English
Related papers

Related papers: ROHSA: Regularized Optimization for Hyper-Spectral…

200 papers

Hyperspectral images (HSIs) are often corrupted by a mixture of several types of noise during the acquisition process, e.g., Gaussian noise, impulse noise, dead lines, stripes, and many others. Such complex noise could degrade the quality…

Computer Vision and Pattern Recognition · Computer Science 2017-07-11 Yao Wang , Jiangjun Peng , Qian Zhao , Deyu Meng , Yee Leung , Xi-Le Zhao

We investigate a number of potential foregrounds for an ambitious goal of future radio telescopes such as the Square Kilometer Array (SKA) and Low Frequency Array (LOFAR): spatial tomography of neutral gas at high redshift in 21cm emission.…

Astrophysics · Physics 2009-11-07 S. Peng Oh , Katherine J. Mack

We study the formation of H2 in the ISM, using a modified version of the astrophysical magnetohydrodynamical code ZEUS-MP that includes a non-equilibrium treatment of the formation and destruction of H2. We examine two different…

Astrophysics · Physics 2008-11-26 S. C. O. Glover , M. -M. Mac Low

The neutral hydrogen 21cm line is potentially a very powerful probe of the observable universe, and a number of on-going experiments are trying to detect it at cosmological distances. However, the presence of strong foreground radiations…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Qizhi Huang , Fengquan Wu , Xuelei Chen

Cloud removal is an essential task in remote sensing data analysis. As the image sensors are distant from the earth ground, it is likely that part of the area of interests is covered by cloud. Moreover, the atmosphere in between creates a…

Computer Vision and Pattern Recognition · Computer Science 2022-10-06 Yi Guo , Feng Li , Zhuo Wang

Hyperspectral image (HSI) super-resolution is commonly used to overcome the hardware limitations of existing hyperspectral imaging systems on spatial resolution. It fuses a low-resolution (LR) HSI and a high-resolution (HR) conventional…

Image and Video Processing · Electrical Eng. & Systems 2021-04-27 Xiuheng Wang , Jie Chen , Qi Wei , Cédric Richard

We investigate the use of closure phase as a method to detect the HI 21cm signal from the neutral IGM during cosmic reionzation. Closure quantities have the unique advantage of being independent of antenna-based calibration terms. We employ…

Instrumentation and Methods for Astrophysics · Physics 2016-07-04 C. L. Carilli , P. Sims

We discuss the prospects for ``tomography'' of the intergalactic medium (IGM) at high redshifts using the 21 cm transition of neutral hydrogen. Existing observational constraints on the epoch of reionization imply a complex ionization…

Astrophysics · Physics 2009-11-10 Steven Furlanetto , Frank Briggs

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

Modelling the molecular gas that is routinely detected through CO observations of high-redshift galaxies constitutes a major challenge for ab initio simulations of galaxy formation. We carry out a suite of cosmological hydrodynamic…

Astrophysics of Galaxies · Physics 2020-09-04 Alexander Schäbe , Emilio Romano-Díaz , Cristiano Porciani , Aaron D. Ludlow , Matteo Tomassetti

In order to understand galaxy growth evolution, it is critical to constrain the evolution of its building block: gas. Mostly comprised by Hydrogen in its neutral (HI) and molecular (H2) phases, the latter is the one mostly directly…

Astrophysics of Galaxies · Physics 2024-02-12 Hugo Messias , Andrea Guerrero , Neil Nagar , Jack Regueiro , Violette Impellizzeri , Gustavo Orellana , Miguel Vioque

Distribution of cold gas in the post-reionization era provides an important link between distribution of galaxies and the process of star formation. Redshifted 21 cm radiation from the Hyperfine transition of neutral Hydrogen allows us to…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Bharat Kumar Gehlot , Jasjeet Singh Bagla

We have used the Arecibo telescope to carry out an survey of 31 dark clouds in the Taurus/Perseus region for narrow absorption features in HI ($\lambda$ 21cm) and OH (1667 and 1665 MHz) emission. We detected HI narrow self--absorption…

Astrophysics · Physics 2009-11-07 Di Li , Paul F. Goldsmith

The goal of this science case is to study physical conditions of the interstellar medium (ISM) in distant galaxies. In particular, its densest component is associated with the inner cores of clouds -- this is where star formation takes…

Astrophysics of Galaxies · Physics 2018-10-18 R. Decarli , C. Carilli , C. Casey , B. Emonts , J. A. Hodge , K. Kohno , D. Narayanan , D. Riechers , M. T. Sargent , F. Walter

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

We present the average rest-frame spectrum of high-redshift dusty, star-forming galaxies from 250-770GHz. This spectrum was constructed by stacking ALMA 3mm spectra of 22 such sources discovered by the South Pole Telescope and spanning…

Stars form in cold molecular clouds. However, molecular gas is difficult to observe because the most abundant molecule (H2) lacks a permanent dipole moment. Rotational transitions of CO are often used as a tracer of H2, but CO is much less…

We have created synthetic neutral hydrogen (HI) Galactic Plane Survey data cubes covering 90 degrees < l < 180 degrees, using a model spiral galaxy from SPH simulations and the radiative transfer code TORUS. The density, temperature and…

Astrophysics of Galaxies · Physics 2011-03-18 Kevin A. Douglas , David M. Acreman , Clare L. Dobbs , Christopher M. Brunt

The neutral atomic gas content of individual galaxies at large cosmological distances has until recently been difficult to measure due to the weakness of the hyperfine HI 21-cm transition. Here we estimate the HI gas mass of a sample of…

We use cosmological simulations of reionization to predict the effect of large HII regions around individual high-redshift quasars on the possible signal from the redshifted 21cm line of neutral hydrogen in the pre-reionization era. We show…

Astrophysics · Physics 2009-11-10 Katharina Kohler , Nickolay Y. Gnedin , Jordi Miralda-Escude , Peter A. Shaver