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Cross-correlation between the redshifted 21 cm signal and Lyman-{\alpha} emitters (LAEs) is powerful tool to probe the Epoch of Reionization (EoR). Although the cross-power spectrum (PS) has an advantage of not correlating with foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-25 S. Yoshiura , J. L. B. Line , K. Kubota , K. Hasegawa , K. Takahashi

The redshifted cosmic 21 cm line signal of neutral hydrogen provides the possibility to constrain the matter power spectrum. Cross correlating temperature maps at different frequencies (corresponding to different redshifts along the line of…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-20 Kerstin E. Kunze

A proposed method for dealing with foreground emission in upcoming 21-cm observations from the epoch of reionization is to limit observations to an uncontaminated window in Fourier space. Foreground emission can be avoided in this way,…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-23 Hannes Jensen , Suman Majumdar , Garrelt Mellema , Adam Lidz , Ilian T. Iliev , Keri L. Dixon

Isotropy-violation statistics can highlight polarized galactic foregrounds that contaminate primordial $B$-modes in the Cosmic Microwave Background (CMB). We propose a particular isotropy-violation test and apply it to polarized Planck 353…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-23 Aditya Rotti , Kevin Huffenberger

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

The observation of the polarised emission from the Cosmic Microwave Background (CMB) from future ground-based and satellite-borne experiments holds the promise of indirectly detecting the elusive signal from primordial tensor fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-22 Susanna Azzoni , David Alonso , Maximilian H. Abitbol , Josquin Errard , Nicoletta Krachmalnicoff

Upcoming observations from the Simons Observatory have been projected to constrain the tensor-to-scalar ratio, $r$, at the level of $\sigma(r)=$0.003. Here we describe one of the forecasting algorithms for the Simons Observatory in more…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-23 Ben Thorne , Jo Dunkley , David Alonso , Maximilian H. Abitbol , Josquin Errard , J. Colin Hill , Brian Keating , Grant Teply , Edward J. Wollack

Contamination from instrumental effects interacting with bright astrophysical sources is the primary impediment to measuring Epoch of Reionization and BAO 21 cm power spectra---an effect called mode-mixing. In this paper we identify four…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Miguel F. Morales , Bryna Hazelton , Ian Sullivan , Adam Beardsley

Present day cosmic microwave background (CMB) studies require more accurate removal of Galactic foreground emission. In this paper, we consider a way of filtering out the diffuse Galactic fluctuations on the basis of their statistical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Jungyeon Cho , A. Lazarian

We report a measurement of anisotropy in the cosmic microwave background radiation (CMBR) on 7-22 arcminute scales. Observations of 36 fields near the North Celestial Pole (NCP) were made at 31.7 and 14.5 GHz, using the 5.5-meter and…

Astrophysics · Physics 2007-05-23 E. M. Leitch , A. C. S. Readhead , T. J. Pearson , S. T. Myers , S. Gulkis , C. R. Lawrence

After reionization, emission in the 21 cm hyperfine transition provides a direct probe of neutral hydrogen distributed in galaxies. Different from galaxy redshift surveys, observation of baryon acoustic oscillations in the cumulative 21 cm…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Xiao-Chun Mao

CMB foregrounds consist of all radiation between the surface of last scattering and the detectors, which can interfere with the cosmological interpretation of CMB data. Fortunately, in temperature (intensity), even though the foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-14 Clive Dickinson

The 21 cm brightness temperature during the Epoch of Reionisation is widely modelled using semi-numeric simulations, used for their computational speed and flexibility in testing astrophysical and cosmological parameters. However, it is…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jennifer Feron , Emma Chapman

Detecting a stochastic gravitational wave background requires that we first understand and model any astrophysical foregrounds. In the millihertz frequency band, the predominate foreground signal will be from unresolved white dwarf binaries…

General Relativity and Quantum Cosmology · Physics 2014-01-23 Matthew R. Adams , Neil J. Cornish

HI intensity mapping is an emerging tool to probe dark energy. Observations of the redshifted HI signal will be contaminated by instrumental noise, atmospheric and Galactic foregrounds. The latter is expected to be four orders of magnitude…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-28 M. -A. Bigot-Sazy , C. Dickinson , R. A. Battye , I. W. A. Browne , Y. -Z. Ma , B. Maffei , F. Noviello , M. Remazeilles , P. N. Wilkinson

Power spectrum estimators are an important tool in efforts to detect the 21 cm brightness temperature fluctuations from neutral hydrogen at early times. An initial detection will likely be statistical in nature, meaning that it will not be…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-24 Jacob Burba , Philip Bull , Michael J. Wilensky , Fraser Kennedy , Hugh Garsden , Katrine A. Glasscock

Intensity mapping is a promising technique for surveying the large scale structure of our Universe from $z=0$ to $z \sim 150$, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Adrian Liu , Yunfan Zhang , Aaron R. Parsons

Several ongoing and upcoming radio telescopes aim to detect either the global 21 cm signal or the 21 cm power spectrum. The extragalactic radio background, as detected by ARCADE-2 and LWA-1, suggests a strong radio background from cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-24 Sudipta Sikder , Anastasia Fialkov , Rennan Barkana

The existence of a radio synchrotron background (RSB) excess is implied by a number of measurements, including excess emission seen by the ARCADE~2 and LWA experiments. Highly sensitive wideband radio arrays, of the kind used to measure the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-16 Zheng Zhang , Philip Bull , Katrine A. Glasscock

We summarize the relationship between the free-free emission foreground and Galactic H-alpha emission. H-alpha observations covering nearly the entire celestial sphere are described. These data provide a template to isolate and/or remove…

Astrophysics · Physics 2008-11-26 P. R. McCullough , J. E. Gaustad , W. Rosing , D. Van Buren
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