At the center of the Milky Way, the physical conditions of the ISM and structure formation are more complicated than those of the disk of the Galaxy. The circumnuclear disk (CND) region in the Galactic Center (GC) offers a unique laboratory to study the formation and evolution of structures as the largest and closest molecular structure to SgrA. In this study, we investigate the impact of the thermal and nonthermal processes on energy balance and structure formation in this region traced with radio recombination lines (RRLs) observations. The MeerKAT 1.3 GHz radio continuum map combined with the RRL data allows the separation of the free-free and the synchrotron radiations tracing the thermal and nonthermal processes, respectively. We use ALMA H40$\alpha$ RRL from ACES survey as a reliable thermal tracer within 5\,pc from the center. We also investigate molecular gas using the JCMT and NRO data of 12CO (J=3-2) and 12CO (J=1-0).
A tight radio--FIR correlation holds indicating that a fine balance holds between the magnetic field, cosmic rays, and gas pressures in this region. The equipartition magnetic field strength mapped at 18\arcsec ~angular resolution is on average} 1.62\,$\pm$\,0.01\,mG. In the innermost region, i.e., at $R<1.7$\,pc, the magnetic field becomes stronger while the molecular gas density decreases toward SgrA, likely, due to feedback from the super-massive black hole (SMBH).
Investigating the thermal and nonthermal energy densities as well as the mass-to-magnetic flux ratio, it is inferred that this region is subcritical. Hence, the magnetic field is one of the parameters that can help the stabilization of the molecular clouds of this region against gravitational collapse.
