Related papers: The GBT Gain Curve at High Frequency
With the installation of the Argus 16-pixel receiver covering 75-115 GHz on the Green Bank Telescope (GBT), it is now possible to characterize the antenna beam at very high frequencies, where the use of the active surface and out-of-focus…
A well-instrumented Green Bank Telescope (GBT) operating at high frequency represents a unique scientific resource for the US community. As a filled-aperture, 100m-diameter telescope, the GBT is ideally suited to fast mapping of extended,…
We describe the successful design, implementation, and operation of a 12 GHz holography system installed on the Robert C. Byrd Green Bank Telescope (GBT). We have used a geostationary satellite beacon to construct high-resolution…
Top-gated graphene transistors operating at high frequencies (GHz) have been fabricated and their characteristics analyzed. The measured intrinsic current gain shows an ideal 1/f frequency dependence, indicating an FET-like behavior for…
Gravitational waves have predominantly been detected using interferometric techniques, with standard approaches limited to 10 kHz and with modern advancements extending this bound to 300 kHz. To explore the largely uncharted…
We present a 67--93.6 GHz spectral line survey of Orion-KL with the new 4 mm Receiver on the Green Bank Telescope (GBT). The survey reaches unprecedented depths and covers the low-frequency end of the 3 mm atmospheric window which has been…
Since the beginning of this century we have attended a blooming of the gravity-mode research thanks to the unprecedented quality of the data available, either from space with SoHO, or from the ground-based networks as BiSON or GONG. From…
In this paper, we present an upper limit of $\Omega_{\rm GW}<1.2\times 10^{8}$ on an isotropic stochastic gravitational-wave (GW) background integrated over a year in the frequency range 0.05 Hz - 1 Hz, which improves current upper limits…
The calibration procedures for data collected for Argus and the 4mm Receiver instruments on the GBT are presented. The measured beam size, aperture efficiency, and main-beam efficiency are derived for the range of observing frequencies…
As part of the GRAVITY$^{+}$ project, the near-infrared beam combiner GRAVITY and the VLTI are currently undergoing a series of significant upgrades to further improve the performance and sky coverage. The instrumental changes will be…
The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as…
We report some improvements to the gradient ascent pulse engineering (GRAPE) algorithm for optimal control of quantum systems. These include more accurate gradients, convergence acceleration using the BFGS quasi-Newton algorithm as well as…
Gravitational waves can generate electromagnetic effects inside a strong electric or magnetic field within the Standard Model and general relativity. Here we propose using a quarterly split cavity and LC(inductor and capacitor)-resonance…
The fast temporal structures and cosmological distances of gamma-ray bursts (GRBs) afford a natural laboratory for testing theories of frequency-dependent propagation of high-energy photons, as predicted for quantum gravity (QG). We…
The quantum nature of the electromagnetic field imposes a fundamental limit on the sensitivity of optical precision measurements such as spectroscopy, microscopy, and interferometry. The so-called quantum limit is set by the zero-point…
28 GHz outdoor-indoor coverage into modern office buildings with high thermal efficiency windows is found to be severely limited due to 46 dB median penetration loss at normal incidence and additional 15 dB median oblique incidence loss.…
Each satellite of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM, mission) consists of 25 SiPM based gamma-ray detectors (GRDs). Although SiPM based GRD has merits of compact size and low bias-voltage,…
The Fermi Gamma-ray Burst Monitor (GBM) has detected over 1400 Gamma-Ray Bursts (GRBs) since it began science operations in July, 2008. We use a subset of over 300 GRBs localized by instruments such as Swift, the Fermi Large Area Telescope,…
Small- and large-signal RF characteristics were measured on AlN GaN HEMTs with 80-160 nm gate length and 100-300 {\mu}m width. Consistent with the literature, current-gain cut-off frequency and maximum frequency of oscillation were found to…
With a 100mx110m off-axis paraboloid dish, the Green Bank Telescope (GBT) is the largest fully steerable radio telescope on Earth. A major challenge facing large ground-based radio telescopes is achieving sufficient pointing accuracy for…