Located in the Small Magellanic Cloud ( SMC ) , SXP214 is an X-ray pulsar in a high mass X-ray binary system with a Be-star companion .
A recent survey of the SMC under a Chandra X-ray Visionary program found the source in a transition when the X-ray flux was on a steady rise .
The Lomb-Scargle periodogram revealed a pulse period of 211.49 \pm 0.42 s , which is significantly ( > 5 \sigma ) shorter than the previous measurements with XMM-Newton and RXTE .
This implies that the system has gone through sudden spin-up episodes recently .
The pulse profile shows a sharp eclipse-like feature with a modulation amplitude of > 95 % .
The linear rise of the observed X-ray luminosity from \lesssim 2 \times to { 7 } \times { 10 } ^ { 35 } erg s { } ^ { -1 } is correlated with steady softening of the X-ray spectrum , which can be described by the changes in the local absorption from N { } _ { H } \sim 10 { } ^ { 24 } to \lesssim 10 { } ^ { 20 } cm { } ^ { -2 } for an absorbed power-law model .
The soft X-ray emission below 2 keV was absent in the early part of the observation when only the pulsating hard X-ray component was observed , whereas at later times both soft and hard X-ray components were observed pulsating .
A likely explanation is that the neutron star was initially hidden in the circumstellar disk of the companion , and later came out of the disk with the accreted material that continued fueling the observed pulsation .