Sub-rotation and Super-rotation in Pulsar Magnetospheres

1981 ◽  
Vol 34 (1) ◽  
pp. 97
Author(s):  
RR Burman

For magnetospheric species that are nonrelativistic at the stellar surface in the general oblique rotator model, it is shown that a ondissipative flow branch which is sub-rotating when near the star remains sub-rotating everywhere, but that one which is super-rotating when near the star can become sub-rotating inside the light cylinder. Hence, both flow branches can cross the light cylinder and remain valid outside it.

1988 ◽  
Vol 132 ◽  
pp. 329-332
Author(s):  
C. Mégessier ◽  
T. Lanz ◽  
J. D. Landstreet

SiII lines of magnetic Bp-Si stars in open clusters have been observed with the CAT (ESO) in order to get a mapping of the Silicon abundance distribution over the stellar surface, in the frame of the oblique rotator model. We point out the influence of the Zeeman splitting and of the abundance inhomogeneities on the line profiles.


1986 ◽  
Vol 90 ◽  
pp. 141-147
Author(s):  
I. Vincze

Abstract53 Cam is a well-known magnetic, spectroscopic and photometric variable star of Ap-type. The line intensities of 53 Cam show a variation, which has a period of 8h. The oblique-rotator model, developed mathematically by Deutsch /1970/, has been applied for the spectral and magnetic variations. In this paper, using Deutsch’s method, the distribution of CrII, EuII, TiII, SrII on the stellar surface is analysed and the relation between the abundance of elements and the magnetic structure is studied. The Laplace and Fourier coefficients for each elements have been computed and also the distribution of the elements at the stellar surface has been drawn by a Sinclair ZX Spectrum personal computer.


1976 ◽  
Vol 32 ◽  
pp. 577-588
Author(s):  
C. Mégessier ◽  
V. Khokhlova ◽  
T. Ryabchikova

My talk will be on the oblique rotator model which was first proposed by Stibbs (1950), and since received success and further developments. I shall present two different attempts at describing a star according to this model and the first results obtained in the framework of a Russian-French collaboration in order to test the precision of the two methods. The aim is to give the best possible representation of the element distributions on the Ap stellar surfaces. The first method is the mathematical formulation proposed by Deutsch (1958-1970) and applied by Deutsch (1958) to HD 125248, by Pyper (1969) to α2CVn and by Mégessier (1975) to 108 Aqr. The other one was proposed by Khokhlova (1974) and used by her group.


1976 ◽  
Vol 32 ◽  
pp. 233-254
Author(s):  
H. M. Maitzen

Ap stars are peculiar in many aspects. During this century astronomers have been trying to collect data about these and have found a confusing variety of peculiar behaviour even from star to star that Struve stated in 1942 that at least we know that these phenomena are not supernatural. A real push to start deeper theoretical work on Ap stars was given by an additional observational evidence, namely the discovery of magnetic fields on these stars by Babcock (1947). This originated the concept that magnetic fields are the cause for spectroscopic and photometric peculiarities. Great leaps for the astronomical mankind were the Oblique Rotator model by Stibbs (1950) and Deutsch (1954), which by the way provided mathematical tools for the later handling pulsar geometries, anti the discovery of phase coincidence of the extrema of magnetic field, spectrum and photometric variations (e.g. Jarzebowski, 1960).


1974 ◽  
Vol 166 (1) ◽  
pp. 113-121 ◽  
Author(s):  
G. T. Bath ◽  
W. D. Evans ◽  
J. E. Pringle

1970 ◽  
Vol 4 ◽  
pp. 269-273
Author(s):  
L. Mestel ◽  
C. S. Selley

This work investigates the dynamical evolution of a rotating magnetic star which drives a stellar wind. The basic magnetic field of the star is supposed symmetric about an axis, which is inclined at an angle X to the rotation axis k (Figure 1). We adopt the familiar equations of an inviscid perfectly conducting gas. In a steady state, the velocity as seen in a frame rotating with the star is taken as


1999 ◽  
Vol 169 ◽  
pp. 178-186
Author(s):  
Steven N. Shore

AbstractThe upper main sequence chemically peculiar (CP) stars display evidence of trapped circumstellar gas and nonspherical outflows. These stars are also known to possess strong magnetic fields that are often highly inclined to the rotational axis. Their phenomenology can be understood by using the oblique rotator model, which has successfully accounted for the observed behavior of the cooler CP stars. This paper reviews some features of the oblique rotator model, in which the magnetic field is assumed to provide a rigid framework for the structuring of the stellar and circumstellar gas. Corotation of circumstellar plasma is enforced out to the Alfven radius in the magnetic equatorial plane, while for the hotter stars, a radiatively driven wind emerges from the magnetic polar caps. Some observable consequences of the model are discussed, especially the Hα and ultraviolet resonance line absorption and emission periodic variability that has been observed in the He-peculiar stars and nonthermal radio emission. Magnetospheres may also be present in O stars, e.g. θ1 Ori C, and in the Herbig Ae/Be stars.


1985 ◽  
Vol 6 (2) ◽  
pp. 127-129 ◽  
Author(s):  
F. Curtis Michel

AbstractRecent laboratory experiments have confirmed theoretical expectations that the aligned rotator model (Goldreich and Julian 1969) does not function in the way originally expected, if at all. These experiments confirm that the nonneutral (completely charge-separated) plasma is isolated into finite regions, which in the case of the magnetosphere about an aligned rotator means in general that there is no plasma from the neutron star to be found at the light-cylinder. Hence the interesting pulsar-like properties originally postulated no longer follow.


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