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Related papers: Topology and Sizes of HII Regions during Cosmic Re…

200 papers

The ability of the future low frequency component of the Square Kilometre Array radio telescope (SKA-Low) to produce tomographic images of the redshifted 21-cm signal will enable direct studies of the evolution of the sizes and shapes of…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-06 Sambit K. Giri , Garrelt Mellema , Raghunath Ghara

We use group size haloes identified with a ``friends of friends'' (FOF) algorithm in a concordance $\Lambda \rm{CDM}$ GADGET2 (dark matter only) simulation to investigate the dependence of halo properties on the environment at $z=0$. The…

Astrophysics · Physics 2008-11-26 Cinthia Ragone-Figueroa , Manolis Plionis

We present a set of photoionization models that reproduce simultaneously the observed optical and mid-infrared spatial distribution of the HII region NGC595 in the disk of M33 using the code CLOUDY. Both optical (PMAS-Integral Field…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Enrique Perez-Montero , Monica Relano , Jose M. Vilchez , Ana Monreal-Ibero

We describe a new methodology to analyze the reionization process in numerical simulations: The evo- lution of the reionization is investigated by focusing on the merger histories of individual HII regions. From the merger tree of ionized…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-10 Jonathan Chardin , Dominique Aubert

We explore the impact of reionization topology on 21-cm statistics. Four reionization models are presented which emulate large ionized bubbles around over-dense regions (21CMFAST/ global-inside- out), small ionized bubbles in over-dense…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-15 Catherine A. Watkinson , Jonathan R. Pritchard

Observations of the epoch of reionization give us clues about the nature and evolution of the sources of ionizing photons, or early stars and galaxies. We present a new suite of structure formation and radiative transfer simulations from…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Keri L. Dixon , Ilian T. Iliev , Garrelt Mellema , Kyungjin Ahn , Paul R. Shapiro

Scale-invariant morphology parameters applied to atomic hydrogen maps (HI) of galaxies can be used to quantify the effects of tidal interaction or star-formation on the ISM. Here we apply these parameters, Concentration, Asymmetry,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 B. W. Holwerda , N. Pirzkal , W. J. G. de Blok , S-L. Blyth

By depleting the ionizing photon budget available to expand cosmic HII regions, recombining systems (or Lyman limit systems) can have a large impact during (and following) cosmic reionization. Unfortunately, directly resolving such…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Emanuele Sobacchi , Andrei Mesinger

We present a new method for modeling inhomogeneous cosmic reionization on large scales. Utilizing high-resolution radiation-hydrodynamic simulations with 2048^3 dark matter particles, 2048^3 gas cells, and 17 billion adaptive rays in a L =…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Nick Battaglia , Hy Trac , Renyue Cen , Abraham Loeb

Simulating the distribution of cosmological neutral hydrogen (HI) during the epoch of reionization requires a high dynamic range and is hence computationally expensive. The size of the simulation is dictated by the largest scales one aims…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Ankur Barsode , Tirthankar Roy Choudhury

Searches for Lyman-alpha emission lines are among the most effective ways to identify high-redshift galaxies. They are particularly interesting because they probe not only the galaxies themselves but also the ionization state of the…

Astrophysics · Physics 2009-11-13 Steven R. Furlanetto , Matias Zaldarriaga , Lars Hernquist

We use optical integral field spectroscopy and 8 and 24 micron mid-IR observations of the giant HII region NGC 588 in the disc of M33 as input and constraints for two-dimensional tailor-made photoionisation models. Two different geometrical…

We present a new hybrid code for large volume, high resolution simulations of cosmic reionization, which utilizes a N-body algorithm for dark matter, physically motivated prescriptions for baryons and star formation, and an adaptive ray…

Astrophysics · Physics 2009-11-11 Hy Trac , Renyue Cen

In this paper, we propose an Alcock-Paczy\'nski (AP) test to constrain cosmology using HII bubbles during the Epoch of Reionization. Similarly to cosmic voids, a stack of HII bubbles is spherically symmetric because ionizing fronts…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-04 Emilie Thélie , Franco Del Balso , Julian B. Muñoz , Adrian Liu

I use cosmological simulations that incorporate a physically motivated approximation to three-dimensional radiative transfer that recovers correct asymptotic ionization front propagation speeds for some cosmologically relevant density…

Astrophysics · Physics 2009-10-31 Nickolay Y. Gnedin

We present a method to construct semi-numerical ``simulations'', which can efficiently generate realizations of halo distributions and ionization maps at high redshifts. Our procedure combines an excursion-set approach with first-order…

Astrophysics · Physics 2009-11-13 Andrei Mesinger , Steven Furlanetto

We present a study of the impact of a bright quasar on the redshifted 21cm signal during the Epoch of Reionization (EoR). Using three different cosmological radiative transfer simulations, we investigate if quasars are capable of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Kanan K. Datta , Martina M. Friedrich , Garrelt Mellema , Ilian T. Iliev , Paul R. Shapiro

We use the Dark-ages, Reionization And Galaxy-formation Observables from Numerical Simulations (DRAGONS) framework to investigate the effect of galaxy-formation physics on the morphology and statistics of ionized hydrogen (HII) regions…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-24 Paul M. Geil , Simon J. Mutch , Gregory B. Poole , Paul W. Angel , Alan R. Duffy , Andrei Mesinger , J. Stuart B. Wyithe

The James Webb Space Telescope (JWST) is discovering an increasing number of galaxies well into the early stages of the Epoch of Reionization (EoR). Many of these galaxies are clustered with strong Lyman alpha (Ly$\alpha$) emission,…

Galaxy evolution is driven to a large extent by interactions and mergers with other galaxies and the gas in galaxies is extremely sensitive to the interactions. One method to measure such interactions uses the quantified morphology of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 B. W. Holwerda , N. Pirzkal , W. J. G. de Blok , A. Bouchard , S-L. Blyth , K. J. van der Heyden , E. C. Elson