ISSN:
1572-946X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract It is shown that X-ray radiation of neutron stars with magnetic fieldsB=1011–1013 G near cyclotron resonancesω=sω B (s=1,2,...) is deeply affected by such quantum effects as electron-positron vacuum polarization (significant at V=3×1028 n e −1 (B/B C 4)≳1, whereB C =4.4×1013G), the quantizing character of the magnetic field (significant atV=3 x 1028 n e −1 (B/B c)4≳1 whereB c =4.4 x 1013G), the non-harmonic character of the Landau levels, and the quantum recoil of electrons. The latter two factors shift the resonances by the frequency −s 2 ω B (B/2B c )sin2ϑ, ϑ being the angle between the direction of radiation propagation and the magnetic field. IfV≪V 0 (for ϑ∼1,V 0∼β−1=(mc 2/2T)1/2), the normal mode (NM) polarizations, as well as the absorption coefficientk 1 of the extraordinary NM in the Doppler core of the first resonance (|ω−ω| ≲ωBβ cos ϑ), is only slightly affected by varyingb and/orV, whereas for the ordinary NM (at ϑ∼1)k 2∼k 1 β 2[b + (3 + tan2ϑ−2V)2]≪k 1. For sufficiently largeb and/orV the quantum effects amplify resonant absorption of the ordinary NM atω∼ω B , with spin-flip transitions playing a major role atb≳1+V 2. IfV∼V 0, the coefficientsk 1 andk 2 in the Doppler core of the resonance are of the same order and acquire some peculiar features (shifts, intersections, etc.), with the NM polarizations depending sharply on ω and being strongly non-orthogonal. AtV≫V 0,k 2=k 1(cos2 ϑ+B/2B C ) and the polarizations are almost linear. Near high resonances (s≥2), as a rule,k 1,2α(1 + b) s−1 β 2s−3 i.e., absorption increases withb due to replacement of the thermal energy of the transverse motion of electron,T, by the magnetic energyħω B . The above effects should be taken into account for an interpretation of observational data on X-ray pulsars (e.g., Her X-1) and other X-ray sources associated with neutron stars.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00642366
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