English
Related papers

Related papers: Reionization constraints using Principal Component…

200 papers

We present the results of a study to optimize the principal component analysis (PCA) algorithm for planet detection, a new algorithm complementing ADI and LOCI for increasing the contrast achievable next to a bright star. The stellar PSF is…

Earth and Planetary Astrophysics · Physics 2015-06-17 T. Meshkat , M. Kenworthy , S. P. Quanz , A. Amara

The fraction of ionizing photons (fesc) that escape from z>6 galaxies is an important parameter when assessing the role of these objects in the reionization of the Universe, but the opacity of the intergalactic medium precludes a direct…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 E. Zackrisson , A. K. Inoue , H. Jensen

We present new upper limits on the volume-weighted neutral hydrogen fraction, <xHI>, at z~5-6 derived from spectroscopy of bright quasars. The fraction of the Lyman-alpha and Lyman-beta forests that is "dark" (with zero flux) provides the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Ian McGreer , Andrei Mesinger , Valentina D'Odorico

We use the photon flux and absorption tracer algorithm presented in Katz et al.~2018, to characterise the contribution of haloes of different mass and stars of different age and metallicity to the reionization of the Universe. We employ a…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-05 Harley Katz , Taysun Kimm , Martin G. Haehnelt , Debora Sijacki , Joakim Rosdahl , Jeremy Blaizot

We provide an update on the constraints on extended reionization histories with the Planck 2018 cosmic microwave background anisotropy data. The Planck 2018 data on large angular scales improve the measurement of the $E$-mode polarization…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Daniela Paoletti , Dhiraj Kumar Hazra , Fabio Finelli , George F. Smoot

The Wilkinson Microwave Anisotropy Probe (WMAP) experiment has detected reionization at the $5.5 \sigma$ level and has reported a mean optical depth of $0.088 \pm 0.015$. A powerful probe of reionization is the large-angle $EE$ polarization…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Aravind Natarajan , Dominik J. Schwarz

We explore the constraints on the history of reionization from Planck 2015 Cosmic Microwave Background (CMB) data and we derive the forecasts for future CMB observations. We consider a class of monotonic histories of reionization as…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Dhiraj Kumar Hazra , Daniela Paoletti , Fabio Finelli , George F. Smoot

Lyman-$\alpha$ (Ly$\alpha$) emitting galaxies are powerful tools to probe the late stages of cosmic reionization. The observed sudden drop in Ly$\alpha$ fraction at $z>6$ is often interpreted as a sign of reionization, since the…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 Sultan Hassan , Max Gronke

The Laser Interferometer Space Antenna (LISA) will provide us with a unique opportunity to observe the early inspiral phase of supermassive binary black holes (SMBBHs) in the mass range of $10^5-10^6\,M_{\odot}$, that lasts for several…

General Relativity and Quantum Cosmology · Physics 2023-03-09 Sayantani Datta

We use a suite of cosmological hydrodynamic simulations including a self-consistent treatment for inhomogeneous reionisation to study the impact of galactic outflows and photoionisation heating on the volume-averaged recombination rate of…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 K. Finlator , S. Peng Oh , F. Özel , R. Davé

We present predictions drawn from cosmological hydrodynamic simulations for the physical, photometric and emission line properties of galaxies present during the latter stages of reionization from z=9-6. We find significant numbers of…

Astrophysics · Physics 2009-11-11 Romeel Davé , Kristian Finlator , Benjamin D. Oppenheimer

We examine the constraints on soft X-ray emissions from the reionization era. It has generally been assumed that the Universe was reionized by ultraviolet photons from massive stars. However, it has been argued that X-ray photons associated…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Matthew McQuinn

A model of the density distribution in the intergalactic medium, motivated by that found in numerical simulations, is used to demonstrate the effect of a clumpy IGM and discrete sources on the reionization of the universe. In an…

Astrophysics · Physics 2009-10-31 Jordi Miralda-Escude , Martin Haehnelt , Martin J. Rees

We show that numerical simulations of reionization that resolve the Lyman Limit systems (and, thus, correctly count absorptions of ionizing photons) have converged to about 10% level for 5<z<6.2 and are in reasonable agreement (within 10%)…

Astrophysics · Physics 2010-11-11 Nickolay Y. Gnedin , Xiaohui Fan

In this paper, we implement Principal Component Analysis (PCA) to study the single particle distributions generated from thousands of {\tt VISH2+1} hydrodynamic simulations with an aim to explore if a machine could directly discover flow…

Nuclear Theory · Physics 2020-01-08 Ziming Liu , Wenbin Zhao , Huichao Song

Recently, NIRSpec PRISM/CLEAR observations by JWST have begun providing rest-frame UV continuum measurements of galaxies at $z\gtrsim7$, revealing signatures of Ly$\alpha$ damping-wing (DW) absorption by the intergalactic medium (IGM). We…

The study of the Luminosity Function (LF) of Lyman Break Galaxies (LBGs) at z=7 is important for ascertaining their role in the reionization of the Universe. We perform a detailed and critical analysis of the statistical and systematic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 A. Grazian , M. Castellano , A. M. Koekemoer , A. Fontana , L. Pentericci , V. Testa , K. Boutsia , E. Giallongo , M. Giavalisco , P. Santini

In a semi-numerical model of reionization, the evolution of ionization fraction is simulated approximately by the ionizing photon to baryon ratio criterion. In this paper we incorporate a semi-analytical model of galaxy formation based on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jie Zhou , Qi Guo , Gaochao Liu , Bin Yue , Yidong Xu , Xuelei Chen

Searching for departures from general relativity (GR) in more than one post-Newtonian (PN) phasing coefficients, called a \emph{multi-parameter test}, is known to be ineffective given the sensitivity of the present generation of…

General Relativity and Quantum Cosmology · Physics 2022-05-11 Muhammed Saleem , Sayantani Datta , K. G. Arun , B. S. Sathyaprakash

We present the first characterization of the Gunn-Peterson trough in high-redshift galaxies using public JWST NIRSpec spectroscopy. This enables us to derive the first galaxy-based IGM opacity measurements at the end of reionisation. Using…

Astrophysics of Galaxies · Physics 2025-09-03 Romain A. Meyer , Guido Roberts-Borsani , Pascal Oesch , Richard S. Ellis