English
Related papers

Related papers: Correlation-based Beam Calibration of 21cm Intensi…

200 papers

We present the first application of a new foreground removal pipeline to the current leading HI intensity mapping dataset, obtained by the Green Bank Telescope (GBT). We study the 15hr and 1hr field data of the GBT observations previously…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-18 L. Wolz , C. Blake , F. B. Abdalla , C. M. Anderson , T. -C. Chang , Y. -C. Li , K. W. Masui , E. Switzer , U. -L. Pen , T. C. Voytek , J. Yadav

Observations of 21cm line from neutral hydrogen promise to be an exciting new probe of astrophysics and cosmology during the Cosmic Dawn and through the Epoch of Reionization (EoR) to when dark energy accelerates the expansion of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-24 Tyler A. Cox , Aaron R. Parsons , Joshua S. Dillon , Aaron Ewall-Wice , Robert Pascua

Hyperspectral cameras have recently been miniaturized for operation on lightweight airborne platforms such as UAV or small aircraft. Unlike frame cameras (RGB or Multispectral), many hyperspectral sensors use a linear array or 'push-broom'…

Computer Vision and Pattern Recognition · Computer Science 2024-09-11 Julien Yuuki Burkhard , Jesse Ray Murray Lahaye , Laurent Valentin Jospin , Jan Skaloud

Multiexponential modeling of relaxation or diffusion MR signal decays is a popular approach for estimating and spatially mapping different microstructural tissue compartments. While this approach can be quite powerful, it is also limited by…

Image and Video Processing · Electrical Eng. & Systems 2019-05-10 Daeun Kim , Jessica L. Wisnowski , Christopher T. Nguyen , Justin P. Haldar

Line intensity mapping (LIM) serves as a potent probe in astrophysics, relying on the statistical analysis of integrated spectral line emissions originating from distant star-forming galaxies. While LIM observations hold the promise of…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Anirban Roy , Nicholas Battaglia

This study presents a nonlinear signal processing method for accurate radar-based heartbeat interval estimation by exploiting the periodicity of higher-order harmonics inherent in heartbeat signals. Unlike conventional approaches that…

Signal Processing · Electrical Eng. & Systems 2025-07-29 Kohei Shimomura , Chi-Hsuan Lee , Takuya Sakamoto

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…

Line-intensity mapping (IM) experiments seek to perform statistical measurements of large-scale structure with spectral lines such as 21cm, CO, and Lyman-$\alpha$ (Ly$\alpha$). A challenge in these observations is to ensure that…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-11 Eli Visbal , Matthew McQuinn

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

The sky-averaged, or global, background of redshifted $21$ cm radiation is expected to be a rich source of information on cosmological reheating and reionizaton. However, measuring the signal is technically challenging: one must extract a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-03 Tejaswi Venumadhav , Tzu-Ching Chang , Olivier Doré , Christopher M. Hirata

Ramsey interferometry is a widely used tool for precisely measuring transition frequencies between two energy levels of a quantum system, with applications in time-keeping, precision spectroscopy, quantum optics, and quantum information.…

Quantum Physics · Physics 2023-02-21 H. Hainzer , D. Kiesenhofer , T. Ollikainen , M. Bock , F. Kranzl , M. K. Joshi , G. Yoeli , R. Blatt , T. Gefen , C. F. Roos

Systematic effects that limit the achievable sensitivity of current low-frequency radio telescopes to the 21 cm signal are among the foremost challenges in observational 21 cm cosmology. The standard approach to retrieving the 21 cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 S. Munshi , L. V. E. Koopmans , F. G. Mertens , A. R. Offringa , S. A. Brackenhoff , E. Ceccotti , J. K. Chege , L. Y. Gao , S. Ghosh , M. Mevius , S. Zaroubi

The success of HI intensity mapping is largely dependent on how well 21cm foreground contamination can be controlled. In order to progress our understanding further, we present a range of simulated foreground data from four different…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-25 Steven Cunnington , Melis O. Irfan , Isabella P. Carucci , Alkistis Pourtsidou , Jérôme Bobin

A new generation of interferometric instruments is emerging which aim to use intensity mapping of redshifted $21\,$cm radiation to measure the large-scale structure of the Universe at $z\simeq 1-2$ over wide areas of sky. While these…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Martin White , Nikhil Padmanabhan

It is well-known that foreground subtraction in 21cm surveys removes large scale power. We investigate associated systematic biases. We show that removing line-of-sight fluctuations on large scales aliases into suppression of the 3D power…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Nada Petrovic , S. Peng Oh

Hyperspectral imaging aims at providing information on both the spatial and the spectral distribution of light, with high resolution. However, state-of-the-art protocols are characterized by an intrinsic trade-off imposing to sacrifice…

Optics · Physics 2024-07-22 Gianlorenzo Massaro , Francesco V. Pepe , Milena D'Angelo

In future linear colliders the luminosity will depend on maintaining the small emittance aspect ratio delivered by damping rings. Correction of cross-plane coupling can be important in preventing dilution of the beam emittance. In order to…

Accelerator Physics · Physics 2007-05-23 M. D. Woodley , P. E. Emma

Existing single-image denoising algorithms often struggle to restore details when dealing with complex noisy images. The introduction of near-infrared (NIR) images offers new possibilities for RGB image denoising. However, due to the…

Computer Vision and Pattern Recognition · Computer Science 2025-03-25 Yuchen Wang , Hongyuan Wang , Lizhi Wang , Xin Wang , Lin Zhu , Wanxuan Lu , Hua Huang

Radio interferometers designed to probe the 21cm signal from Cosmic Dawn and the Epoch of Reionisation must contend with systematic effects that make it difficult to achieve sufficient dynamic range to separate the 21cm signal from…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-24 Fraser Kennedy , Philip Bull , Michael Wilensky , Jacob Burba , Samir Choudhuri

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