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Related papers: Modeling HI at the field level

200 papers

Foreground removal is the most important step in detecting the large-scale redshifted HI 21-cm signal. Modelling foreground spectra is challenging and is further complicated by the chromatic response of the telescope. We present a…

Instrumentation and Methods for Astrophysics · Physics 2017-07-19 Visweshwar Ram Marthi , Suman Chatterjee , Jayaram Chengalur , Somnath Bharadwaj

Observations of the cosmic 21-cm power spectrum (PS) are starting to enable precision Bayesian inference of galaxy properties and physical cosmology, during the first billion years of our Universe. Here we investigate the impact of common…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 David Prelogović , Andrei Mesinger

Predicting the effects of physical perturbations on optical channels is critical for advanced photonic devices, but existing modelling techniques are often computationally intensive or require exhaustive characterisation. We present a novel…

Optics · Physics 2025-09-03 Joshua R. Jandrell , Mitchell A. Cox

Connecting numerical simulations to observations is essential to understanding the physics of galactic winds. Our Galaxy hosts a large-scale, multi-phase nuclear wind, whose dense gas has been detected using HI and molecular line…

Astrophysics of Galaxies · Physics 2024-12-12 Wladimir E. Banda-Barragán , Andrei Antipov , Daniel Villarruel

We compare the model power spectrum, computed based on perturbation theory (PT) with the power spectrum of luminous red galaxies (LRG) measured from the SDSSDR7 catalog, assuming a flat, CDM-dominated cosmology. The model includes the…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-21 Shun Saito , Masahiro Takada , Atsushi Taruya

Results of forward modelling of acoustic wave propagation in a realistic solar sub-photosphere with two cases of steady horizontal flows are presented and analysed by the means of local helioseismology. The simulations are based on fully…

Astrophysics · Physics 2009-11-13 S. Shelyag , R. Erdelyi , M. J. Thompson

Modelling the integrated H I spectra of galaxies has been a difficult task due to their diverse shapes, but more dynamical information is waiting to be explored in Hi line profiles. Based on simple assumptions, we construct a physically…

Astrophysics of Galaxies · Physics 2023-06-28 Bo Peng , Martha P. Haynes , Catie J. Ball , Michael G. Jones

Emission in spectral lines can provide unique information on interstellar turbulence. Doppler shifts due to supersonic motions contain information on turbulent velocity field which is otherwise difficult to measure. However, the problem of…

Astrophysics · Physics 2016-08-30 A. Lazarian

We build a bijective mapping between different physical fields from hydrodynamic CAMELS simulations. We train a CycleGAN on three different setups: translating dark matter to neutral hydrogen (Mcdm-HI), mapping between dark matter and…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Sambatra Andrianomena , Sultan Hassan , Francisco Villaescusa-Navarro

In preparation for the IGM tomography study by Subaru Prime Focus Spectrograph (PFS) survey and other large future telescopes such as TMT/ELT/GMT, we present the results of our pilot study on Ly$\alpha$ forest and IGM tomography statistics…

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for measuring the build-up of cosmological structure, which depends both on the expansion rate of the Universe and our theory of gravity.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Beth A. Reid , Martin White

We model, via Monte Carlo simulations, the distribution of observed U-B, B-V, V-I galaxy colors in the range 1.75<z<5 caused by variations in the line-of-sight opacity due to neutral hydrogen (HI). We also include HI internal to the source…

Astrophysics · Physics 2009-10-31 Matthew A. Bershady , Jane C. Charlton , Janet M. Geoffroy

Galaxy morphology in stellar light can be described by a series of "non-parametric" or "morphometric" parameters, such as concentration-asymmetry-smoothness, Gini, $M_{20}$, and Sersic fit. These parameters can be applied to column density…

Recently a number of analytic prescriptions for computing the non-linear matter power spectrum have appeared in the literature. These typically involve resummation or closure prescriptions which do not have a rigorous error control, thus…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Jordan Carlson , Martin White , Nikhil Padmanabhan

We present new multi-wavelength scaling relations between the neutral hydrogen content (HI) and the stellar properties of nearby galaxies selected from the HI Parkes All-Sky Survey (HIPASS). We use these new scaling relations to investigate…

Astrophysics of Galaxies · Physics 2015-06-22 Helga Dénes , Virginia A. Kilborn , Bärbel S. Koribalski

There is growing interest in using 3-dimensional neutral hydrogen mapping with the redshifted 21 cm line as a cosmological probe, as it has been argued to have a greater long-term potential than the cosmic microwave background. However, its…

Astrophysics · Physics 2008-11-26 Yi Mao , Max Tegmark , Matthew McQuinn , Matias Zaldarriaga , Oliver Zahn

The epoch of reionization is one of the least known chapters in the evolutionary history of the Universe. This thesis investigates two major approaches to unveil the reionization history of the Universe using HI 21-cm maps.The most…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-04 Kanan K. Datta

We study the effect of density fluctuations induced by turbulence on the HI/H$_2$ structure in photodissociation regions (PDRs) both analytically and numerically. We perform magnetohydrodynamic numerical simulations for both subsonic and…

Astrophysics of Galaxies · Physics 2017-07-26 Shmuel Bialy , Blakesley Burkhart , Amiel Sternberg

Blind cleaning methods are currently the preferred strategy for handling foreground contamination in single-dish HI intensity mapping surveys. Despite the increasing sophistication of blind techniques, some signal loss will be inevitable…

21-cm emission from neutral hydrogen during and before the epoch of cosmic reionisation is gravitationally lensed by material at all lower redshifts. Low-frequency radio observations of this emission can be used to reconstruct the projected…

Astrophysics · Physics 2009-06-25 Stefan Hilbert , R. Benton Metcalf , S. D. M. White