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Related papers: Low multipole mapmaking for global 21-cm experimen…

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CMB mapmaking relies on a data model to solve for the sky map, and this process is vulnerable to bias if the data model cannot capture the full behavior of the signal. We demonstrate that this bias is not just limited to small-scale effects…

Instrumentation and Methods for Astrophysics · Physics 2024-08-30 Sigurd Naess , Thibaut Louis

We reconsider the pixel-based, "template" polarized foreground removal method within the context of a next-generation, low-noise, low-resolution (0.5 degree FWHM) space-borne experiment measuring the cosmological B-mode polarization signal…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Nobuhiko Katayama , Eiichiro Komatsu

Broadband time-ordered data obtained from telescopes with a wavelength-dependent, asymmetric beam pattern can be used to extract maps at multiple wavelengths from a single scan. This technique is especially useful when collecting data on…

Instrumentation and Methods for Astrophysics · Physics 2023-06-06 Brianna Cantrall , Solomon Quinn , Emory F. Bunn

We apply state-of-the art data analysis methods to a number of fictitious CMB mapping experiments, including 1/f noise, distilling the cosmological information from time-ordered data to maps to power spectrum estimates, and find that in all…

Astrophysics · Physics 2008-11-26 Max Tegmark

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

The Cosmological Principle states that the universe is statistically isotropic and homogeneous on large length scales, typically $\gtrsim 70$Mpc. A detection of significant deviation would help us falsify the simplest models of inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Bhuwan Joshi , Rahul Kothari

We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Samir Choudhuri , Somnath Bharadwaj , Abhik Ghosh , SK. Saiyad Ali

The future 21 cm intensity mapping observations constitute a promising way to trace the matter distribution of the Universe and probe cosmology. Here we assess its capability for cosmological constraints using as a case study the BINGO…

The presence of astrophysical emissions between the last scattering surface and our vantage point requires us to apply a foreground mask on CMB sky map, leading to large cut around the Galactic equator and numerous holes. Since many CMB…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-17 Jaiseung Kim , Pavel Naselsky , Nazzareno Mandolesi

Most analysis of Cosmic Microwave Background spherical harmonic coefficients a_lm has focused on estimating the power spectrum C_l=<|a_lm|^2> rather than the coefficients themselves. We present a minimum-variance method for measuring a_lm…

Astrophysics · Physics 2009-10-07 Angelica de Oliveira-Costa , Max Tegmark

Global (i.e. sky-averaged) $21$~cm signal experiments can measure the evolution of the universe from the Cosmic Dawn to the Epoch of Reionization. These measurements are challenged by the presence of bright foreground emission that can be…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Marta Spinelli , Gianni Bernardi , Mario G. Santos

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

Global 21cm experiments aim to measure the sky averaged HI absorption signal from cosmic dawn and the epoch of reionisation. However, antenna chromaticity coupling to bright foregrounds can introduce distortions into the observational data…

Instrumentation and Methods for Astrophysics · Physics 2021-11-12 Dominic Anstey , John Cumner , Eloy de Lera Acedo , Will Handley

A measurement of the 21-cm global signal would be a revealing probe of the Dark Ages, the era of first star formation, and the Epoch of Reionization. It has remained elusive owing to bright galactic and extra-galactic foreground…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-20 Yordan D. Ignatov , Jonathan R. Pritchard , Yuqing Wu

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

The low surface brightness (LSB) regime ($\mu_{g} \gtrsim 26$ mag arcsec$^{-2}$) comprises a vast, mostly unexplored discovery space, from dwarf galaxies to the diffuse interstellar medium. Accessing this regime requires precisely removing…

Astrophysics of Galaxies · Physics 2024-01-24 A. E. Watkins , S. Kaviraj , C. C. Collins , J. H. Knapen , L. S. Kelvin , P. -A. Duc , J. Román , J. C. Mihos

In this paper we continue to develop the m-mode formalism, a technique for efficient and optimal analysis of wide-field transit radio telescopes, targeted at 21 cm cosmology. We extend this formalism to give an accurate treatment of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 J. Richard Shaw , Kris Sigurdson , Michael Sitwell , Albert Stebbins , Ue-Li Pen

We study the morphology of convergence maps by perturbatively reconstructing their Minkowski Functionals (MFs). We present a systematics study using a set of three generalised skew-spectra as a function of source redshift and smoothing…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-01 D. Munshi , T. Namikawa , J. D. McEwen , T. D. Kitching , F. R. Bouchet

Precise measurement of the foreground synchrotron emission, which contaminates the faint polarized cosmic microwave background radiation (CMB), is a major challenge for the next-generation of CMB experiments. To address this, dedicated…