Detection of a cyclotron line and its second harmonic in 4U1907+09
Astrophysics
2008-12-01 v1
Abstract
We report the detection of a cyclotron absorption line and its second harmonic in the average spectrum of the high mass X-ray binary 4U1907+09 observed by the BeppoSAX satellite on 1997 September 27 and 28. The broad band spectral capability of BeppoSAX allowed a good determination of the continuum against which the two absorption features are evident at ~ 19 and ~ 39 keV. Correcting for the gravitational redshift of a ~ 1.4 solar mass neutron star, the inferred surface magnetic field strength is B = 2.1 10E12 G that is typical for this kind of systems. We also detected an iron emission line at ~ 6.4 keV, with an equivalent width of ~ 60 eV.
Cite
@article{arxiv.astro-ph/9809167,
title = {Detection of a cyclotron line and its second harmonic in 4U1907+09},
author = {G. Cusumano and T. Di Salvo and L. Burderi and M. Orlandini and S. Piraino and N. Robba and A. Santangelo},
journal= {arXiv preprint arXiv:astro-ph/9809167},
year = {2008}
}
Comments
4 pages, 3 postscript figures. Accepted for publication in Astronomy and Astrophysics