Magnetic field properties as a function of density at R < 500 pc in our fiducial CHEM_MHD simulation at t = 186 Myr. Top: magnetic field strength. The В ∝ п^2/3 indicates the scaling expected from simple isotropic collapse with flux-freezing (Mestel 1965). The dotted line В ∝ n^0.33 is the fit to the average instead. Symbols denote various estimates of the magnetic field in the CMZ from the literature. References are abbreviated as follows: LaRosa et al. (2005, LRO5), Yusef-Zadeh et al. (2013, YZ13), Yusef-Zadeh et al. (2022, YZ22), Schwarz & Lasenby (1990, S&L90), Uchida & Guesten (1995, U&G95), Marshall et al. (1995, M95), Crutcher et al. (1996, C96), Yusef-Zadeh et al. (1996, YZ96), Yusef-Zadeh et al. (1999, YZ99), Mangilli et al. (2019, M19), Inoue et al. (1984,184), Tsuboi et al. (1986, T86), Yusef-Zadeh & Morris (1987, YZ&M87), Gray et al. (1995, G95), Pillai et al. (2015, P15). Middle: Alſvén velocity (Eq. (10)) and thermal sound speed c_s = γP/ρ where P is the thermal pressure (Eq. (7)). Bottom: plasma β = P/P_mag, where P_mag = B²/(8π) is the magnetic pressure. In all panels, each density slice is normalised separately for clarity of visualisation, and the solid lines show the average value at the given density.