English
Related papers

Related papers: Deep learning approach for identification of HII r…

200 papers

The upcoming Square Kilometre Array (SKA-Low) will map the distribution of neutral hydrogen during reionization, and produce a tremendous amount of 3D tomographic data. These images cubes will be subject to instrumental limitations, such as…

Instrumentation and Methods for Astrophysics · Physics 2021-06-25 Michele Bianco , Sambit. K. Giri , Ilian T. Iliev , Garrelt Mellema

The low-frequency component of the upcoming Square Kilometre Array Observatory (SKA-Low) will be sensitive enough to construct 3D tomographic images of the 21-cm signal distribution during reionisation. However, foreground contamination…

We seek to remove foreground contaminants from 21cm intensity mapping observations. We demonstrate that a deep convolutional neural network (CNN) with a UNet architecture and three-dimensional convolutions, trained on simulated…

Upcoming experiments will map the spatial distribution of the 21-cm signal over three-dimensional volumes of space during the Epoch of Reionization (EoR). Several methods have been proposed to mitigate the issue of astrophysical foreground…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-30 Jacob Kennedy , Jonathan Colaço Carr , Samuel Gagnon-Hartman , Adrian Liu , Jordan Mirocha , Yue Cui

A number of current and future experiments aim to detect the reionization of neutral hydrogen by the first stars and galaxies in the Universe via the redshifted 21cm line. Using the \textsc{BlueTides} simulation, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-20 James E Davies , Rupert A. Croft , Tiziana Di-Matteo , Bradley Greig , Yu Feng , Stuart Wyithe

Measuring the properties of the intergalactic medium (IGM) and sources during the Epoch of Reionization (EoR) is of immense importance. We explore the prospects of probing the IGM and sources through redshifted 21-cm observations of…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-24 Arnab Mishra , Chandra Shekhar Murmu , Kanan K. Datta , Samir Choudhuri , Suman Majumdar , Iffat Nasreen , Sk. Saiyad Ali

Upcoming 21cm surveys with the SKA1-LOW telescope will enable imaging of the neutral hydrogen distribution on cosmological scales in the early Universe. These surveys are expected to generate huge imaging datasets that will encode more…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-22 Tumelo Mangena , Sultan Hassan , Mario G. Santos

Active Galactic Nuclei (AGN) and star-forming galaxies are leading candidates for being the luminous sources that reionized our Universe. Next-generation 21cm surveys are promising to break degeneracies between a broad range of reionization…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-20 Sultan Hassan , Adrian Liu , Saul Kohn , Paul La Plante

Detecting and characterizing individual ionized bubbles during the Epoch of Reionization (EoR) using the redshifted HI 21-cm signal provides a direct probe of the early ionizing sources and the intergalactic medium. We develop and validate…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-07 Arnab Mishra , Kanan Kumar Datta , Chandra Shekhar Murmu , Samir Choudhuri , Iffat Nasreen , Snehasish Saha

Upcoming measurements of the high-redshift 21 cm signal from the Epoch of Reionization (EoR) are a promising probe of the astrophysics of the first galaxies and of cosmological parameters. In particular, the optical depth $\tau$ to the last…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-29 Tashalee S. Billings , Paul La Plante , James E. Aguirre

Aiming to correctly restore the redshifted 21 cm signals emitted by the neutral hydrogen during the cosmic reionization processes, we re-examine the separation approaches based on the quadratic polynomial fitting technique in frequency…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jingying Wang , Haiguang Xu , Tao An , Junhua Gu , Xueying Guo , Weitian Li , Yu Wang , Chengze Liu , Olivier Martineau-Huynh , Xiang-Ping Wu

Upcoming 21-cm intensity surveys will use the hyperfine transition in emission to map out neutral hydrogen in large volumes of the universe. Unfortunately, large spatial scales are completely contaminated with spectrally smooth…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-27 Chirag Modi , Martin White , Anze Slosar , Emanuele Castorina

The deep learning technique has been employed in removing foreground contaminants from 21 cm intensity mapping, but its effectiveness is limited by the large dynamic range of the foreground amplitude. In this study, we develop a novel…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-13 Feng Shi , Haoxiang Chang , Le Zhang , Huanyuan Shan , Jiajun Zhang , Suiping Zhou , Ming Jiang , Zitong Wang

The 21-cm intensity mapping (IM) of neutral hydrogen (HI) is a promising tool to probe the large-scale structures. Sky maps of 21-cm intensities can be highly contaminated by different foregrounds, such as Galactic synchrotron radiation,…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Elimboto Yohana , Yin-Zhe Ma , Di Li , Xuelei Chen , Wei-Ming Dai

One of the critical challenges facing imaging studies of the 21-cm signal at the Epoch of Reionization (EoR) is the separation of astrophysical foreground contamination. These foregrounds are known to lie in a wedge-shaped region of…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Samuel Gagnon-Hartman , Yue Cui , Jacob Kennedy , Adrian Liu , Siamak Ravanbakhsh

Next-generation 21cm observations will enable imaging of reionization on very large scales. These images will contain more astrophysical and cosmological information than the power spectrum, and hence providing an alternative way to…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-27 Sultan Hassan , Adrian Liu , Saul Kohn , James E. Aguirre , Paul La Plante , Adam Lidz

The 21 cm intensity mapping provides a promising probe of the large-scale structure. Astrophysical foregrounds, as the main source of contamination to the cosmological 21 cm signal, persist in a wedge-like region of Fourier space due to the…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-04 Kaifeng Yu , Xin Wang

Observing the neutral hydrogen distribution across the Universe via redshifted 21cm line intensity mapping constitutes a powerful probe for cosmology. However, the redshifted 21cm signal is obscured by the foreground emission from our…

Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 F. Mertens , A. Ghosh , L. V. E. Koopmans

Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Nithyanandan Thyagarajan , Chris Carilli , Bojan Nikolic
‹ Prev 1 2 3 10 Next ›