Pulse-phase spectroscopy of the anomalous X-ray pulsar 1E 1048.1-5937 in a low

1E 1048.15937 is the magnetar candidate with the largest pulsed fraction, thatis observed to be anticorrelated to the source flux. At the lowest flux level,the 110 keV pulsed fraction is >90% and a soft Xray spectral component,possibly due to thermal emission from most of the magnetar surface, emerges atpulsephase minimum. This source state provides the best opportunity to studythrough phaseresolved spectroscopy both the nonthermal and thermal emissionfrom regions of the magnetar surface at different temperatures. Since the onlyavailable observation of 1E 1048.15937 in this low flux state is a 5 ksXMMNewton observation, we propose a deeper 80 ks observation, to be performedin case the 210 keV flux falls below 4E12 erg cm2 s1. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]