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相关论文: A Clustered Extragalactic Foreground Model for the…

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We discuss the main uncertainties affecting estimates of small scale fluctuations due to extragalactic sources in the Planck Surveyor frequency bands. Conservative estimates allow us to confidently conclude that, in the frequency range…

天体物理学 · 物理学 2007-05-23 G. De Zotti , L. Toffolatti

Twenty-one-centimetre signals from the Epoch of Reionization (EoR) are expected to be detected in the low-frequency radio window by the next-generation interferometers, particularly the Square Kilometre Array (SKA). However, precision data…

We present new observations with the Precision Array for Probing the Epoch of Reionization (PAPER) with the aim of measuring the properties of foreground emission for 21cm Epoch of Reionization experiments at 150 MHz. We focus on the…

The detection of the redshifted cosmological $21$~cm line signal requires the removal of the Galactic and extragalactic foreground emission, which is orders of magnitude brighter anywhere in the sky. Foreground cleaning methods currently…

宇宙学与河外天体物理 · 物理学 2018-06-13 M. Spinelli , G. Bernardi , M. G. Santos

We study the effect of extragalactic point sources on satellite observations of the cosmic microwave background (CMB). In order to separate the contributions due to different foreground components, a maximum-entropy method is applied to…

天体物理学 · 物理学 2009-10-31 M. P. Hobson , R. B. Barreiro , L. Toffolatti , A. N. Lasenby , J. L. Sanz , A. W. Jones , F. R. Bouchet

The ultra-high contrast capability required to form images of other solar systems is arguably the highest-profile challenge in astronomy today. The current high-contrast imaging efforts all require background subtraction to separate the…

天体物理仪器与方法 · 物理学 2015-07-29 Richard A. Frazin

It has recently become apparent that the background level of diffuse radio emission on the sky is significantly higher than the level that can result from known extragalactic radio source classes or our Galaxy given our current…

宇宙学与河外天体物理 · 物理学 2019-12-02 J. Singal

Tomography of redshifted 21 cm transition from neutral Hydrogen using Fourier synthesis telescopes is a promising tool to study the Epoch of Reionization (EoR). Limiting the confusion from Galactic and Extragalactic foregrounds is critical…

天体物理仪器与方法 · 物理学 2015-05-28 Harish Vedantham , N. Udaya Shankar , Ravi Subrahmanyan

Characterizing the sub-mm Galactic emission has become increasingly critical especially in identifying and removing its polarized contribution from the one emitted by the Cosmic Microwave Background (CMB). In this work, we present a…

The combination of galaxy-galaxy lensing (GGL) with galaxy clustering is one of the most promising routes to determining the amplitude of matter clustering at low redshifts. We show that extending clustering+GGL analyses from the linear…

Despite the influx of unprecedented-quality data from the Fermi Gamma-Ray Space Telescope that have been collected over nine years of operation, the contribution of normal star-forming galaxies to the extragalactic gamma-ray background…

高能天体物理现象 · 物理学 2018-12-19 I. Komis , V. Pavlidou , A. Zezas

We present an extensive analysis on the determination of the isotropic radio background. We consider six different radio maps, ranging from 22 MHz to 2.3 GHz and covering a large fraction of the sky. The large scale emission is modeled as a…

宇宙学与河外天体物理 · 物理学 2015-06-18 Nicolao Fornengo , Roberto A. Lineros , Marco Regis , Marco Taoso

We explore the potential of a future, ultra-high energy cosmic ray (UHECR) experiment, that is able to overcome the limitation of low statistics, to detect anisotropy in the arrival directions of UHECRs. We concentrate on the lower energy…

高能天体物理现象 · 物理学 2015-01-28 Foteini Oikonomou , Kumiko Kotera , Filipe B. Abdalla

We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um & ~1mJy at 6.7um. We separate the stellar contribution from the…

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…

宇宙学与河外天体物理 · 物理学 2019-05-23 Ben Thorne , Jo Dunkley , David Alonso , Maximilian H. Abitbol , Josquin Errard , J. Colin Hill , Brian Keating , Grant Teply , Edward J. Wollack

We study the nonlinear $E$-mode clustering in Lagrangian space by using large scale structure $N$-body simulations and use the displacement field information in Lagrangian space to recover the primordial linear density field. We find that,…

宇宙学与河外天体物理 · 物理学 2017-02-28 Hao-Ran Yu , Ue-Li Pen , Hong-Ming Zhu

A probabilistic technique for the joint estimation of background and sources with the aim of detecting faint and extended celestial objects is described. Bayesian probability theory is applied to gain insight into the coexistence of…

天体物理仪器与方法 · 物理学 2015-05-13 F. Guglielmetti , R. Fischer , V. Dose

Polarized Galactic synchrotron emission is an undesirable foreground for cosmic microwave background (CMB) experiments observing at frequencies $< 150$ GHz. We perform a combined analysis of observational data at 1.4, 2.3, 23, 30 and 33 GHz…

宇宙学与河外天体物理 · 物理学 2022-09-07 Janet L. Weiland , Graeme E. Addison , Charles L. Bennett , Mark Halpern , Gary Hinshaw

Astrophysical flares are one of the possible prominent source classes of ultra-high-energy (UHE, $E > 10^{17}$ eV) cosmic rays, which can be detected by recording clusters of extensive air showers in arrays of detectors. The search for…

高能天体物理现象 · 物理学 2025-10-01 Jaroslaw Stasielak , Chaitanya Priyadarshi , Dariusz Góra , Nataliia Borodai , Marcus Niechciol , Jan Pękala

We show that Compton scattering by electrons of the hot intergalactic gas in galaxy clusters should lead to peculiar distortions of the cosmic background X-ray and soft gamma-ray radiation - an increase in its brightness at E<60-100 keV and…

高能天体物理现象 · 物理学 2020-04-23 S. A. Grebenev , R. A. Sunyaev