scholarly journals The Phase Stability of Micropulses from PSR 1133+16

1992 ◽  
Vol 128 ◽  
pp. 340-342
Author(s):  
V. D. Pugachev ◽  
Yu. P. Shitov ◽  
A. G. Soin
Keyword(s):  
Radio Emission ◽  
Temporal Variation ◽  
Phase Stability ◽  
Emission Intensity ◽  
Short Pulse ◽  
Narrow Beam ◽  
Radiation Beam ◽  
The Individual ◽  
Usual Scale ◽  
Beam Rotation

As is very well known, there are two different kinds of time structure of the individual pulses of pulsars. There are microstructures with time scales less than 1 ms and subpulse structures, the usual scale of which is of the order of 10 ms. Subpulses are a result of the radiation beam rotation and in many cases demonstrate some regularity of arrival phases. In contrast, microstructure looks rather like a short pulse of noise with random phases of micropulse appearance in the radio emission window of the pulsar. Because the appearance phases of micropulses are random in the pulsar period, it is very difficult to establish what the fundamental character of these micropulses is: are they a temporal variation of radio emission intensity or the result of narrow beam rotation?

SIMULATION OF RADIO SIGNALS FROM 1-10 TeV AIR SHOWERS USING EGSNRC

2006 ◽  
Vol 21 (supp01) ◽  
pp. 65-69 ◽  
Author(s):  
R. Engel ◽  
N. N. Kalmykov ◽  
A. A. Konstantinov
Keyword(s):  
Monte Carlo ◽  
Radio Emission ◽  
Monte Carlo Simulations ◽  
Frequency Spectrum ◽  
Radial Dependence ◽  
Frequency Range ◽  
Air Showers ◽  
Shower Development ◽  
Radio Signals ◽  
The Individual

Cherenkov and geosynchrotron radiation are considered as two fundamental mechanisms of the radio emission generated by extensive air showers (EAS). The code EGSnrc is used for Monte-Carlo simulations of the individual shower development. Calculations of the radial dependence and frequency spectrum of the emitted radiation are performed for the LOPES experiment frequency range.

scholarly journals The auroral radio emission of the magnetic B-type star ρ OphC

2020 ◽  
Vol 499 (1) ◽  
pp. L72-L76
Author(s):  
P Leto ◽  
C Trigilio ◽  
C S Buemi ◽  
F Leone ◽  
I Pillitteri ◽  
...  
Keyword(s):  
Radio Emission ◽  
Indirect Evidence ◽  
Magnetic Star ◽  
Early Type ◽  
Radiation Beam ◽  
Polar Caps ◽  
Thermal Radio ◽  
Thermal Radio Emission ◽  
Early Type Stars ◽  
Rotational Phase

ABSTRACT The non-thermal radio emission of main-sequence early-type stars is a signature of stellar magnetism. We present multiwavelength (1.6–16.7 GHz) ATCA measurements of the early-type magnetic star ρ OphC, which is a flat-spectrum non-thermal radio source. The ρ OphC radio emission is partially circularly polarized with a steep spectral dependence: the fraction of polarized emission is about $60{{\ \rm per\ cent}}$ at the lowest frequency sub-band (1.6 GHz) while is undetected at 16.7 GHz. This is clear evidence of coherent Auroral Radio Emission (ARE) from the ρ OphC magnetosphere. Interestingly, the detection of the ρ OphC’s ARE is not related to a peculiar rotational phase. This is a consequence of the stellar geometry, which makes the strongly anisotropic radiation beam of the amplified radiation always pointed towards Earth. The circular polarization sign evidences mainly amplification of the ordinary mode of the electromagnetic wave, consistent with a maser amplification occurring within dense regions. This is indirect evidence of the plasma evaporation from the polar caps, a phenomenon responsible for the thermal X-ray aurorae. ρ OphC is not the first early-type magnetic star showing the O-mode dominated ARE but is the first star with the ARE always on view.

Dual Pump Femtosecond Laser Induced Plasma

2008 ◽  
Author(s):  
Meg Mahat ◽  
Tae Y. Choi ◽  
Nasrasadani Seifolah ◽  
Arup Neogi
Keyword(s):  
Emission Intensity ◽  
Short Pulse ◽  
Single Pulse ◽  
Atomic Emission ◽  
Dielectric Materials ◽  
Pulse Excitation ◽  
Time Resolved ◽  
Breakdown Spectroscopy ◽  
Short Pulse Laser ◽  
Ultra Short Pulse

Laser-induced breakdown spectroscopy (LIBS) can provide a noncontact way of inspecting a specimen including distinct signature of atomic composition of the sample. Ultra-short pulse laser enables characterization of any materials by utilizing the multiphoton process, which is a dominant carrier generation mechanism for dielectric materials. Additionally, femtosecond LIBS yields low background and better defined atomic lines than the nanosecond LIBS. We have performed a time-resolved emission intensity measurement for an iron oxide (Fe3O4, magnetite). The emission intensity has the peak value at 100 ps time delay, signifying that the succeeding pump beam is interacting with the plasma generated in the vicinity of the sample by the preceding beam. The dual pulses significantly enhance the atomic emission as compared to single pulse excitation and enables ultrafast time-resolved spectroscopy.

General Theory of Narrow Beam Rotation Tomography

1961 ◽  
Vol 55 (6) ◽  
pp. 458-464 ◽  
Author(s):  
Pekka Soila
Keyword(s):  
General Theory ◽  
Narrow Beam ◽  
Beam Rotation

Form Distortion in Narrow Beam Rotation Radiography

1975 ◽  
Vol 16 (6) ◽  
pp. 565-571 ◽  
Author(s):  
Anders Sjöblom ◽  
Kjell-Arne Sämfors ◽  
Ulf Welander
Keyword(s):  
Narrow Beam ◽  
Beam Rotation

General Theory of Narrow Beam Rotation Tomography

1961 ◽  
Vol Original Series, Volume 55 (6) ◽  
pp. 458-464
Author(s):  
P. Soila
Keyword(s):  
General Theory ◽  
Narrow Beam ◽  
Beam Rotation

Brightness and Temporal Variation of Radio Emission from Galactic OH

Nature ◽  
1967 ◽  
Vol 214 (5089) ◽  
pp. 689-690 ◽  
Author(s):  
A. H. COOK
Keyword(s):  
Radio Emission ◽  
Temporal Variation

scholarly journals Radio Emission from Binary Stars in the AB Doradus Moving Group

2015 ◽  
Vol 10 (S314) ◽  
pp. 117-118
Author(s):  
R. Azulay ◽  
J.C. Guirado ◽  
J.M. Marcaide ◽  
I. Martí-Vidal ◽  
E. Ros
Keyword(s):  
Radio Emission ◽  
Binary Stars ◽  
Binary Systems ◽  
Main Sequence ◽  
Precise Determination ◽  
Orbital Parameters ◽  
Long Baseline ◽  
Low Mass ◽  
The Individual ◽  
Dynamical Masses

AbstractPrecise determination of dynamical masses of pre-main-sequence stars is essential for calibrating stellar evolution models, that are widely used to derive theoretical masses of young low-mass objects. We have determined the individual masses of the pair AB Dor Ba/Bb using Australian Long Baseline Array observations and archive infrared data, as part of a larger program directed to monitor binary systems in the AB Doradus moving group. We have detected, for the first time, compact radio emission from both stars. This has allowed us to determine the orbital parameters of both the relative and absolute orbits and, consequently, their individual dynamical masses: 0.28±0.05 M⊙ and 0.25±0.05 M⊙. Comparisons of the dynamical masses with the prediction of pre-main-sequence (PMS) evolutionary models show that the models underpredict the dynamical masses of the binary components Ba and Bb by 10–30% and 10–40%, respectively.

Blurring and Layer Thickness in Narrow Beam Rotation Radiography

1977 ◽  
Vol 18 (6) ◽  
pp. 705-714 ◽  
Author(s):  
U. Welander ◽  
G. Wickman
Keyword(s):  
Layer Thickness ◽  
Narrow Beam ◽  
Beam Rotation
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