نتایج جستجو برای: radio sensitivity non coherent

تعداد نتایج: 1744023  

Journal: :Universe 2021

Fast radio bursts (FRBs) are recently discovered mysterious single pulses of emission, mostly coming from cosmological distances (∼1 Gpc). Their short duration, ∼1 ms, and large luminosity demonstrate coherent emission. I review the basic physics emission mechanisms proposed for FRBs. In particular, discuss curvature bunches, synchrotron maser, waves by variable currents during magnetic reconne...

2004
TIM HUEGE

Radio emission from cosmic ray air showers has the potential to become an additional, cost-effective observing technique for cosmic ray research, being largely complementary to the well-established particle detector and air fluorescence techniques. We present Monte Carlo simulatios of radio emission from extensive air showers in the scheme of coherent geosynchrotron radiation from electron-posi...

2016
Garima Gupta Rajender Kumar

Underwater acoustic channels are band-limited and reverberant, posing many obstacles to reliable, phase-coherent acoustic communications. In terrestrial wireless sensor networks, the nodes use radio frequency (RF) to build up the communication. In underwater environments, due to water absorption, radio wave does not work well. Compared to radio waves, sound has superior propagation characterist...

2003
C. A. Katz J. N. Hewitt C. B. Moore

We have constructed and operated the Survey for Transient Astronomical Radio Emission (STARE) to detect transient astronomical radio emission at 611 MHz originating from the sky over the northeastern United States. The system is sensitive to transient events on timescales of 0.125 s to a few minutes, with a typical zenith flux density detection threshold of approximately 27 kJy. During 18 month...

1999
D. M. Worrall

X-ray emission traces the gaseous environments of radio sources. The medium must be present for jet confinement, but what are its influence on jet fuelling, dynamics, propagation, and disruption? The observational situation is both complicated and enriched by radio sources being multi-component X-ray emitters, with several possible regions of non-thermal emission. Recent work, primarily based o...

ژورنال: پژوهشنامه اخلاق 2014

Ethics of speech is one of the most important ethical features in a desirable society which is indebted to lots of factors such as cultural and social ones in general and in particular to administrators of culture and education. In this respect, as an auditory media, radio can play a key role in making culture of verbal ethics and spread it to individuals and societies. Direct and indirect huma...

2011
V. Heesen

We exploit the vastly increased sensitivity of the Expanded Very Large Array (EVLA) to study the radio continuum and polarization properties of the post– starburst, dwarf irregular galaxy IC10 at 6 cm, at a linear resolution of ∼ 50 pc. We find close agreement between radio continuum and Hα emission, from the brightest H II regions to the weaker emission in the disk. A quantitative analysis sho...

2008
G. Hallinan

We report on radio observations of the M8.5 dwarf LSR J1835+3259 and the L3.5 dwarf 2MASS J00361617+1821104, which provide the strongest evidence to date that the electron cyclotron maser instability is the dominant mechanism producing radio emission in the magnetospheres of ultracool dwarfs. As has previously been reported for the M9 dwarf TVLM 513-46546, periodic pulses of 100% circularly pol...

Journal: :Physical review letters 2001
J Huang N Eradat M E Raikh Z V Vardeny A A Zakhidov R H Baughman

We studied coherent backscattering (CBS) of light from opal photonic crystals with incomplete band gaps. We observed a dramatic broadening of the CBS cone for incident angles close to the Bragg condition in the crystals. We modify the conventional CBS theory to incorporate Bragg attenuation resulting from the photonic band structure. By fitting the CBS data with the modified theory, we extract ...

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