相关论文: Foregrounds and experiments below 33GHz

Satellite CMB anisotropy missions and new generation of balloon-borne and ground experiments, make use of complex multi-frequency instruments at the focus of a meter class telescope. Between 70 GHz and 300 GHz, where foreground…

The comparison of optical reference frequency signals over free-space optical links is limited by the relative motion between local and remote sites. For ground to low earth orbit comparison, the expected Doppler shift and Doppler rate…

Radio interferometers are well suited to studies of both total intensity and polarized intensity fluctuations of the cosmic microwave background radiation, and they have been used successfully in measurements of both the primary and…

We present ALMA observations at 233, 678, and 870 GHz of the Galactic Center black hole, Sagittarius A*. These observations reveal a flat spectrum over this frequency range with spectral index $\alpha \approx -0.3$, where the flux density…

We present 33\,GHz photometry of 103 galaxy nuclei and extranuclear star-forming complexes taken with the Green Bank Telescope (GBT) as part of the Star Formation in Radio Survey (SFRS). Among the sources without evidence for an AGN, and…

The brightness of a light source defines its applicability to nonlinear phenomena in science. Bright low frequency terahertz (< 5THz) radiation confined to a diffraction-limited spot size is a present hurdle due to the broad bandwidth and…

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…

We present a detailed analysis of the cosmic microwave background structure in the Tenerife Dec=+40 degrees data. The effect of local atmospheric contributions on the derived fluctuation amplitude is considered, resulting in an improved…

Nulling interferometry, a powerful technique for high-resolution imaging of the close neighbourhood of bright astrophysical objets, is currently considered for future space missions such as Darwin or the Terrestrial Planet Finder…

The pre-main sequence binary system V773 Tau A shows remarkable flaring activity around periastron passage. Here, we present the observation of such a flare at a wavelength of 3 mm (90 GHz) performed with the Plateau de Bure Interferometer.…

The recent observations of 50 TeV gamma radiation by HEGRA have the potential of determining the extragalactic flux of infrared radiation. The fact that radiation is observed in the range between 30 and 100 TeV sets an upper limit on the…

Neutral hydrogen ($\rm{HI}$) $21$-cm intensity mapping (IM) offers an efficient technique for mapping the large-scale structures in the universe. We introduce the 'Cross' Tapered Gridded Estimator (Cross TGE), which cross-correlates two…

We investigate a number of potential foregrounds for an ambitious goal of future radio telescopes such as the Square Kilometer Array (SKA) and Low Frequency Array (LOFAR): spatial tomography of neutral gas at high redshift in 21cm emission.…

Primary proton spectrum in the energy range $5-10^3$ TeV is reconstructed from the sea level muon spectrum with the use of QGSJET01 and SYBILL2.1 interaction models. Heavier nuclei are taken in accordance with the direct measurements data,…

Foreground removal is a major challenge for detecting the redshifted 21-cm neutral hydrogen (HI) signal from the Epoch of Reionization (EoR). We have used 150 MHz GMRT observations to characterize the statistical properties of the…

This paper demonstrates how spectrum up to 1 THz will support mobile communications beyond 5G in the coming decades. Results of rooftop surrogate satellite/tower base station measurements at 140 GHz show the natural isolation between…

Observations of the 21cm Epoch of Reionization (EoR) signal are dominated by Galactic and extragalactic foregrounds. The need for foreground removal has led to the development of two main techniques, often referred to as "foreground…

The diffuse Galactic synchrotron emission (DGSE) is the most important diffuse foreground component for future cosmological 21-cm observations. The DGSE is also an important probe of the cosmic ray electron and magnetic field distributions…

We report the observation of fringes from a three grating electron interferometer. Interference fringes have been observed at low energies ranging from 6 keV to 10 keV. Contrasts of up to 25% are recorded and exceed the maximal contrast of…

The sky-averaged, or global, background of redshifted $21$ cm radiation is expected to be a rich source of information on cosmological reheating and reionizaton. However, measuring the signal is technically challenging: one must extract a…