of the medium: hydrogen number density,…

Astrophysics of Galaxies · Physics 2024-02-02 Sergei Balashev , Daria Kosenko

We present the first results from our KODIAQ Z survey aimed to determine the metallicity distribution and physical properties of the z>2 partial and full Lyman limit systems (pLLSs and LLSs; 16.2<log N(HI)<19), which are probed of the…

Astrophysics of Galaxies · Physics 2016-12-28 Nicolas Lehner , John M. O'Meara , J. Christopher Howk , J. Xavier Prochaska , Michele Fumagalli

The low column density gas at the outskirts of galaxies as traced by the 21 cm hydrogen line emission (HI) represents the interface between galaxies and the intergalactic medium, i.e., where galaxies are believed to get their supply of gas…

Astrophysics of Galaxies · Physics 2018-05-23 Roger Ianjamasimanana , Fabian Walter , W. J. G. de Blok , George H. Heald , Elias Brinks

We present results of our HST Cycle 11 Survey for low-redshift (z<1.65) DLAs in the UV spectra of quasars selected from the SDSS Early Data Release. These quasars have strong intervening MgII-FeII systems which are known signatures of high…

Astrophysics · Physics 2009-11-13 Sandhya M. Rao , David A. Turnshek , Daniel. B. Nestor

Distribution of cold gas in the post-reionization era provides an important link between distribution of galaxies and the process of star formation. Redshifted 21 cm radiation from the Hyperfine transition of neutral Hydrogen allows us to…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Bharat Kumar Gehlot , Jasjeet Singh Bagla

We explore the imprints of fuzzy dark matter (FDM) on the redshifted 21~cm signal from the Cosmic Dawn and the Epoch of Reionization by employing the wavelet scattering transform (WST). FDM, composed of ultralight scalar particles with…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-02 Hayato Shimabukuro , Shihang Liu , Bohua Li

The fluctuations in the emission of redshifted 21cm photons from neutral inter-galactic hydrogen will provide an unprecedented probe of the reionization era. Conventional wisdom assumes that this 21cm signal disappears as soon as…

Astrophysics · Physics 2015-05-13 Stuart Wyithe , Abraham Loeb

We investigate the possibility of performing cosmological studies in the redshift range $2.5<z<5$ through suitable extensions of existing and upcoming radio-telescopes like CHIME, HIRAX and FAST. We use the Fisher matrix technique to…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-11 Andrej Obuljen , Emanuele Castorina , Francisco Villaescusa-Navarro , Matteo Viel

Extending the formalism of Datta, Bharadwaj & Choudhury (2007) for detecting ionized bubbles in redshifted 21 cm maps using a matched-filtering technique, we use different simulations to analyze the impact of HI fluctuations outside the…

Astrophysics · Physics 2009-11-13 Kanan K. Datta , Suman Majumdar , Somnath Bharadwaj , T. Roy Choudhury

We present a new, uniform analysis of the HI transmitted flux (F) and HI column density (N(HI)) distribution in the low-density IGM as a function of redshift z for 0<z<3.6 using 55 HST/COS FUV (Delta(z)=7.2 at z<0.5), five HST/STIS+COS NUV…

Galaxies in the early Universe were more compact and contained more molecular gas than today. In this paper, we revisit the relation between these empirical findings, and we quantitatively predict the cosmic evolution of the surface…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-09 Danail Obreschkow , Steve Rawlings

We use 85 pairs of high resolution LCDM cosmological simulations from the NIHAO project to investigate why in dwarf galaxies neutral hydrogen (HI) linewidths measured at 50% of the peak flux W_50 /2 (from the hydrodynamical simulations)…

Astrophysics of Galaxies · Physics 2018-11-28 Aaron A. Dutton , Aura Obreja , Andrea V. Macciò

We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the OverWhelmingly Large Simulations (OWLS) project. The base simulation includes…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-04 Gabriel Altay , Tom Theuns , Joop Schaye , Neil H. M. Crighton , Claudio Dalla Vecchia

An accurate method to measure the abundance of high-redshift galaxies consists in the observation of absorbers along the line of sight toward a background quasar. Here, we present abundance measurements of 13 z>3 sub-Damped Lyman-alpha…

Observations of damped Ly-alpha absorbers (DLA) indicate that the fraction of hydrogen in its neutral form (HI) is significant by mass at all redshifts. This gas represents the reservoir of material that is available for star formation at…

Astrophysics · Physics 2015-05-13 Stuart Wyithe

We introduce an efficient and accurate alternative to full hydrodynamic simulations, Hydro-PM (HPM), for the study of the low column density Lyman-alpha forest. It consists of a Particle-Mesh solver, modified to compute, in addition to the…

Astrophysics · Physics 2009-10-30 Nickolay Y. Gnedin , Lam Hui

A large fraction of baryons predicted from the standard cosmology has been missing observationally. Although previous numerical simulations have indicated that most of the missing baryons reside in large-scale filaments in the form of Warm…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Toshihiro Horii , Shinsuke Asaba , Kenji Hasegawa , Hiroyuki Tashiro

We measured metallicities for 33 z=3.4-4.2 absorption line systems drawn from a sample of H I-selected-Lyman limit systems (LLSs) identified in Sloan Digital Sky Survey (SDSS) quasar spectra and stratified based on metal line features. We…

Astrophysics of Galaxies · Physics 2017-01-09 Ana Glidden , Thomas J. Cooper , Kathy L. Cooksey , Robert A. Simcoe , John M. O'Meara

The Square Kilometre Array mid-frequency array will enable high-redshift detections of neutral hydrogen (HI) emission in galaxies, providing important constraints on the evolution of cold gas in galaxies over cosmic time. Strong…

Astrophysics of Galaxies · Physics 2024-09-12 Roger P. Deane , Tariq Blecher , Danail Obreschkow , Ian Heywood