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We present combined VLA and Green Bank Telescope images of \ammonia\inversion transitions (1,1) and (2,2) toward OMC2 and OMC3. We focus on therelatively quiescent Orion cores, which are away from the Trapezium cluster andhave no sign of massive protostars nor evolved star formation, such as IRASsource, water maser, and methanol maser. The 5\arcsec\ angular resolution and$0.6 \rm{}km\,s^{-1}$ velocity resolution of these data enable us to study thethermal and dynamic state of these cores at $\sim{}0.02 \rm{}pc$ scales,comparable to or smaller than those of the current dust continuum surveys. Wemeasure temperatures for a total of 30 cores, with average masses of $11\,\Ms$,radii of $0.039 \rm{}pc$, virial mass ratio $\bar{R_{vir}}$ = 3.9, and criticalmass ratio $\bar{R_{C}}$ = 1.5. Twelve sources contain \textit{Spitzer}protostars. The thus defined starless and protostellar subsamples have similartemperature, line width, but different masses, with an average of $7.3\,\Ms$for the former and $16\,\Ms$ for the latter. Compared to others Gould Beltdense cores, mores Orion cores have a high gravitational-to kinetic energyratio and more cores have a larger thant unity critical mass ratio. Orion densecores have velocity dispersion similar to those of cores in low-massstar-forming regions but larger masses for fiven size. Some cores appear tohave truly supercritical gravitational-to-kinetic energy ratios, even whenconsidering significant observational uncertainties: thermal and non-thermalgas mothins alone cannot prevent collapse.

Massive Quiescent Cores in Orion: Dynamical State Revealed by High-Resolution Ammonia Maps