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相关论文: Low Frequency Radio Constraints on the Synchrotron…

200 篇论文

Clusters of galaxies host spectacular diffuse radio sources, extending over scales from 100 kpc to several Mpcs. These sources, with extremely faint surface brightness ($\mu$Jy/arcsec$^2$ level), are not tied to individual galaxies but…

Building the radio sky template are crucial for detecting the 21 cm emission line signal from the Epoch of Reionization (EoR), as well as for other cosmological research endeavors. Utilizing data from the LOFAR Two-meter Sky Survey (LoTSS)…

星系天体物理 · 物理学 2024-11-07 Jinyang Lin , Zhenghao Zhu , Renyi Ma , Anna Bonaldi , Huanyuan Shan

Galactic foreground emission is a limiting factor for precise cosmic microwave background (CMB) anisotropy measurements. We perform an angular power spectrum analysis (APS) of all-sky total intensity maps at 408 MHz and 1420 MHz, which are…

天体物理学 · 物理学 2009-11-13 L. La Porta , C. Burigana , W. Reich , P. Reich

We build template maps for the polarized Galactic--synchrotron emission on large angular scales (FWHM =~7$^\circ$), in the 20-90 GHz microwave range, by using WMAP data. The method, presented in a recent work, requires a synchrotron total…

天体物理学 · 物理学 2009-11-10 G. Bernardi , E. Carretti , R. Fabbri , C. Sbarra , S. Poppi , S. Cortiglioni , J. L. Jonas

We perform a detailed analysis of the synchrotron signals produced by Dark Matter annihilations and decays. We consider different set-ups for the propagation of electrons and positrons, the galactic magnetic field and Dark Matter…

高能物理 - 唯象学 · 物理学 2025-07-29 Marco Cirelli , Marco Taoso

In this paper we combine the Early Science radio continuum data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey, with optical and near-infrared data and release the cross-matched catalogues. The radio…

Most of the Universe's populations of low energy cosmic ray electrons in the energy range of 1-100 MeV still manage to elude from detection by our instruments, since their synchrotron emission is at too low frequencies. We investigate a…

天体物理学 · 物理学 2009-11-06 Torsten A. Ensslin , Rashid A. Sunyaev

We study the effects of diffuse Galactic, far-infrared extragalactic source, and radio point source emission on the cosmic microwave background (CMB) anisotropy data anticipated from the MAP experiment. We focus on the correlation function…

天体物理学 · 物理学 2011-05-10 Chan-Gyung Park , Changbom Park , Bharat Ratra

We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the wide-angle interferometer at the Dominion Radio Astrophysical Observatory at Penticton,…

天体物理学 · 物理学 2010-11-05 P. P. Kronberg , R. Kothes , C. J. Salter , P. Perillat

We present an extensive synthetic observational analysis of numerically- simulated radio galaxies designed to explore the effectiveness of conventional observational analyses at recovering physical source properties. These are the first…

天体物理学 · 物理学 2009-11-10 I. L. Tregillis , T. W. Jones , Dongsu Ryu

Context: The relation between Galactic cosmic-ray electrons, magnetic fields and synchrotron radiation. Aims: We exploit synchrotron radiation to constrain the low-energy interstellar electron spectrum, using various radio surveys and…

高能天体物理现象 · 物理学 2011-10-03 A. W. Strong , E. Orlando , T. R. Jaffe

Cosmic rays (CRs) are fundamental to the chemistry and physics of star-forming regions, influencing molecular gas ionization, mediating interactions with interstellar magnetic fields, and regulating star formation from the diffuse…

The shape of low-frequency radio continuum spectra of normal galaxies is not well understood, the key question being the role of physical processes such as thermal absorption in shaping them. In this work we take advantage of the LOFAR…

I investigate the effect of non-uniform magnetic fields in the extended structures of radio galaxies on the observed synchrotron and inverse-Compton emission. On the assumption of an isotropic field, with a given power spectrum and a…

高能天体物理现象 · 物理学 2015-06-16 M. J. Hardcastle

In this paper we present a wide-field radio survey at 300 MHz covering the sky from $-90^\circ \leq \delta_\text{J2000} \lesssim +40^\circ$ using the Murchison Widefield Array (MWA). This 300-MHz survey follows the Galactic and…

The Galactic disc is opaque to radio waves from extragalactic sources with frequencies nu less than ~3 MHz. However, radio waves with kHz, Hz, and even lower frequencies may propagate through the intergalactic medium (IGM). I argue that the…

宇宙学与河外天体物理 · 物理学 2015-05-18 Brian C. Lacki

The surface brightness produced by synchrotron radiation in Clusters of Galaxies with a radio-halo sets a degenerate constraint on the magnetic field strength, the relativistic electron density and their spatial distributions. Using the…

天体物理学 · 物理学 2009-11-13 S. Colafrancesco , P. Marchegiani , G. C. Perola

Weak gravitational lensing of the CMBR manifests as a secondary anisotropy in the temperature maps. The effect, quantified through the shear and convergence fields imprint the underlying large scale structure (LSS), geometry and evolution…

宇宙学与河外天体物理 · 物理学 2010-03-19 Tapomoy Guha Sarkar

We present a new analysis of the widely used relation between cavity power and radio luminosity in clusters of galaxies with evidence for strong AGN feedback. We study the correlation at low radio frequencies using two new surveys - the…