scholarly journals Radio Emission from a Young Supernova Remnant Interacting with an Interstellar Cloud: Magnetohydrodynamic Simulation with Relativistic Electrons

1999 ◽  
Vol 511 (2) ◽  
pp. 774-791 ◽  
Author(s):  
Byung‐Il Jun ◽  
T. W. Jones
2021 ◽  
Vol 65 (8) ◽  
pp. 645-656
Author(s):  
V. P. Ivanov ◽  
A. V. Ipatov ◽  
I. A. Rahimov ◽  
T. S. Andreeva

Abstract The spectrum of G11.2-0.3 has been refined by bringing the published intensity measurements to the “artificial moon” flux scale, and the dynamics of its changes on different time scales from 0.4 to more than ~50 years has been investigated. An increase in the fluxes of radio emission of G11.2-0.3 for ≥30 years at 3 cm $$ \leqslant \lambda \leqslant 375$$ cm with a frequency dependence was found: the average rate of changes decreases proportionally to $$\log(f)$$, and at frequencies $$f \geqslant 10$$ GHz, the increase gave way to a decrease. Measurements with the RT-32 radio telescope of the Svetloe observatory (IAA RAS) in 2013–2019 showed a decrease in fluxes of G11.2-0.3 against the background of rapid nonstationary changes with an average rate of ($$ - 5.4 \pm 6.6$$) %/year at a wavelength $$\lambda = 6.2$$cm and ($$ - 1.5 \pm 0.9)$$ %/year at $$\lambda = 3.5$$ cm. The stages of growth and decline of fluxes are separated by an epoch $$2016.9 \pm 0.6$$. The spectrum of G11.2-0.3 is the spectra sum of the shell and the plerion, with each of its parameters determined by the method developed for the 1972.5 epoch. The values of the spectral indices α1 of the shell and α2 of PWN are obtained: $$\alpha {{1}_{{1972}}} = 0.77$$ and $$\alpha {{2}_{{1972}}} = 0.251$$. The dynamics of radio emission from the remnant reflects the scenario of interaction between the shock wave and CSM. Possible reasons for evolutionary and non-stationary changes are discussed.


Author(s):  
Paula Benaglia ◽  
Santiago del Palacio ◽  
Christopher Hales ◽  
Marcelo E Colazo

Abstract We present a deep radio-polarimetric observation of the stellar bow shock EB27 associated to the massive star BD+43○3654. This is the only stellar bow shock confirmed to have non-thermal radio emission. We used the Jansky Very Large Array in S band (2–4 GHz) to test whether this synchrotron emission is polarised. The unprecedented sensitivity achieved allowed us to map even the fainter regions of the bow shock, revealing that the more diffuse emission is steeper and the bow shock brighter than previously reported. No linear polarisation is detected in the bow shock above 0.5%, although we detected polarised emission from two southern sources, probably extragalactic in nature. We modeled the intensity and morphology of the radio emission to better constrain the magnetic field and injected power in relativistic electrons. Finally, we derived a set of more precise parameters for the system EB27–BD+43○3654 using Gaia Early Data Release 3, including the spatial velocity. The new trajectory, back in time, intersects the core of the Cyg OB2 association.


1998 ◽  
Vol 13 (16) ◽  
pp. 1253-1264 ◽  
Author(s):  
LUIS P. NEIRA CERVILLERA ◽  
ROBERTO O. AQUILANO ◽  
HECTOR VUCETICH

In this letter we present a general relativistic star with strange matter to explain in a young supernova remnant the radial millisecond oscillations. The results confirm previous conclusions.


1967 ◽  
Vol 20 (3) ◽  
pp. 297 ◽  
Author(s):  
ER Hill

Radio evidence for two new supernova remnants in the Southern Milky Way is presented. Some new observations of the known supernova remnant, source 1439-62, and of the Rosette nebula, a shell source but not a supernova remnant, are also presented. The problem of finding model shells to fit the radio observations is considered and it is shown that the radio emission from 1439-62 is unlikely to originate in a shell with spherical symmetry.


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