TY - JOUR
T1 - Understanding the LMXB X2127+119 in M 15. II. The UV data
AU - Ioannou, Z.
AU - Van Zyl, L.
AU - Naylor, T.
AU - Charles, P. A.
AU - Margon, B.
AU - Koch-Miramond, L.
AU - Ilovaisky, S.
PY - 2003
Y1 - 2003
N2 - We present HST UV observations of the high-inclination low mass X-ray binary AC211 (X2127+119), which is located in the globular cluster M 15 (NGC 7078). We have discovered a CIV P Cygni profile in this system, which confirms the existence of an outflow from AC211. The outflow velocity as measured from the P Cygni profile is ≃ 1500 km s-1. We calculate that the mass lost through this wind is too small to support a large period derivative as favoured by Homer & Charles (1998). Using new X-ray observations we have revised the ephemeris for AC211 and we find no evidence in support of a period derivative. The UV spectrum exhibits several absorption features due to O, Si and C. The very strong HeII line at 1640 Å is not seen to modulate strongly with orbital phase, suggesting its origin lies in the outer parts of the system. In contrast, the eclipse of the UV continuum is short compared with the X-ray and optical eclipses.
AB - We present HST UV observations of the high-inclination low mass X-ray binary AC211 (X2127+119), which is located in the globular cluster M 15 (NGC 7078). We have discovered a CIV P Cygni profile in this system, which confirms the existence of an outflow from AC211. The outflow velocity as measured from the P Cygni profile is ≃ 1500 km s-1. We calculate that the mass lost through this wind is too small to support a large period derivative as favoured by Homer & Charles (1998). Using new X-ray observations we have revised the ephemeris for AC211 and we find no evidence in support of a period derivative. The UV spectrum exhibits several absorption features due to O, Si and C. The very strong HeII line at 1640 Å is not seen to modulate strongly with orbital phase, suggesting its origin lies in the outer parts of the system. In contrast, the eclipse of the UV continuum is short compared with the X-ray and optical eclipses.
KW - Accretion, accretion discs
KW - Stars: binaries: eclipsing
KW - Stars: coronae
KW - Stars: individual: X2127+119, AC211
KW - Ultraviolet: stars
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U2 - 10.1051/0004-6361:20021578
DO - 10.1051/0004-6361:20021578
M3 - Article
AN - SCOPUS:0037326234
SN - 0004-6361
VL - 399
SP - 211
EP - 218
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 1
ER -