Portal de Periódicos da CAPES

MOPTOP: a multi-colour optimised optical polarimeter

2016; SPIE; Volume: 9908; Linguagem: Inglês

10.1117/12.2232324

1996-756X

Helen Jermak, I. A. Steele, R. J. Smith,

Neutrino Physics Research

We present the design and science case for the Liverpool Telescope's fourth-generation polarimeter; MOPTOP: a Multicolour OPTimised Optical Polarimeter which is optimised for sensitivity and bi-colour observations. We introduce an optimised polarimeter which is as far as possible limited only by the photon counting efficiency of the detectors. Using a combination of CMOS cameras, a continuously rotating half-wave plate and a wire grid polarising beamsplitter, we predict we can accurately measure the polarisation of sources to ~ 1% at ~19th magnitude in 10 minutes on a 2 metre telescope. For brighter sources we anticipate much low systematics (⪅ 0.1%) than our current polarimeter. The design also gives the ability to measure polarization and photometric variability on timescales as short as a few seconds. Overall the instrument will allow accurate measurements of the intra-nightly variability of the polarisation of sources such as gamma-ray bursts and blazars (AGN orientated with the jet pointing toward the observer), allowing the constraint of magnetic field models revealing more information about the formation, ejection and collimation of jets.