MG12 - Talk detail |
Participant |
Suleimanov, Valery | |
Institution |
Institute for Astronomy and Astrophysics - Sand 1 - Tuebingen - - Germany | |
Session |
Talk |
Abstract |
APT2 |
Absorption features in the spectra of X-ray bursting neutron stars |
Spectral analysis using model-atmosphere techniques is an adequate tool to determine photospheric parameters of neutron stars. Our aim is to identify iron lines in the X-ray spectra of individual neutron stars with low magnetic fields and check the observational results reported early by Cottam et al.(2002). We shown that absorption lines of FeXXIV -- FeXXVI ions dominate at wavelengths 8 - 14 \AA and at Teff 5 -- 12 MK. The absorption lines within this band very weak at higher temperatures. The identification of FeXXV and FeXXVI absorption lines formed at the stellar surface of EXO\,0748-676 cannot be verified, neither by NLTE nor by LTE model-atmosphere spectra. If real, they stem rather from FeXXIV at z = 0.24. |