Special purpose image display devices and techniques at the National Radio Astronomy Observatory
نویسندگان
چکیده
منابع مشابه
National Radio Astronomy Observatory
As part of an initiative to reduce the size, weight, and complexity of radio astronomy receivers and to place the conversion from analog to digital signals as close to the telescope feed as possible, a prototype single-conversion, sideband-separating mixer receiver with a tunable local oscillator (LO) between 5 and 9 GHz has been built and tested. After straightforward gain and phase calibratio...
متن کاملNational Radio Astronomy Observatory
Measurements of microwave attenuation at room temperature and 4.2 K have been performed on some conductors commonly used in receiver input circuits. The reduction in loss on cooling is substantial, particularly for copper and plated gold, both of which showed a factor of 3 loss reduction. Copper passivated with benzotriazole shows the same loss as without passivation. The residual resistivity r...
متن کاملNational Radio Astronomy Observatory
The existing waveguide interface standards are generally found to be unsatisfactory above 110 GHz. An improved interface is proposed which is backward-compatible with the MIL-DTL-3922/67C standard and most of its higher-frequency variants. As there are currently no standard waveguide bands above 325 GHz, an extended set of bands is recommended for operation to 1100 GHz. Index Terms — Waveguides...
متن کاملNational Optical Astronomy Observatory
AGN are elusive objects across that are visible across the electromagnetic spectrum. Currently, there is no complete picture of AGN formation and evolution in galaxy clusters. A general understanding of the AGN population has been impeded by cluster and selection biases and recent studies have shown that there is a large population of obscured or optically unremarkable AGN in galaxy clusters. T...
متن کاملNational Optical Astronomy Observatory
We use an X-ray stacking technique to investigate the evolution of the mean X-ray luminosity of ∼21,000 red galaxies at 0.3 ≤ z < 0.9 as a function of their stellar mass and redshift. The red galaxies are selected from the 9.3 deg 2 Boötes field of the NOAO Deep Wide-Field Survey (NDWFS). The mean X-ray luminosity is an order of magnitude larger than we would expect from stellar sources alone a...
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ژورنال
عنوان ژورنال: Computers in Physics
سال: 1989
ISSN: 0894-1866
DOI: 10.1063/1.168352