English
Related papers

Related papers: Studying neutral hydrogen structures during the ep…

200 papers

A simple multifractal coarsening model is suggested that can explain the observed dynamical behavior of the fractal dimension in a wide range of coarsening fractal systems. It is assumed that the minority phase (an ensemble of droplets) at…

Disordered Systems and Neural Networks · Physics 2009-10-31 Avner Peleg , Baruch Meerson

Physical properties of the tiny scale structures in the cold neutral medium (CNM) of galaxies is a long-standing puzzle. Only a few lines of sights in our Galaxy have been studies with mixed results on the scale-invariant properties of such…

Astrophysics of Galaxies · Physics 2020-01-08 P. K. Vishwakarma , P. Dutta

The evolution of topology and morphology of ionized or neutral hydrogen during different stages of the Epoch of Reionization (EoR) have the potential to provide us a great amount of information about the properties of the ionizing sources…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 Aadarsh Pathak , Satadru Bag , Saswata Dasgupta , Suman Majumdar , Rajesh Mondal , Mohd Kamran , Prakash Sarkar

The spatial clustering properties of HI galaxies can be studied using the formalism of the halo occupation distribution (HOD). The resulting parameter constraints describe properties like gas richness verses environment. Unfortunately,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Stuart Wyithe , Michael J. I. Brown

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

Fractal structure of a system suggests the optimal way in which parts arranged or put together to form a whole. The ideas from fractals have a potential application to the researches on urban sustainable development. To characterize fractal…

Physics and Society · Physics 2016-09-27 Yanguang Chen

There are various notions of dimension in fractal geometry to characterise (random and non-random) subsets of $\mathbb R^d$. In this expository text, we discuss their analogues for infinite subsets of $\mathbb Z^d$ and, more generally, for…

Probability · Mathematics 2019-12-12 Markus Heydenreich

The neutral hydrogen (HI) power spectrum, measured from intensity fluctuations in the 21-cm background, offers insights into the large-scale structures (LSS) of our Universe in the post-reionization era (redshift $z<6$). A significant…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-10 Mohd Kamran , Martin Sahlén , Debanjan Sarkar , Suman Majumdar

Quantitative analysis of the structure of star clusters is crucial for understanding their formation and evolution. In this article, we explore the application of fractal dimension analysis to study the evolution of star clusters, also…

Astrophysics of Galaxies · Physics 2025-07-01 N. Ussipov , A. Akhmetali , M. Zaidyn , A. Akniyazova , A. Sakan , M. Kalambay , B. Shukirgaliyev

We present a review of the history and the present state of the fractal approach to the large-scale distribution of galaxies. Angular correlation function was used as a general instrument for the structure analysis. It was realized later…

Astrophysics · Physics 2007-05-23 Yurij Baryshev , Pekka Teerikorpi

On the one hand, the large scale structure of matter is arguably scale invariant, and, on the other hand, halos and voids are recognized as prominent features of that structure. To unify both approaches, we propose to model the dark matter…

Astrophysics · Physics 2008-11-26 Jose Gaite

Observations of intergalactic neutral hydrogen can provide a wealth of information about structure and galaxy formation, potentially tracing accretion and feedback processes on Mpc scales. Below a column density of NHI ~ 10^19 cm-2, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Attila Popping , Romeel Dave , Robert Braun , Benjamin D. Oppenheimer

The structure of the large scale distribution of the galaxies have been widely studied since the publication of the first catalogs. Since large redshift samples are available, their analyses seem to show fractal correlations up to the…

Astrophysics · Physics 2007-05-23 Marie-Noelle Celerier , Reuben Thieberger

Neutral hydrogen (HI) emission exhibits complex morphology that encodes rich information about the physics of the interstellar medium (ISM). We apply the scattering transform (ST) to characterize HI emission structure via a set of compact…

Astrophysics of Galaxies · Physics 2023-05-03 Minjie Lei , S. E. Clark

While the universe becomes more and more homogeneous at large scales, statistical analysis of galaxy catalogs have revealed a fractal structure at small-scales (\lambda < 100 h^{-1} Mpc), with a fractal dimension D=1.5-2 (Sylos Labini et al…

Astrophysics · Physics 2010-11-30 H. J. de Vega , N. Sánchez , F. Combes

We extend the results of previous analyses towards constraining the abundance and clustering of post-reionization ($z \sim 0-5$) neutral hydrogen (HI) systems using a halo model framework. We work with a comprehensive HI dataset including…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-23 Hamsa Padmanabhan , Alexandre Refregier , Adam Amara

Linear and nonlinear dissipative structures emerge in the irradiated single and multi walled carbon nano-tubes in the form of collision cascades and thermal spikes. These are diagnosed by the information theoretic tools of fractal dimension…

Mesoscale and Nanoscale Physics · Physics 2019-02-08 Shoaib Ahmad , Sumera Javeed

The 21 cm intensity mapping experiments promise to obtain the large-scale distribution of HI gas at the post-reionization epoch. In order to reveal the underlying matter density fluctuations from the HI mapping, it is important to…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-05 Zhenyuan Wang , Yangyao Chen , Yi Mao , Houjun Mo , Huiyuan Wang , Hong Guo , Cheng Li , Jian Fu , Yipeng Jing , Jing Wang , Xiaohu Yang , Zheng Zheng

We assess the impact of inhomogeneous reionization on detection of HII regions surrounding luminous high redshift quasars using planned low frequency radio telescopes. Our approach is to implement a semi-numerical scheme to calculate the…

Astrophysics · Physics 2017-07-24 Paul M. Geil , Stuart Wyithe

Gas velocity dispersions provide important diagnostics of the forces counteracting gravity to prevent collapse of the gas. We use the 21 cm line of neutral atomic hydrogen (HI) to study HI velocity dispersion and HI phases as a function of…

Astrophysics of Galaxies · Physics 2015-08-06 R. Ianjamasimanana , W. J. G. de Blok , Fabian Walter , George H. Heald , Anahi Caldu-Primo , Thomas H. Jarrett