We present results of interferometric polarization observations of the recently discovered magnetar J1745 - 2900 in the vicinity of the Galactic center .
The observations were made with the Karl G. Jansky Very Large Array ( VLA ) on 21 February 2014 in the range 40–48 GHz .
The full polarization mode and A configuration of the array were used .
The average total and linearly polarized flux density of the pulsar amounts to 2.3 \pm 0.31 mJy beam ^ { -1 } and 1.5 \pm 0.2 mJy beam ^ { -1 } , respectively .
Analysis shows a rotation measure ( RM ) of ( -67 \pm 3 ) \times 10 ^ { 3 } rad m ^ { -2 } , which is in a good agreement with previous measurements at longer wavelengths .
These high frequency observations are sensitive to RM values of up to \sim 2 \times 10 ^ { 7 } rad m ^ { -2 } .
However , application of the Faraday RM synthesis technique did not reveal other significant RM components in the pulsar emission .
This supports an external nature of a single thin Faraday-rotating screen which should be located close to the Galactic center .
The Faraday corrected intrinsic electric vector position angle is 16 \pm 9 deg East of North , and coincides with the position angle of the pulsar ’ s transverse velocity .
All measurements of the pulsar ’ s RM value to date , including the one presented here , well agree within errors , which points towards a steady nature of the Faraday-rotating medium .