Wilms J (2007)
Publication Status: Published
Publication Type: Conference contribution
Publication year: 2007
Book Volume: 622
Pages Range: 465-+
We present new results on the cyclotron resonance scattering feature (CRSF) in the X-ray spectrum of the binary X-ray pulsar Her X-1 from repeated observations by RXTE between 2000 and 2005, together with earlier results from RXTE and historical data. The centroid line energy E, in pulse phase averaged spectra shows considerable variation, both in the long-term historical development as well as during the time of the RXTE observations. Using RXTE data only, we find that the cyclotron line energy correlates with the observed maximum flux of the corresponding 35 day Main-On state, as measured by the RXTE/ASM. Contrary to what is observed in some high luminosity transient pulsars, the correlation found here is positive, with a change of similar to 5% in E-c for a change of a factor of two in X-ray flux. We suggest that this behaviour is expected in the case of sub-Eddington accretion and present a calculation of a quantitative estimate.
APA:
Wilms, J. (2007). Variable cyclotron line in her X-1. (pp. 465-+).
MLA:
Wilms, Jörn. "Variable cyclotron line in her X-1." 2007. 465-+.
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