Sobey, C.C.SobeyBilous, A. V.A. V.BilousGrießmeier, J. -M.J. -M.GrießmeierHessels, J. W. T.J. W. T.HesselsKarastergiou, A.A.KarastergiouKeane, E. F.E. F.KeaneKondratiev, V. I.V. I.KondratievKramer, M.M.KramerMichilli, D.D.MichilliNoutsos, A.A.NoutsosPILIA, MauraMauraPILIAPolzin, E. J.E. J.PolzinStappers, B. W.B. W.StappersTan, C. M.C. M.Tanvan Leeuwen, J.J.van LeeuwenVerbiest, J. P. W.J. P. W.VerbiestWeltevrede, P.P.WeltevredeHeald, G.G.HealdAlves, M. I. R.M. I. R.AlvesCARRETTI, ETTOREETTORECARRETTIEnßlin, T.T.EnßlinHaverkorn, M.M.HaverkornIacobelli, M.M.IacobelliReich, W.W.ReichVan Eck, C.C.Van Eck2021-02-172021-02-1720190035-8711http://hdl.handle.net/20.500.12386/30446We determined Faraday rotation measures (RMs) towards 137 pulsars in the northern sky, using Low-Frequency Array (LOFAR) observations at 110-190 MHz. This low-frequency RM catalogue, the largest to date, improves the precision of existing RM measurements on average by a factor of 20 - due to the low frequency and wide bandwidth of the data, aided by the RM-synthesis method. We report RMs towards 25 pulsars for the first time. The RMs were corrected for ionospheric Faraday rotation to increase the accuracy of our catalogue to ≈0.1 rad m<SUP>-2</SUP>. The ionospheric RM correction is currently the largest contributor to the measurement uncertainty. In addition, we find that the Faraday dispersion functions towards pulsars are extremely Faraday thin - mostly less than 0.001 rad m<SUP>-2</SUP>. We use these new precise RM measurements (in combination with existing RMs, dispersion measures, and distance estimates) to estimate the scale height of the Galactic halo magnetic field: 2.0 ± 0.3 kpc for Galactic quadrants I and II above and below the Galactic plane (we also evaluate the scale height for these regions individually). Overall, our initial low-frequency catalogue provides valuable information about the 3D structure of the Galactic magnetic field.STAMPAenArticle10.1093/mnras/stz2142-s2.0-85067058586000462410300059https://academic.oup.com/mnras/article-abstract/484/3/3646/5301409?redirectedFrom=fulltext2019MNRAS.484.3646SFIS/05 - ASTRONOMIA E ASTROFISICA