The Burst Spectra of EXO 0748-676 during a Long 2003 XMM-Newton Observation

Understand

Gravitationally redshifted absorption lines from highly ionized iron have been previously identified in the burst spectra of the neutron star in EXO 0748-676.

• To repeat this detection we obtained a long, nearly 600 ks observation of the source with XMM-Newton in 2003.
• The spectral features seen in the burst spectra from the initial data are not reproduced in the burst spectra from this new data.
• In this paper we present the spectra from the 2003 observations and discuss the sensitivity of the absorption structure to changes in the photospheric conditions.