An 600 pc View of the Strongly Lensed, Massive Main-sequence Galaxy J0901: A Baryon-dominated, Thick Turbulent Rotating Disk with a Clumpy Cold Gas Ring at z=2.259

We present a high-resolution kinematic study of the massive main-sequence star-forming galaxy (SFG) SDSS J090122.37+181432.3 (J0901) at z = 2.259, using similar to 0 ''.36 Atacama Large Millimeter/submillimeter Array CO(3-2) and similar to 0 ''.1-0 ''.5 SINFONI/VLT H alpha observations. J0901 is a rare, strongly lensed but otherwise normal massive (log (M-star/M-circle dot) similar to 11) main-sequence SFG, offering a unique opportunity to study a typical massive SFG under the microscope of lensing. Through forward dynamical modeling incorporating lensing deflection, we fit the CO and Ha kinematics in the image plane out to about one disk effective radius (Re similar to 4 kpc) at an similar to 600 pc delensed physical resolution along the kinematic major axis. Our results show high intrinsic dispersions of the cold molecular and warm ionized gas (sigma(0,mol). similar to 40 km s(-1) and sigma(0,ion.) similar to 66 km s(-1)) that remain constant out to Re; a moderately low dark matter fraction (fDM similar to 0.3-0.4) within Re; and a centrally peaked Toomre Q parameter-agreeing well with the previously established sigma(r)0 versus z, f(DM) versus Sigma(baryon), and Q's radial trends using large-sample non-lensed main-sequence SFGs. Our data further reveal a high stellar mass concentration within similar to 1-2 kpc with little molecular gas, and a clumpy molecular gas ring-like structure at R similar to 2-4 kpc, in line with the inside-out quenching scenario. Our further analysis indicates that J0901 had assembled half of its stellar mass only similar to 400 Myr before its observed cosmic time, and the cold gas ring and dense central stellar component are consistent with signposts of a recent wet compaction event of a highly turbulent disk found in recent simulations.