Resonance effects in thermal radio emission of water surface

1986 ◽  
Vol 29 (4) ◽  
pp. 279-283 ◽  
Author(s):  
V. E. Gershenzon ◽  
V. G. Irisov ◽  
Yu. G. Trokhimovskii ◽  
V. S. �tkin
Keyword(s):  
Radio Emission ◽  
Water Surface ◽  
Resonance Effects ◽  
Thermal Radio ◽  
Thermal Radio Emission

scholarly journals Non-thermal radio emission from O-type stars

2007 ◽  
Vol 464 (2) ◽  
pp. 701-708 ◽  
Author(s):  
R. Blomme ◽  
M. De Becker ◽  
M. C. Runacres ◽  
S. Van Loo ◽  
D. Y. A. Setia Gunawan
Keyword(s):  
Radio Emission ◽  
Thermal Radio ◽  
Thermal Radio Emission

scholarly journals Erratum: Constraining the nature of DG Tau A's thermal and non-thermal radio emission

2018 ◽  
Vol 483 (3) ◽  
pp. 4085-4085
Author(s):  
S J D Purser ◽  
R E Ainsworth ◽  
T P Ray ◽  
D A Green ◽  
A M Taylor ◽  
...  
Keyword(s):  
Radio Emission ◽  
Thermal Radio ◽  
Thermal Radio Emission

scholarly journals Non-thermal radio emission in Wolf-Rayet stars: is binarity a pre-requisite?

1999 ◽  
Vol 193 ◽  
pp. 348-349
Author(s):  
Sean M. Dougherty
Keyword(s):  
Radio Emission ◽  
Spectral Index ◽  
Thermal Emission ◽  
Radio Observations ◽  
Thermal Radio ◽  
Thermal Radio Emission ◽  
Thermal Emitters

Radio observations of Wolf-Rayet stars currently available in the literature are examined to determine whether binarity is a common feature of WR systems with non-thermal emission. Among 24 stars with observed spectral index values, seven are definite non-thermal emitters, and six others possibly have composite thermal/non-thermal spectra. Stellar companions have been identified in 71% of the non-thermal emitters, strongly supporting a link between non-thermal emission and binarity.

scholarly journals The nearby extreme accretion and feedback system PDS 456: finding a complex radio-emitting nucleus

2020 ◽  
Vol 500 (2) ◽  
pp. 2620-2626
Author(s):  
Jun Yang ◽  
Zsolt Paragi ◽  
Emanuele Nardini ◽  
Willem A Baan ◽  
Lulu Fan ◽  
...  
Keyword(s):  
Black Hole ◽  
Radio Emission ◽  
High Speed ◽  
Feedback System ◽  
Emission Region ◽  
Starburst Galaxy ◽  
Massive Black Hole ◽  
Star Forming ◽  
Thermal Radio ◽  
Thermal Radio Emission

ABSTRACT When a black hole accretes close to the Eddington limit, the astrophysical jet is often accompanied by radiatively driven, wide-aperture and mildly relativistic winds. Powerful winds can produce significant non-thermal radio emission via shocks. Among the nearby critical accretion quasars, PDS 456 has a very massive black hole (about 1 billion solar masses), shows a significant star-forming activity (about 70 solar masses per year), and hosts exceptionally energetic X-ray winds (power up to 20 per cent of the Eddington luminosity). To probe the radio activity in this extreme accretion and feedback system, we performed very long baseline interferometric (VLBI) observations of PDS 456 at 1.66 GHz with the European VLBI Network and the enhanced Multi-Element Remotely Linked Interferometry Network. We find a rarely seen complex radio-emitting nucleus consisting of a collimated jet and an extended non-thermal radio emission region. The diffuse emission region has a size of about 360 pc and a radio luminosity about three times higher than that of the nearby extreme starburst galaxy Arp 220. The powerful nuclear radio activity could result either from a relic jet with a peculiar geometry (nearly along the line of sight) or more likely from diffuse shocks formed naturally by the existing high-speed winds impacting on high-density star-forming regions.

scholarly journals Numerical simulations of unbounded cyclotron-maser emissions

2013 ◽  
Vol 79 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
DAVID C. SPEIRS ◽  
S. L. McCONVILLE ◽  
K. M. GILLESPIE ◽  
A. D. R. PHELPS ◽  
K. RONALD
Keyword(s):  
Radio Emission ◽  
Numerical Simulations ◽  
Source Region ◽  
Radio Emissions ◽  
Cyclotron Maser ◽  
Thermal Radio ◽  
Thermal Radio Emission ◽  
Electron Cyclotron Masers ◽  
Coupling Characteristics ◽  
Significant Bearing

AbstractNumerical simulations have been conducted to study the spatial growth rate and emission topology of the cyclotron-maser instability responsible for stellar/planetary auroral magnetospheric radio emission and intense non-thermal radio emission in other astrophysical contexts. These simulations were carried out in an unconstrained geometry, so that the conditions existing within the source region of some natural electron cyclotron masers could be more closely modelled. The results have significant bearing on the radiation propagation and coupling characteristics within the source region of such non-thermal radio emissions.

scholarly journals Constraining the nature of DG Tau A’s thermal and non-thermal radio emission

2018 ◽  
Vol 481 (4) ◽  
pp. 5532-5542 ◽  
Author(s):  
S J D Purser ◽  
R E Ainsworth ◽  
T P Ray ◽  
D A Green ◽  
A M Taylor ◽  
...  
Keyword(s):  
Radio Emission ◽  
Thermal Radio ◽  
Thermal Radio Emission

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.

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