We present analysis of 4U 1626 - 67 , a 7.7 s pulsar in a low-mass X-ray binary system , observed with the hard X-ray detector of the Japanese X-ray satellite Suzaku in March 2006 for a net exposure of \sim 88 ks .
The source was detected at an average 10–60 keV flux of \sim 4 \times 10 ^ { -10 } erg cm ^ { -2 } s ^ { -1 } .
The phase-averaged spectrum is reproduced well by combining a negative and positive power-law times exponential cutoff ( NPEX ) model modified at \sim 37 keV by a cyclotron resonance scattering feature ( CRSF ) .
The phase-resolved analysis shows that the spectra at the bright phases are well fit by the NPEX with CRSF model .
On the other hand , the spectrum in the dim phase lacks the NPEX high-energy cutoff component , and the CRSF can be reproduced by either an emission or an absorption profile .
When fitting the dim phase spectrum with the NPEX plus Gaussian model , we find that the feature is better described in terms of an emission rather than an absorption profile .
The statistical significance of this result , evaluated by means of an F-test , is between 2.91 \times 10 ^ { -3 } and 1.53 \times 10 ^ { -5 } , taking into account the systematic errors in the background evaluation of HXD-PIN .
We find that , the emission profile is more feasible than the absorption one for comparing the physical parameters in other phases .
Therefore , we have possibly detected an emission line at the cyclotron resonance energy in the dim phase .