Polarization in Soft X-ray Intermediate Polars

The evolutionary connection between polars and intermediate polars (IPs) is not yet well established. Soft X-ray IPs are good candidates for progenitors of polars, but their magnetic field strengths are poorly constrained. Only a handful of them are known to be circularly polarized and converting polarized fractions into magnetic field strengths is problematic, so it is still unclear whether they are of comparable magnetic field strength to polars or not. We have performed a polarimetric survey for a sample of Soft X-ray IPs. Results provide evidences that some IPs have comparable magnetic field strengths to some polars and can hence evolve from one to the other as their orbital period decreases and synchronism is achieved.