Doppler Shift model to explain the Cyclotron Line Variability in X - Ray
نویسنده
چکیده
A simple model to explain the phase-dependence of the cyclotron absorption line observed in many X-Ray pulsars is presented. It includes several relativistic effects, namely gravitational redshift, gravitational light deflection, and – most important – doppler shift of the photon energy in the infalling plasma. It is shown that previous estimates of neutron star magnetic fields neglecting the last effect give results which are too small by about a factor of two. Finally the developed equations are used to determine the neutron star radius and magnetic field of Her X-1, but the large uncertainties in the geometry prevent the results from seriously constraining the parameters.
منابع مشابه
The cyclotron emission of anisotropic electrons in the X-ray pulsars
The spectrum of cyclotron radiation is calculated for anisotropically distributed relativistic electrons with a nonrelativistic velocity scattering across the magnetic field. It is shown that if such electrons are responsible for a formation of the ”cyclotron” line in the spectrum of Her X-1, then the value of its magnetic field (3 − 6) · 10 Gs following from this interpretation is in a good ag...
متن کاملResonant Cyclotron Scattering in Three Dimensions and the Quiescent Non-thermal X-ray Emission of Magnetars
Although the surface of a magnetar is a source of bright thermal X-rays, its spectrum contains substantial non-thermal components. The X-ray emission is pulsed, with pulsed fractions that can be as high as ∼ 70%. Several properties of magnetars indicate the presence of persistent, static currents flowing across the stellar surface and closing within the magnetosphere. The charges supporting the...
متن کاملI-47: Doppler Ultrasound Diagnosis of Intrauterine Lesions
Background In patients with abnormal uterine bleeding, transvaginal ultrasound (TVS) is the first-line diagnostic approach to exclude endometrial pathology. If a thickened endometrium suggests endometrial pathology, sonohysterography, office hysteroscopy or dilatation and curettage are the second-line tests preferred, depending on availability and on the suspected pathology, to exclude malignan...
متن کاملDoppler Imaging of 44 ι Boo with Chandra
Chandra High-Energy Transmission Grating observations of the bright eclipsing contact binary 44ι Boo show X-ray line profiles which are Doppler-shifted by orbital motions. The X-ray emission spectrum contains a multitude of lines superimposed on a weak continuum, with strong lines of O VIII, Ne X, Fe XVII, and Mg XII. The profiles of these lines from the total observed spectrum show Doppler-bro...
متن کاملLuminosity-dependent changes of the cyclotron line energy and spectral hardness in Cep X-4
Context. X-ray spectra of accreting pulsars are generally observed to vary with their X-ray luminosity. In particular, the hardness of the X-ray continuum is found to depend on luminosity. In a few sources, the correlation between the energy of the cyclotron resonance scattering feature (CRSF) and the luminosity is clear. Different types (signs) of the correlation are believed to reflect differ...
متن کامل