RoboPol: A four-channel optical imaging polarimeter

Abstract

We present the design and performance of RoboPol, a four-channel optical polarimeter operating at the Skinakas Observatory in Crete, Greece. RoboPol is capable of measuring both relative linear Stokes parameters $q$ and $u$ (and the total intensity $I$) in one sky exposure. Though primarily used to measure the polarization of point sources in the R-band, the instrument features additional filters (B, V and I), enabling multi-wavelength imaging polarimetry over a large field of view (13.6' $\times$ 13.6'). We demonstrate the accuracy and stability of the instrument throughout its five years of operation. Best performance is achieved within the central region of the field of view and in the R band. For such measurements the systematic uncertainty is below 0.1% in fractional linear polarization, $p$ (0.05% maximum likelihood). Throughout all observing seasons the instrumental polarization varies within 0.1% in $p$ and within 1${}^{\circ }$ in polarization angle.

13 pages, 15 figures, accepted for publication in MNRAS

References in corpus (14)

• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• RoboPol: The optical polarization of gamma-ray--loud and gamma-ray--quiet blazars
• RoboPol: Connection between optical polarization plane rotations and gamma-ray flares in blazars
• Optical polarization of high-energy BL Lac objects
• The magnetic field and dust filaments in the Polaris Flare
• RoboPol: Do optical polarization rotations occur in all blazars?
• Optical EVPA rotations in blazars: testing a stochastic variability model with RoboPol data
• Linear spectropolarimetry of polarimetric standard stars with VLT/FORS2
• Simultaneous Linear and Circular Optical Polarimetry of Asteroid (4) Vesta
• Early-time polarized optical light curve of GRB 131030A
• Optical polarization variations in the blazar PKS 1749+096
• Optical linear polarization of 74 white dwarfs with the RoboPol polarimeter
• The high optical polarization in the Be/X-ray binary EXO 2030+375
• The optical counterpart to the Be/X-ray binary SAX J2239.3+6116

Cited by in corpus (2)

• Extreme Starlight Polarization in a Region with Highly Polarized Dust Emission
• The RoboPol Program: Optical Polarimetric Monitoring of Blazars