Speaker
Description
Neutron star X-ray binaries exhibit complex phenomena that require multiwavelength polarimetric data to understand. Among them, Scorpius X-1 displays particularly remarkable behaviour across wavelengths. X-ray polarimetry has revealed an intricate geometry of the inner accretion region, while optical photometry has shown a bimodal flux distribution with a 12.5 h lag behind the X-ray state transitions, consistent with thermal reprocessing within the disk. This suggests that the optical emission traces changes in the inner flow, yet no time-resolved optical polarimetry has tested this link. We conducted a high-precision polarimetric campaign using the DIPol-UF instrument at the Nordic Optical Telescope and the DIPol-2 instrument at the T60 telescope to better constrain the geometry of the system and track the evolution of the polarization degree and angle across optical state changes. Here, we present the results of this campaign and discuss its implications.