Multi-scale Magnetic Fields in the Central Molecular Zone

Magnetic fields in the central molecular zone have attracted a vast of attention in recent years. To get an insight into the magnetic fields, we employ the Velocity Gradient Technique (VGT), which is rooted in the anisotropy of magnetohydrodynamic turbulence. Our analysis combines the data of molecular emission lines and H I absorption line with the observations of Planck 353 GHz and HWAC+ polarized dust emissions. We present the magnetic fields in the overall central molecular zone, the radio arc, and the arched filament, accessing multi scales from the order of 10 pc to 0.1 pc. The magnetic fields towards the central molecular zone traced by VGT are globally compatible with the polarization measurements, accounting for the contribution from the galactic foreground. This correspondence suggests that the magnetic field and turbulence are dynamically crucial in the galactic center. We show VGT's advantages in decomposing magnetic fields from different velocity components and/or different gas phases. Furthermore, we find that the magnetic fields associated with the arched filaments and the thermal components of the radio arc agree with the HAWC+ polarization. The measurement towards the non-thermal radio arc reveals the poloidal magnetic field components in the galactic center.