We present detailed spectral and timing analysis of the hard x-ray transient ( catalog IGR J16358-4726 ) using multi-satellite archival observations .
A study of the source flux time history over 6 years , suggests that lower luminosity transient outbursts can be occuring in intervals of at most 1 year .
Joint spectral fits of the higher luminosity outburst using simultaneous Chandra /ACIS and INTEGRAL /ISGRI data reveal a spectrum well described by an absorbed power law model with a high energy cut-off plus an Fe line .
We detected the 1.6 hour pulsations initially reported using Chandra /ACIS also in the INTEGRAL /ISGRI light curve and in subsequent XMM-Newton observations .
Using the INTEGRAL data we identified a spin up of 94 s ( \dot { P } = 1.6 \times 10 ^ { -4 } ) , which strongly points to a neutron star nature for ( catalog IGR J16358-4726 ) .
Assuming that the spin up is due to disc accretion , we estimate that the source magnetic field ranges between 10 ^ { 13 } \sim 10 ^ { 15 } G , depending on its distance , possibly supporting a magnetar nature for ( catalog IGR J16358-4726 ) .