XMM-Newton study of the persistent X-ray source 1E 1743.1-2843 located in the Galactic Center direction

Abstract

We report the results of an XMM-Newton observation of the persistent X-ray source 1E 1743.1-2843, located in the Galactic Center (GC) direction. We determine the position of the source at alpha_J2000 =17^h 46^m 21.0^s, delta_J2000 =-28^o 43' 44'' (with an uncertainty of 1.5''), which is the most accurate to date, and will enable cross-identifications at other wavelengths. The source was bright during this observation (L₂-10 keV ~ 2.7 x 10³⁶ d²₁₀ kpc erg s^-1 for a power-law continuum), with no significant variability. We propose that 1E 1743.1-2843 may be explained in terms of a black hole candidate in a low/hard state. There is an indication that the source exhibits different states from a comparison of our results with previous observations (e.g., ART-P, BeppoSAX). However, the present spectral analysis does not rule out the hypothesis of a neutron star low-mass X-ray binary as suggested previously. If 1E 1743.1-2843 is actually located in the GC region, we might expect to observe significant 6.4 keV fluorescent iron line emission from nearby molecular clouds (e.g., GCM+0.25+0.01).