Hill, A. S.A. S.HillLandecker, T. L.T. L.LandeckerCARRETTI, ETTOREETTORECARRETTIDouglas, K.K.DouglasSun, X. H.X. H.SunGaensler, B. M.B. M.GaenslerMao, S. A.S. A.MaoMcClure-Griffiths, N. M.N. M.McClure-GriffithsReich, W.W.ReichWolleben, M.M.WollebenDickey, J. M.J. M.DickeyGray, A. D.A. D.GrayHaverkorn, M.M.HaverkornLeahy, J. P.J. P.LeahySchnitzeler, D. H. F. M.D. H. F. M.Schnitzeler2020-12-032020-12-0320170035-8711http://hdl.handle.net/20.500.12386/28638The Fan Region is one of the dominant features in the polarized radio sky, long thought to be a local (distance ≲500 pc) synchrotron feature. We present 1.3-1.8 GHz polarized radio continuum observations of the region from the Global Magneto-Ionic Medium Survey and compare them to maps of Hα and polarized radio continuum intensity from 0.408 to 353 GHz. The high-frequency (>1 GHz) and low-frequency (≲600 MHz) emissions have different morphologies, suggesting a different physical origin. Portions of the 1.5 GHz Fan Region emission are depolarized by ≈30 per cent by ionized gas structures in the Perseus Arm, indicating that this fraction of the emission originates ≳2 kpc away. We argue for the same conclusion based on the high polarization fraction at 1.5 GHz (≈40 per cent). The Fan Region is offset with respect to the Galactic plane, covering -5° ≲ b ≲ +10°; we attribute this offset to the warp in the outer Galaxy. We discuss origins of the polarized emission, including the spiral Galactic magnetic field. This idea is a plausible contributing factor although no model to date readily reproduces all of the observations. We conclude that models of the Galactic magnetic field should account for the ≳1 GHz emission from the Fan Region as a Galactic scale, not purely local, feature.STAMPAenArticle10.1093/mnras/stx3892-s2.0-85032673901000398421100064https://academic.oup.com/mnras/article/467/4/4631/29987262017MNRAS.467.4631HFIS/05 - ASTRONOMIA E ASTROFISICA