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We cross-correlate the Saskatoon Q-Band data with different spatial template maps to quantify possible foreground contamination. We detect a correlation with the Diffuse Infrared Background Experiment (DIRBE) 100 microm map, which we…

We report the test results of several independent foreground-cleaning pipelines used in the Ali CMB Polarization Telescope experiment (AliCPT-1), a high-altitude CMB imager in the Northern hemisphere with thousands of detectors dedicated to…

The Medium Energy X-ray Telescope (ME) is one of the main payloads of the Hard X-ray Modulation Telescope (dubbed as Insight-HXMT). The background of Insight-HXMT/ME is mainly caused by the environmental charged particles and the background…

Image quality in mosaicked observations from interferometric radio telescopes is strongly dependent on the accuracy with which the antenna primary beam is calibrated. The next generation of radio telescope arrays such as the Allen Telescope…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Charles L. H. Hull , Geoffrey C. Bower , Steve Croft , Peter K. G. Williams , Casey Law , David Whysong

The most promising avenue for detecting primordial gravitational waves from cosmic inflation is through measurements of degree-scale CMB $B$-mode polarisation. This approach must face the challenge posed by gravitational lensing of the CMB,…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-20 Antón Baleato Lizancos , Anthony Challinor , Blake D. Sherwin , Toshiya Namikawa

Measurement of the power spectrum of high redshift 21 cm emission from neutral hydrogen probes the formation of the first luminous objects and the ionization of intergalactic medium by the first stars. However, the 21 cm signal at these…

Instrumentation and Methods for Astrophysics · Physics 2025-08-13 Katherine Elder , Daniel C. Jacobs , Maria Kovaleva

Foreground removal remains an ongoing challenge in radio cosmology, and increasingly sensitive experiments necessitate more robust analysis techniques. In this work, we model simulated data from a single-dish intensity mapping experiment,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-30 Geoff G. Murphy , Philip Bull , Mario G. Santos , Zheng Zhang , Steven Cunnington

We present a simulation experiment of a pipeline based on machine learning algorithms for neutral hydrogen (HI) intensity mapping (IM) surveys with different telescopes. The simulation is conducted on HI signals, foreground emission,…

Instrumentation and Methods for Astrophysics · Physics 2022-09-14 Lin-Cheng Li , Yuan-Gen Wang

A new method for removing point radio sources and other non-Gaussian noise is proposed as a means of improving the accuracy of estimates of the angular power spectrum of the cosmic microwave background (CMB). The main idea of the method is…

Astrophysics · Physics 2009-11-13 Anisa T. Bajkova

Cosmological parameter estimation in the post-reionisation era via neutral hydrogen radio emission ($\text{\hi}$), is among the key science goals of the forthcoming SKA Observatory (SKAO). This paper explores detection capability for baryon…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-18 Andrea Rubiola , Steven Cunnington , Stefano Camera

The cross-correlation of a foreground density field with two different background convergence fields can be used to measure cosmographic distance ratios and constrain dark energy parameters. We investigate the possibility of performing such…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-11 Alkistis Pourtsidou , David Bacon , Robert Crittenden

Intensity mapping -- the large-scale mapping of selected spectral lines without resolving individual sources -- is quickly emerging as an efficient way to conduct large cosmological surveys. Multiple surveys covering a variety of lines…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Hannah Fronenberg , Adrian Liu

The effects on CMB measurements of foreground contamination due to synchrotron radiation, free-free emission and discrete sources are considered. Estimates of the level and power spectrum of the Galactic fluctuations are made using low…

Astrophysics · Physics 2007-05-23 A. N. Lasenby

We derive a fast way for measuring primordial non-Gaussianity in a nearly full-sky map of the cosmic microwave background. We find a cubic combination of sky maps combining bispectrum configurations to capture a quadratic term in primordial…

Astrophysics · Physics 2009-11-07 Eiichiro Komatsu , David N. Spergel , Benjamin D. Wandelt

Diffuse contamination from Galactic foreground emission is one of the main concerns for reconstruction of the cosmic microwave background (CMB) lensing potential for next-generation CMB polarisation experiments. Using realistic simulations,…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Kishan Deka , Pawel Bielewicz

The redshifted 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR). However, its detection requires a thorough understanding and control of the systematic errors. We study two systematic biases observed in…

We perform multi-scale non-Gaussianity detection and localization to the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data in both wavelet and real spaces. Such an analysis is facilitated by spherical wavelet transform and inverse…

Astrophysics · Physics 2009-11-11 Xin Liu , Shuang Nan Zhang

Extragalactic foregrounds in temperature maps of the Cosmic Microwave Background (CMB) severely limit the ability of standard estimators to reconstruct the weak lensing potential. These foregrounds are not fully removable by multi-frequency…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-03 Noah Sailer , Emmanuel Schaan , Simone Ferraro

One of the greatest impediments to extracting useful information from high luminosity hadron-collider data is radiation from secondary collisions (i.e. pileup) which can overlap with that of the primary interaction. In this paper we…

High Energy Physics - Phenomenology · Physics 2014-10-03 David Krohn , Matthew Low , Matthew D. Schwartz , Lian-Tao Wang

Neutral hydrogen (H$_{\rm I}$) intensity mapping is capable of measuring redshift evolution of H$_{\rm I}$ density parameter $\Omega_{\rm H_{\rm I}}$, which is an important parameter to understand structure formation in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-28 Shoichiro Tanaka , Shintaro Yoshiura , Kenji Kubota , Keitaro Takahashi , Atsushi J. Nishizawa , Naoshi Sugiyama