Related papers: The Radio Background Below 100 MHz
The efficiency of radio emission is an important unknown parameter of early galaxies at cosmic dawn, as models with high efficiency have been shown to modify the cosmological 21-cm signal substantially, deepening the absorption trough and…
Apart from its anomalously large depth, the cosmological 21-cm absorption signal measured by the EDGES collaboration also has a shape that is distinctly different from theoretical predictions. Models with non-traditional components such as…
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,…
Spinning dust grains in front of the bright Galactic synchrotron background can produce a weak absorption signal that could affect measurements of high redshift 21 cm absorption. At frequencies near 80 MHz where the EDGES experiment has…
The Experiment to Detect the Global Epoch of Reionisation Signature (EDGES) collaboration has recently reported an important result related to the absorption signal in the Cosmic Microwave Background radiation spectrum. This signal…
New low frequency radio telescopes currently being built open up the possibility of observing the 21-cm radiation before the Epoch of Reionization in the future, in particular at redshifts 200 > z > 30, also known as the dark ages. At these…
The redshifted 21 cm brightness distribution from neutral hydrogen is a promising probe into the cosmic dark ages, cosmic dawn, and re-ionization. LOFAR's Low Band Antennas (LBA) may be used in the frequency range 45 MHz to 85 MHz (30>z>16)…
A recent observation by the EDGES collaboration shows a strong absorption signal in the global 21-cm spectrum from around a redshift of $z = 17$. This absorption is stronger than the maximum prediction by existing models and indicates that…
The dark ages 21-cm signal is a promising probe of the currently unobserved infant universe between the formation of the Cosmic Microwave Background around $z \approx 1100$ and the first galaxies around $z\approx 30$. A detection of the…
We present an updated estimate of the cosmic radio background (CRB) and the corresponding attenuation lengths for ultra-high energy photons. This new estimate provides associated uncertainties as a function of frequency derived from…
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…
The dark ages 21-cm signal is a powerful tool for precision cosmology and probing new physics. We study two non-standard models: an excess radio background (ERB) model (possibly generated by dark matter decay) and the millicharged dark…
Spectral measurements of the 21 cm monopole background have the promise of revealing the bulk energetic properties and ionization state of our universe from z ~ 6-30. Synchrotron foregrounds are orders of magnitude larger than the…
In the last few years ARCADE 2, combined with older experiments, has detected an additional radio background, measured as a temperature and ranging in frequency from 22 MHz to 10 GHz, not accounted for by known radio sources and the cosmic…
Efforts are being made to observe the 21-cm signal from the 'cosmic dawn' using sky-averaged observations with individual radio dipoles. In this paper, we develop a model of the observations accounting for the 21-cm signal, foregrounds, and…
The absolute temperature of the cosmic microwave background (CMB) has been measured at a frequency of 1280 MHz. The observation was made with a modified version of the L-band receiver used in the Giant Metre wavelength Radio Telescope…
A new determination of the upper limit to the cosmic diffuse background radiation, at ~110 nm, of 300 photons s-1 cm-2 sr-1 nm-1, is placed in the context of diffuse background measurements across the entire electromagnetic spectrum,…
The low frequency tail of the CMB spectrum, down along the radio range (~1 GHz), may carry weak spectral distortions which are fingerprints of processes occurred during different epochs of the thermal history of the Universe, from z~3\times…
Distortions of the observed cosmic microwave background imprinted by the Sunyaev-Zel'dovich effect toward massive galaxy clusters due to inverse Compton scattering of microwave photons by high-energy electrons provide a direct measurement…
Studies of the cosmic dark ages ($30 \lesssim z \lesssim 150$) using the highly redshifted 21 cm line of neutral hydrogen offer unparalleled amounts of cosmological information, and recent years have seen the refinement of concepts for such…