The first results of observations of the transient pulsar SAX J2103.5+4545 by the INTEGRAL Observatory

We present the preliminary results of our analysis of the observations of the X-ray pulsar SAX J2103.5+4545 by the INTEGRAL Observatory in December 2002. We mapped this region of the sky in a wide energy range, from 3 to 200 keV. The detection of the source is shown to be significant up to energies of similar to100 keV The hard X-ray flux in the energy range 15-100 keV is variable and presumably depends on the orbital phase. We show that the shape of the pulsar spectrum and its parameters derived from 18-150-keV IBIS data are compatible with the RXTE observations of the source. (C) 2003 MAIK Nauka/Interperiodica.