Functional forms of the pitch (top) and tilt (bottom) angles as a function of the Galactic cylindrical coordinate; ρ and z, respectively.Each line corresponds to a best-fit model. Solid, dashed, dash-dotted, and dotted lines correspond to the ASS, LSA, BSS, and QSS GMF models. Blue, green, and red correspond to the best-fits obtained while assuming the n_d model to be ED, ARM4 or ARM4⊕ED, respectively.The pitch angle is constant for the ASS, BSS, and QSS models.