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Related papers: SKAO HI Intensity Mapping: Blind Foreground Subtra…

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We present in this paper a new Bayesian semi-blind approach for foreground removal in observations of the 21-cm signal with interferometers. The technique, which we call HIEMICA (HI Expectation-Maximization Independent Component Analysis),…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-20 Le Zhang , Emory F. Bunn , Ata Karakci , Andrei Korotkov , P. M. Sutter , Peter T. Timbie , Gregory S. Tucker , Benjamin D. Wandelt

We present here the results of a deep survey in a 0.4 sq.deg. blank field in Selected Area 57 conducted with the ISOPHOT instrument aboard ESAs Infrared Space Observatory (ISO) at both 60 um and 90 um. The resulting sky maps have a spatial…

In this work we present updated forecasts on parameterised modifications of gravity that can capture deviations of the behaviour of cosmological density perturbations beyond $\Lambda$CDM. For these forecasts we adopt the SKA Observatory…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-13 Santiago Casas , Isabella P. Carucci , Valeria Pettorino , Stefano Camera , Matteo Martinelli

Observations of the redshifted 21-cm signal emitted by neutral hydrogen represent a promising probe of large-scale structure in the universe. However, cosmological 21-cm signal is challenging to observe due to astrophysical foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Haochen Wang , Juan Mena-Parra , Tianyue Chen , Kiyoshi Masui

Unlike single image task, stereo image enhancement can use another view information, and its key stage is how to perform cross-view feature interaction to extract useful information from another view. However, complex noise in low-light…

Computer Vision and Pattern Recognition · Computer Science 2024-01-17 Minghua Zhao , Xiangdong Qin , Shuangli Du , Xuefei Bai , Jiahao Lyu , Yiguang Liu

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or…

Instrumentation and Methods for Astrophysics · Physics 2020-06-03 Suchetha Cooray , Tsutomu T. Takeuchi , Moe Yoda , Kazuo Sorai

Estimating depth from images nowadays yields outstanding results, both in terms of in-domain accuracy and generalization. However, we identify two main challenges that remain open in this field: dealing with non-Lambertian materials and…

Computer Vision and Pattern Recognition · Computer Science 2024-01-31 Pierluigi Zama Ramirez , Alex Costanzino , Fabio Tosi , Matteo Poggi , Samuele Salti , Stefano Mattoccia , Luigi Di Stefano

We construct a pipeline for simulating weak lensing cosmology surveys with the Square Kilometre Array (SKA), taking as inputs telescope sensitivity curves; correlated source flux, size and redshift distributions; a simple ionospheric model;…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-26 Anna Bonaldi , Ian Harrison , Stefano Camera , Michael L. Brown

We present a Bayesian framework to establish a power-spectrum space decomposition of frequency tomographic (PSDFT) data for future intensity mapping (IM) experiments. Different from most traditional component-separation methods which work…

Instrumentation and Methods for Astrophysics · Physics 2023-08-30 Chang Feng , Filipe B. Abdalla

This work presents the initial results of the drift-scan observation for the neutral hydrogen (HI) intensity mapping survey with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The data analyzed in this work were collected…

Line intensity mapping (LIM) is a promising tool to efficiently probe the three-dimensional large-scale structure by mapping the aggregate emission of a spectral line from all sources that trace the matter density field. Spectral lines from…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-09 Yun-Ting Cheng , Tzu-Ching Chang , James J. Bock

Diffuse Galactic emission at low frequencies is a major contaminant for studies of redshifted $21$ cm line studies. Removal of these foregrounds is essential for exploiting the signal from neutral hydrogen at high redshifts. Analysis of…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Sandeep Rana , Tuhin Ghosh , J. S. Bagla , Pravabati Chingangbam

We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 Azam Hussain , Shruti Thakur , Tapomoy Guha Sarkar , Anjan A Sen

The neutral hydrogen (HI) signal is a crucial probe for astrophysics and cosmology, but it is quite challenging to measure from raw data because of bright foreground contaminants at radio wavelengths. Cross-correlating the radio…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Alessandro Marins , Chang Feng , Filipe B. Abdalla

One of the major priorities of international radio astronomy is to study the early universe through the detection of the 21 cm HI line from the epoch of reionisation (EoR). Due to the weak nature of the 21 cm signal, an important part in…

Instrumentation and Methods for Astrophysics · Physics 2022-04-27 Michael A. Kriele , Randall B. Wayth , Mark J. Bentum , Budi Juswardy , Cathryn M. Trott

Neutral hydrogen (HI) will soon be the dark matter tracer observed over the largest volumes of Universe thanks to the 21 cm intensity mapping technique. To unveil cosmological information it is indispensable to understand the HI…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-06 Aurélie Pénin , Obinna Umeh , Mario Santos

Millimetre-wave observations represent an important tool for Cosmology studies. The Line Intensity Mapping (LIM) technique has been proposed to map in three dimensions the specific intensity due to line (e.g. [CII], CO) emission, for…

Instrumentation and Methods for Astrophysics · Physics 2023-08-29 Usasi Chowdhury , Florence Levy-Bertrand , Martino Calvo , Johannes Goupy , Alessandro Monfardini

Intensity mapping surveys will provide access to a coarse view of the cosmic large-scale structure in unprecedented large volumes at high redshifts. Given the large fractions of the sky that can be efficiently scanned using emission from…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-09 Oliver Leicht , Cora Uhlemann , Francisco Villaescusa-Navarro , Sandrine Codis , Lars Hernquist , Shy Genel

An improved method for subtracting contaminants from Cosmic Microwave Background (CMB) sky maps is presented, and used to estimate how well future experiments will be able to recover the primordial CMB fluctuations. We find that the naive…

Astrophysics · Physics 2015-06-24 Max Tegmark , George Efstathiou

Radio observation of the large-scale structure (LSS) of our Universe faces major challenges from foreground contamination, which is many orders of magnitude stronger than the cosmic signal. While other foreground removal techniques struggle…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-27 Tian-Cheng Luan , Xin Wang , Jiacheng Ding , Qian Li , Xiao-Dong Li , Weishan Zhu