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Our present understanding of the extragalactic source counts and background radiation at infrared and sub-mm wavelengths is reviewed. Available count data are used to constrain evolutionary models of galaxies and Active Nuclei. The CIRB, on…

The cosmic microwave background temperature is a cornerstone astrophysical observable. Its present value is tightly constrained, but its redshift dependence, which can now be determined until redshift $z\sim6.34$, is also an important probe…

宇宙学与河外天体物理 · 物理学 2022-11-23 L. Gelo , C. J. A. P. Martins , N. Quevedo , A. M. M. Vieira

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the first stars, which may have formed before…

天体物理学 · 物理学 2012-08-27 H. E. S. S. Collaboration , : , F. Aharonian

We provide our estimates of the intensity of the gamma-ray emission with an energy near 0.1 TeV generated in inrergalactic space in the interactions of cosmic rays with background emissions. We assume that the cosmic ray sources are…

高能天体物理现象 · 物理学 2017-08-30 A. V. Uryson

We estimate the level of confusion to Cosmic Microwave Background anisotropy measurements caused by extragalactic infrared sources. CMB anisotropy observations at high resolution and high frequencies are especially sensitive to this…

天体物理学 · 物理学 2009-10-28 Eric Gawiser , George F. Smoot

The Cosmic Microwave Background radiation is a fundamental prediction of Hot Big Bang cosmology. The temperature of its black-body spectrum has been measured at the present time, $T_{\rm CMBR,0}$ = 2.726$\pm$ 0.010 K, and is predicted to…

天体物理学 · 物理学 2016-03-23 R. Srianand , Patrick Petitjean , Cedric Ledoux

Current limits on the intensity of the extragalactic infrared background are consistent with the expected contribution from evolving galaxies. Depending on the behaviour of the star formation rate and of the initial mass function, we can…

天体物理学 · 物理学 2009-10-22 G. De Zotti , A. Franceschini , P. Mazzei , L. Toffolatti , L. Danese

Neutron stars that show X-ray and $\gamma$-ray pulsed emission must, somewhere in the magnetosphere, generate electron-positron pairs. Such pairs are also required for radio emission, but then why do a number of these sources appear radio…

高能天体物理现象 · 物理学 2023-04-19 Inés Pastor-Marazuela , Samayra M. Straal , Joeri van Leeuwen , Vlad I. Kondratiev

Understanding diffuse Galactic radio emission is interesting both in its own right and for minimizing foreground contamination of cosmological measurements. Cosmic Microwave Background experiments have focused on frequencies > 10 GHz,…

Extended, steep-spectrum radio synchrotron sources are pre-dominantly found in massive galaxy clusters as opposed to groups. LOFAR Two-Metre Sky Survey images have revealed a diffuse, ultra-steep spectrum radio source in the low-mass…

We present an alternative estimate of the unresolved point source contribution to the WMAP temperature power spectrum based on current knowledge of sources from radio surveys in the 1.4-90 GHz range. We implement a stochastic extrapolation…

宇宙学与河外天体物理 · 物理学 2015-05-18 Loris P. L. Colombo , Elena Pierpaoli

The vast majority of extragalactic compact continuum radio sources are associated with star formation or jets from (super)massive black holes and, as such, are more likely to be found in association with starburst galaxies or early-type…

高能天体物理现象 · 物理学 2023-12-20 D. Vohl , H. K. Vedantham , J. W. T. Hessels , C. G. Bassa , D. O. Cook , D. L. Kaplan , T. W. Shimwell , C. Zhang

We present a revised measurement of the extra-galactic background light (EBL) at radio frequencies based on a near complete compendium of radio source counts. We present the radio-EBL at 150 MHz, 325 MHz, 610 MHz, 1.4 GHz, 3 GHz, 5 GHz, and…

The radio sky at frequencies below $\sim10$ MHz is still largely unknown, this remains the last unexplored part of the electromagnetic spectrum in astronomy. The upcoming space experiments aiming at such low frequencies (ultra-long…

星系天体物理 · 物理学 2021-06-30 Yanping Cong , Bin Yue , Yidong Xu , Qizhi Huang , Shifan Zuo , Xuelei Chen

We report on the detection of a feature with negative radio flux in a sensitive, low resolution observation with the VLA. This morphologically peculiar feature is approximately 25" 65" in size with a peak central amplitude of about -0.25 mK…

天体物理学 · 物理学 2015-06-24 E. A. Richards , E. B. Fomalont , K. I. Kellermann , R. B. Partridge , R. A. Windhorst

The radio emission of a galaxy consists of thermal bremsstrahlung, synchrotron emission from discrete supernova remnants, and diffuse synchrotron emission from cosmic ray electrons spread over the galactic disk and halo. Each of these…

天体物理学 · 物理学 2007-05-23 U. Lisenfeld , H. J. Voelk

Infrared surveys provide essential insights on galaxy evolution. If near-IR studies suggest mild evolution of stellar populations with cosmic time, indications of a substantial evolution have been seen in the far-IR, although the available…

天体物理学 · 物理学 2016-08-30 G. DeZotti , A. Franceschini , P. Mazzei , L. Granato , L. Danese

A detailed knowledge of the Galactic radio continuum is of high interest for studies of the dynamics and structure of the Galaxy as well as for the problem of foreground removal in Cosmic Microwave Background measurements. In this work we…

天体物理学 · 物理学 2011-05-23 P. Platania , C. Burigana , D. Maino , E. Caserini , M. Bersanelli , B. Cappellini , A. Mennella

We present radio observations of the Moon between $35$ and $80$ MHz to demonstrate a novel technique of interferometrically measuring large-scale diffuse emission extending far beyond the primary beam (global signal) for the first time. In…

Aims: We study the Galactic large-scale synchrotron emission by generating a reliable all-sky spectral index map and temperature map at 45 MHz. Methods: We use our observations, the published all-sky map at 408 MHz, and a bibliographical…

星系天体物理 · 物理学 2010-12-10 Andres E. Guzmán , Jorge May , Hector Alvarez , Koitiro Maeda