Doppler tomography of the transient X-ray binary Centaurus X-4 in quiescence
Doppler tomography of the transient X-ray binary Centaurus X-4 in quiescence
We present ESO-NTT low resolution spectroscopy of the neutron star X-ray transient Cen X-4 in quiescence over a complete orbital cycle. Our data reveal the presence of a K3–7 V companion which contributes to the 5600–6900 flux and orbits the neutron star with a velocity semi-amplitude of km s-1. This, …