On the spin modulated circular polarization from the intermediate polars NY Lup and IGRJ1509-6649

Abstract

We report on high time resolution, high signal/noise, photo-polarimetry of the intermediate polars NY Lup and IGRJ1509-6649. Our observations confirm the detection and colour dependence of circular polarization from NY Lup and additionally show a clear white dwarf, spin modulated signal. From our new high signal/noise photometry we have unambiguously detected wavelength dependent spin and beat periods and harmonics thereof. IGRJ1509-6649 is discovered to also have a particularly strong spin modulated circularly polarized signal. It appears double peaked through the I filter and single peaked through the B filter, consistent with cyclotron emission from a white dwarf with a relatively strong magnetic field. We discuss the implied accretion geometries in these two systems and any bearing this may have on the possible relationship with the connection between polars and soft X-ray-emitting IPs. The relatively strong magnetic fields is also suggestive of them being polar progenitors.

8 pages, 6 figures and 1 table. Accepted for publication in MNRAS

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Cited by in corpus (9)

• Magnetic White Dwarfs
• Polarimetric evidence of a white dwarf pulsar in the binary system AR Scorpii
• Characterization of new hard X-ray Cataclysmic Variables
• VLA Radio Observations of AR Sco
• Measuring the masses of Intermediate Polars with NuSTAR: V709 Cas, NY Lup and V1223 Sgr
• Steps towards a solution of the FS Aurigae puzzle. II. Confirmation of the intermediate polar status
• Search for magnetic accretion in SW Sextantis systems
• Unravelling optical and X-ray properties of the disc-dominated intermediate polar IGR J15094-6649
• Constraints on the magnetic field structure in accreting compact objects from aperiodic variability