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We study Minkowski Functionals as probes of primordial non-Gaussianity in the Cosmic Microwave Background, specifically for the estimate of the primordial `local' bi-spectrum parameter f_NL, with instrumental parameters which should be…

宇宙学与河外天体物理 · 物理学 2015-06-11 Anne Ducout , François Bouchet , Stéphane Colombi , Dmitri Pogosyan , Simon Prunet

We discuss the ground-breaking science that will be possible with a wide area survey, using the MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of MeerKAT make it a great fit for…

Reconstructed maps of the lensing convergence of the cosmic microwave background (CMB) will play a major role in precision cosmology in coming years. CMB lensing maps will enable calibration of the masses of high-redshift galaxy clusters…

宇宙学与河外天体物理 · 物理学 2018-08-01 Mathew S. Madhavacheril , J. Colin Hill

We present a differentiable, end-to-end Bayesian forward modeling framework for line intensity mapping cosmology experiments, with a specific focus on low-frequency radio telescopes targeting the redshifted 21 cm line from neutral hydrogen…

宇宙学与河外天体物理 · 物理学 2025-07-15 Nicholas Kern

We present new constraints on the local-type primordial non-Gaussianity parameter, $f_\mathrm{NL}^\mathrm{local}$, through analysis of the scale-dependent bias effect on the cosmic infrared background (CIB). To avoid biases from galactic…

宇宙学与河外天体物理 · 物理学 2026-05-06 Joseph Thornton , Fiona McCarthy , Carmen Embil Villagra , Blake D. Sherwin

In this paper we present a new method to estimate a foreground cleaned Cosmic Microwave Background (CMB) map at a resolution of $1^\circ$ by minimizing the non-Gaussian properties of the cleaned map which arise dominantly due to diffuse…

宇宙学与河外天体物理 · 物理学 2015-05-28 Rajib Saha

Constraints on primordial non-Gaussianity (PNG) will shed light on the origin of primordial fluctuations and the physics of the early universe. The intensity mapping technique is a promising probe of structure formation on large scales; at…

宇宙学与河外天体物理 · 物理学 2019-02-27 Azadeh Moradinezhad Dizgah , Garrett K. Keating

We forecast ability of dedicated 21 cm intensity mapping experiments to constraint primordial non-Gaussianity using power spectrum and bispectrum. We model the signal including the non-linear biasing expansion using a generalized halo model…

宇宙学与河外天体物理 · 物理学 2020-11-30 Dionysios Karagiannis , Anže Slosar , Michele Liguori

Radio Frequency Interference (RFI) is emitted from various sources, terrestrial or orbital, and create a nuisance for ground-based 21cm experiments. In particular, single-dish 21cm intensity mapping experiments will be highly susceptible to…

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…

宇宙学与河外天体物理 · 物理学 2023-07-24 Fraser Kennedy , Philip Bull , Michael Wilensky , Jacob Burba , Samir Choudhuri

Measuring one-point statistics in redshifted 21 cm intensity maps offers an opportunity to explore non-Gaussian features of the early universe. We assess the impact of instrumental effects on measurements made with the Hydrogen Epoch of…

One of the main challenges facing upcoming CMB experiments will be to distinguish the cosmological signal from foreground contamination. We present a comprehensive treatment of this problem and study how foregrounds degrade the accuracy…

天体物理学 · 物理学 2009-10-07 Max Tegmark , Daniel J. Eisenstein , Wayne Hu , Angelica de Oliveira-Costa

The 21 cm intensity mapping provides a promising probe of the large-scale structure. Astrophysical foregrounds, as the main source of contamination to the cosmological 21 cm signal, persist in a wedge-like region of Fourier space due to the…

宇宙学与河外天体物理 · 物理学 2026-02-04 Kaifeng Yu , Xin Wang

21cm intensity mapping experiments aim to observe the diffuse neutral hydrogen (HI) distribution on large scales which traces the Cosmic structure. The Square Kilometre Array (SKA) will have the capacity to measure the 21cm signal over a…

Line intensity mapping using atomic hydrogen (HI) has the potential to efficiently map large volumes of the universe if the signal can be successfully separated from overwhelmingly bright radio foreground emission. This motivates…

Observational cosmology is entering an era in which high precision will be required in both measurement and data analysis. Accuracy, however, can only be achieved with a thorough understanding of potential sources of contamination from…

宇宙学与河外天体物理 · 物理学 2015-11-19 Assaf Ben-David , Sebastian von Hausegger , Andrew D. Jackson

Extracting the neutral hydrogen (HI) signal is a great challenge for cosmological 21cm experiments, both the astrophysical foregrounds and the receiver noise are typically several orders of magnitude greater than the 21cm signal. However,…

宇宙学与河外天体物理 · 物理学 2019-06-14 Qizhi Huang , Fengquan Wu , Reza Ansari , Xuelei Chen

After a decade of design and construction, South Africa's SKA-MID precursor MeerKAT has begun its science operations. To make full use of the widefield capability of the array, it is imperative that we have an accurate model of the primary…

Radio astronomical imaging using aperture synthesis telescopes requires deconvolution of the point spread function as well as calibration of the instrumental characteristics (primary beam) and foreground (ionospheric/atmospheric) effects.…

天体物理仪器与方法 · 物理学 2011-11-24 Juan M. Uson , William D. Cotton

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…

天体物理学 · 物理学 2015-06-24 Max Tegmark , George Efstathiou