English
Related papers

Related papers: $\mbox{H}$ $\mbox{I}$ 21-cm Absorption Spectra Cla…

200 papers

Rest-frame far-ultraviolet (FUV) observations from JWST are revolutionizing our understanding of the high-z galaxies that drove reionization and the mechanisms by which they accomplished it. To fully interpret these observations, we must be…

Compressed Learning (CL) is a joint signal processing and machine learning framework for inference from a signal, using a small number of measurements obtained by linear projections of the signal. In this paper we present an end-to-end deep…

Computer Vision and Pattern Recognition · Computer Science 2016-11-01 Amir Adler , Michael Elad , Michael Zibulevsky

All 21-cm signal experiments rely on electronic receivers that affect the data via both multiplicative and additive biases through the receiver's gain and noise temperature. While experiments attempt to remove these biases, the residuals of…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Keith Tauscher , David Rapetti , Bang D. Nhan , Alec Handy , Neil Bassett , Joshua Hibbard , David Bordenave , Richard F. Bradley , Jack O. Burns

In modern astrophysics, the machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We describe an application of the supervised…

Astrophysics of Galaxies · Physics 2018-12-26 Yu Bai , JiFeng Liu , Song Wang , Fan Yang

Understanding the first billion years of the universe requires studying two critical epochs: the Epoch of Reionization (EoR) and Cosmic Dawn (CD). However, due to limited data, the properties of the Intergalactic Medium (IGM) during these…

Instrumentation and Methods for Astrophysics · Physics 2024-10-18 Anshuman Tripathi , Gursharanjit Kaur , Abhirup Datta , Suman Majumdar

The atomic hydrogen HI content of galaxies is intimately related to star formation and galaxy evolution through the baryon cycle, which involves processes such as accretion, feedback, outflows, and gas recycling. While probing the HI gas…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-18 Sauraj Bharti , Ashish Kumar Meena , J. S. Bagla

We present a semi-analytic model for the Lyman-$\alpha$ forest that is inspired by the Halo Model. This model is built on the absorption line decomposition of the forest. Flux correlations are decomposed into those within each absorption…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-10 Vid Iršič , Matthew McQuinn

Many radio galaxies show the presence of dense and dusty gas near the active nucleus. This can be traced by both 21cm HI absorption and soft X-ray absorption, offering new insight into the physical nature of the circumnuclear medium of…

We use machine learning to classify galaxies according to their HI content, based on both their optical photometry and environmental properties. The data used for our analyses are the outputs in the range $z = 0-1$ from MUFASA cosmological…

Astrophysics of Galaxies · Physics 2020-02-05 Sambatra Andrianomena , Mika Rafieferantsoa , Romeel Davé

Ultraviolet absorption line spectroscopy is a sensitive diagnostic for the properties of interstellar and circumgalactic gas. Down-the-barrel observations, where the absorption is measured against the galaxy itself, are commonly used to…

Light curves serve as a valuable source of information on stellar formation and evolution. With the rapid advancement of machine learning techniques, it can be effectively processed to extract astronomical patterns and information. In this…

Instrumentation and Methods for Astrophysics · Physics 2025-03-18 Yu-Yang Li , Yu Bai , Cunshi Wang , Mengwei Qu , Ziteng Lu , Roberto Soria , Jifeng Liu

Overdense, metal-rich regions, shielded from stellar radiation might remain neutral throughout reionization and produce metal as well as 21 cm absorption lines. Simultaneous absorption from metals and 21 cm can complement each other as…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 Aniket Bhagwat , Benedetta Ciardi , Erik Zackrisson , Joop Schaye

We explore the application of computer vision and machine learning (ML) techniques to predict material properties (e.g. compressive strength) based on SEM images. We show that it's possible to train ML models to predict materials…

Galaxy disks are shown to contain a significant population of atomic clouds of 100pc linear size which are self-opaque in the 21cm transition. These objects have HI column densities as high as 10^23 and contribute to a global opacity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Robert Braun

Neutral atomic hydrogen and molecular gas in the host galaxies of radio active galactic nuclei (AGN) can be traced using H I 21-cm and OH-1667 MHz absorption lines to understand the fueling and feedback processes. We present the results of…

Astrophysics of Galaxies · Physics 2024-07-01 Yogesh Chandola , D. J. Saikia , Yin-Zhe Ma , Zheng Zheng , Chao-Wei Tsai , Di Li , Denis Tramonte , Hengxing Pan

High-number-density tracers of large-scale structure, such as the HI-rich galaxies measured by 21 cm intensity mapping, have low sampling noise, making them particularly promising as cosmological probes. At large scales, this sampling noise…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-28 Simon Foreman , Andrej Obuljen , Marko Simonović

We investigate the potential of machine learning (ML) methods to model small-scale galaxy clustering for constraining Halo Occupation Distribution (HOD) parameters. Our analysis reveals that while many ML algorithms report good statistical…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-19 Abhishek Jana , Lado Samushia

We have detected narrow HI 21cm and CI absorption at $z \sim 1.4 - 1.6$ towards Q0458$-$020 and Q2337$-$011, and use these lines to test for possible changes in the fine structure constant $\alpha$, the proton-electron mass ratio $\mu$, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 N. Kanekar , J. X. Prochaska , S. L. Ellison , J. N. Chengalur

We have used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to search for intervening 21 cm neutral hydrogen (HI) absorption along the line of sight to 53 bright radio continuum sources. Our observations are…

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

Astrophysics of Galaxies · Physics 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison
‹ Prev 1 8 9 10 Next ›