Observing the polarisation pattern of Saturn using CARMA

TL;DR

This study presents detailed polarisation observations of Saturn and its rings at 1.3 mm wavelength using CARMA, revealing anomalies potentially caused by self-gravity wakes, and discusses instrumental limitations affecting polarisation measurements.

Contribution

First polarisation data of Saturn at millimeter wavelengths using CARMA, with analysis of ring anomalies and instrumental limitations.

Findings

Anomalous polarisation pattern observed in Saturn's rings.

Possible link between anomalies and self-gravity wakes.

Instrumental limitations set upper bounds on polarisation detection.

Abstract

We observe Saturn and its ring system at wavelengths of 1.3 mm (220 GHz) using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) interferometric array. We study the intensity and polarisation structure of the planet and present the best polarisation data of Saturn at these frequencies. Observations using CARMA E-array configuration exhibited some anomalous polarisation pattern in the rings. We provide details of our analysis and discuss the possibility of self gravity wakes in Saturn's ring system resulting in this anomaly. We observe Venus in intensity and polarisation to cross-check the levels of polarisation signal detectable by CARMA. We also discuss how limitations in CARMA instrumental accuracy for observing weakly polarised sources, project this signature as an upper bound of polarisation measurements of Saturn using CARMA.