090128

The persistent Be accreting pulsars are a sub-class of the BeXRBs characterizedby persistently low luminosity (Lx = 10^(34-35) erg/s) and long pulse period (P and amp gt 100 s). Since in these binaries the matter is accreted from the low-densitywind of the companion star these systems are a particularly interestinglaboratory to study the emission processes occuring at low accretion rates.Therefore it is very important to identify and investigate new sources of thistype. To this aim we propose to observe the Galactic Be pulsar 4U 0728-25which is a poorly studied candidate member of this class of sources. Our aim isto examine at an unprecedented sensitivity level its spectral and timingproperties and to test if the description of the other persistent pulsars is applicable also in this case. [truncated! Please see actual data for full text]