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Future high redshift 21-cm experiments will suffer from a high degree of contamination, due both to astrophysical foregrounds and to non-astrophysical and instrumental effects. In order to reliably extract the cosmological signal from the…

Detecting cosmological signals from the Epoch of Reionization (EoR) requires high-precision calibration to isolate the cosmological signals from foreground emission. In radio interferometery, perturbed primary beams of antenna elements can…

We present the detection and characterization of fluctuations in linearly polarized emission from the atmosphere above the South Pole. These measurements make use of data from the SPT-3G receiver on the South Pole Telescope in three…

We perform a Fisher analysis to estimate the expected constraints on the Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature, the ionizing efficiency and the mean free path of ionizing photons) taking into account…

宇宙学与河外天体物理 · 物理学 2017-04-04 Hayato Shimabukuro , Shintaro Yoshiura , Keitaro Takahashi , Shuichiro Yokoyama , Kiyotomo Ichiki

Detecting redshifted 21cm emission from neutral hydrogen in the early Universe promises to give direct constraints on the epoch of reionization (EoR). It will, though, be very challenging to extract the cosmological signal (CS) from…

Observations of the EoR with the 21-cm hyperfine emission of neutral hydrogen (HI) promise to open an entirely new window onto the formation of the first stars, galaxies and accreting black holes. In order to characterize the weak 21-cm…

宇宙学与河外天体物理 · 物理学 2015-08-06 Abhik Ghosh , L. V. E. Koopmans , Emma Chapman , Vibor Jelic

Linearly polarized emission is described, in general, in terms of the Stokes parameters $Q$ and $U$, from which the polarization intensity and polarization angle can be determined. Although the polarization intensity and polarization angle…

星系天体物理 · 物理学 2018-01-31 C. A. Herron , B. M. Gaensler , G. F. Lewis , N. M. McClure-Griffiths

A crucial problem for partial sky analysis of CMB polarization is the $E$-$B$ leakage problem. Such leakage arises from the presence of `ambiguous' modes that satisfy properties of both $E$ and $B$ modes. Solving this problem is critical…

宇宙学与河外天体物理 · 物理学 2021-03-03 Shamik Ghosh , Jacques Delabrouille , Wen Zhao , Larissa Santos

The turbulent ionosphere causes phase shifts to incoming radio waves on a broad range of temporal and spatial scales. When an interferometer is not sufficiently calibrated for the direction-dependent ionospheric effects, the time-varying…

With the forthcoming release of high precision polarization measurements, such as from the Planck satellite, the metrology of polarization needs to improve. In particular, it is crucial to take into account full knowledge of the noise…

天体物理仪器与方法 · 物理学 2015-02-11 L. Montier , S. Plaszczynski , F. Levrier , M. Tristram , D. Alina , I. Ristorcelli , J. -P. Bernard

The Epoch of Reionization (EoR), when the first luminous sources ionised the intergalactic medium, represents a new frontier in cosmology. The Square Kilometre Array Observatory (SKAO) will offer unprecedented insights into this era through…

Polarimetric studies of pulsar radio emission traditionally concentrate on how the Stokes vector (I, Q, U, V) varies with pulse longitude, with special emphasis on the position angle (PA) swing of the linearly polarized component. The…

太阳与恒星天体物理 · 物理学 2011-03-08 C. T. Y. Chung , A. Melatos

We present LOFAR measurements of radio emission from extensive air showers. We find that this emission is strongly polarized, with a median degree of polarization of nearly $99\%$, and that the angle between the polarization direction of…

Accurate measurement of polarization in spectral lines is important for the reliable inference of magnetic fields on the Sun. For ground based observations, polarimetric precision is severely limited by the presence of Earth's atmosphere.…

仪器与探测器 · 物理学 2012-11-05 K. Nagaraju , Alex Feller

21 cm Epoch of Reionization observations promise to transform our understanding of galaxy formation, but these observations are impossible without unprecedented levels of instrument calibration. We present end-to-end simulations of a full…

天体物理仪器与方法 · 物理学 2016-06-09 N. Barry , B. Hazelton , I. Sullivan , M. F. Morales , J. C. Pober

Redshifted 21cm-line signal from neutral hydrogens in the intergalactic medium (IGM) gives a direct probe of the epoch of reionization (EoR). In this paper, we investigate the potential of the variance and skewness of the probability…

宇宙学与河外天体物理 · 物理学 2018-08-31 Kenji Kubota , Shintaro Yoshiura , Hayato Shimabukuro , Keitaro Takahashi

We present deep polarimetric observations at 1420 MHz of the European Large Area ISO Survey North 1 region (ELAIS N1) as part of the Dominion Radio Astrophysical Observatory Planck Deep Fields project. By combining closely spaced aperture…

Interferometry of the cosmic 21-cm signal is set to revolutionize our understanding of the Epoch of Reionization (EoR), eventually providing 3D maps of the early Universe. Initial detections however will be low signal-to-noise, limited by…

宇宙学与河外天体物理 · 物理学 2016-04-20 Emanuele Sobacchi , Andrei Mesinger , Bradley Greig

By measuring photoelectron tracks, the gas pixel detectors of the Imaging X-ray Polarimetry Explorer satellite provide estimates of the photon detection location and its electric vector position angle (EVPA). However, imperfections in…

天体物理仪器与方法 · 物理学 2024-09-24 Jack T. Dinsmore , Roger W. Romani

The advent of a new generation of low frequency interferometers has opened a direct window into the Epoch of Reionisation (EoR). However, key to a detection of the faint 21-cm signal, and reaching the sensitivity limits of these arrays, is…

天体物理仪器与方法 · 物理学 2018-12-05 Ronniy C. Joseph , Cathryn M. Trott , Randall B. Wayth