Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-06-28
Mon.Not.Roy.Astron.Soc. 329 (2002) 29
Astronomy and Astrophysics
Astrophysics
10 pages, 3 figures, accepted for publication in MNRAS with very minor changes
Scientific paper
10.1046/j.1365-8711.2002.04964.x
We present VLT low resolution spectroscopy of the neutron star X-ray transient XTE J2123-058 during its quiescent state. Our data reveal the presence of a K7V companion which contributes 77 % to the total flux at 6300 A and orbits the neutron star at K_2 = 287 +/- 12 km/s. Contrary to other soft X-ray transients (SXTs), the Halpha emission is almost exactly in antiphase with the velocity curve of the optical companion. Using the light-center technique we obtain K_1 = 140 +/- 27 km/s and hence q=K_1/K_2=M_2/M_1= 0.49 +/- 0.10. This, combined with a previous determination of the inclination angle (i=73 +/- 4) yields M_1 = 1.55 +/- 0.31 Msun and M_2 = 0.76 +/- 0.22 Msun. M_2 agrees well with the observed spectral type. Doppler tomography of the Halpha emission shows a non-symmetric accretion disc distribution mimicking that seen in SW Sex stars. Although we find a large systemic velocity of -110 +/- 8 km/s this value is consistent with the galactic rotation velocity at the position of J2123-058, and hence a halo origin. The formation scenario of J2123-058 is still unresolved.
Casares Jorge
Charles Phil A.
Dubus Guillaume
Shahbaz Tariq
Zurita Cristina
No associations
LandOfFree
VLT spectroscopy of XTE J2123-058 during quiescence does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with VLT spectroscopy of XTE J2123-058 during quiescence, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VLT spectroscopy of XTE J2123-058 during quiescence will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-123574