0120192

We propose to study in detail a hard X-ray emission from transient and burster Aql X-1.With a total ~300 ksec exposure in 6 observations during a full outburst (one observationwith exposure of 50.4 ksec per five days after the begining of outburst) we plan to studythe evolution of hard X-ray (IBIS and SPI energy band) spectrum. That will enable us to testthe hypothesis about anti-correlation among hard and soft (JEM-X energy band) X-rayemission and answer on the questions about the nature of the hard X-ray emission(thermal-like Comptonization versus non-thermal impulsive acceleration) and do NSsystems spectral properties compare with those of BH systems. And second task isinvestigation of X-ray bursts using timing and spectral capabilities of INTEGRAL telescopes. [truncated! Please see actual data for full text]