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

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We present a new statistical tool, called the triangle correlation function (TCF), inspired by the earlier work of Obreschkow et al. It is derived from the three-point correlation function and aims to probe the characteristic scale of…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Adélie Gorce , Jonathan R. Pritchard

The ionisation structure of the Intergalactic Medium (IGM) during reionisation is sensitive to the unknown galaxy formation physics that prevailed at that time. This structure introduces non-Gaussian statistics into the redshifted 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-20 Stuart Wyithe , Paul M. Geil , Hansik Kim

We describe a new algorithm for including the dynamical effects of ionizing radiation in SPH simulations, and we present several examples of how the algorithm can be applied to problems in star formation. We use the HEALPix software to…

Solar and Stellar Astrophysics · Physics 2009-11-13 T. G. Bisbas , R. Wunsch , A. P. Whitworth , D. A. Hubber

We use a set of semi-numerical simulations based on Zel'dovich approximation, friends-of-friends algorithm and excursion set formalism to generate reionization maps of high dynamic range with a range of assumptions regarding the…

Astrophysics · Physics 2009-11-13 T. Roy Choudhury , M. G. Haehnelt , J. Regan

Recently, there has been a great deal of interest in understanding the reionization of hydrogen in the intergalactic medium (IGM). One of the major outstanding questions is how this event proceeds on large scales. Motivated by numerical…

Astrophysics · Physics 2009-11-10 Steven Furlanetto , Matias Zaldarriaga , Lars Hernquist

One of the key observables of the reionization era is the distribution of neutral and ionized gas. Recently, Furlanetto, Zaldarriaga, & Hernquist developed a simple analytic model to describe the growth of HII regions during this era. Here,…

Astrophysics · Physics 2009-11-13 Steven R. Furlanetto , Matthew McQuinn , Lars Hernquist

The propagation of cosmological ionization fronts (I-fronts) during reionization is strongly influenced by small-scale structure. Here we summarize our recent attemps to understand the effect of this small-scale structure. We present high…

Morphology of the complex HI gas distribution can be quantified by statistics like the Minkowski functionals, and can provide a way to statistically study the large scale structure in the HI maps both at low redshifts, and during the epoch…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-19 Yougang Wang , Yidong Xu , Fengquan Wu , Xuelei Chen , Xin Wang , Juhan Kim , Changbom Park , Khee-Gan Lee , Renyue Cen

We present a new formalism for studying the topology of HII regions during the Epoch of Reionisation, based on persistent homology theory. With persistent homology, it is possible to follow the evolution of topological features over time.…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-10 Willem Elbers , Rien van de Weygaert

We study the formation and evolution of HII regions around the first stars formed at z=10-30. We use a one-dimensional Lagrangian hydrodynamics code which self-consistently incorporates radiative transfer and non-equilibrium primordial gas…

Astrophysics · Physics 2009-11-10 T. Kitayama , N. Yoshida , H. Susa , M. Umemura

We present an improved matched filter method for detecting large ionized regions in 21 cm observations of the Epoch of Reionization. In addition to detection, the method constrains the properties of these regions, offering insights into the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-23 Rutvik Ashish Mahajan , Raghunath Ghara , Nishant Pradeep Deo , Arnab Mishra

The distribution of ionised hydrogen during the epoch of reionization (EoR) has a complex morphology. We propose to measure the three-dimensional topology of ionised regions using the Betti numbers. These quantify the topology using the…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-25 Sambit K. Giri , Garrelt Mellema

We introduce a versatile and spatially resolved morphological characterisation of binary fields, rooted in the opening transform of mathematical morphology. We subsequently apply it to the thresholded ionization field in simulations of…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-08 Philipp Busch , Marius B. Eide , B. Ciardi , Koki Kakiichi

We study the evolution of the hydrogen ionization field during the epoch of reionization (EoR) using semi-numerical simulations. By calculating the Minkowski functionals (MFs) of the 21cm brightness temperature field, which provides a…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-14 Zhaoting Chen , Yidong Xu , Yougang Wang , Xuelei Chen

We present a spatially-resolved HII region study of the gas-phase metallicity, ionization parameter, and ISM pressure maps of 6 local star-forming and face-on spiral galaxies from the TYPHOON program. Self-consistent metallicity, ionization…

We present semi-analytic models of the epoch of reionization focusing on the differences between continuous and bursty star formation (SF). Our model utilizes physically motivated analytic fits to 1D radiative transfer simulations of HII…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Blake Hartley , Massimo Ricotti

Minkowski functionals and Shapefinders shed light on the connectedness of large-scale structure by determining its topology and morphology. We use a sophisticated code, SURFGEN2, to measure the Minkowski functionals and Shapefinders of…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-30 Satadru Bag , Rajesh Mondal , Prakash Sarkar , Somnath Bharadwaj , Tirthankar Roy Choudhury , Varun Sahni

We investigate the possibility of constraining the ionization state of the intergalactic medium (IGM) close to the end of reionization (z ~ 6) by measuring the size of the HII regions in high-z quasars spectra. We perform a combination of…

Astrophysics · Physics 2008-11-26 A. Maselli , S. Gallerani , A. Ferrara , T. R. Choudhury

The bubble size distribution of ionized hydrogen regions probes the information about the morphology of \HII\ bubbles during the reionization. Conventionally, the \HII\ bubble size distribution can be derived from the tomographic imaging…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-15 Hayato Shimabukuro , Yi Mao , Jianrong Tan

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