We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2 ( STO2 ) .
The Trumpler 14/Carina I region is in the west part of the Carina Nebula Complex , which is one of the most extreme star-forming regions in the Milky Way .
We observed Trumpler 14/Carina I in the 158 \mu m transition of [ C ii ] with a spatial resolution of 48 ^ { \prime \prime } and a velocity resolution of 0.17 km s ^ { -1 } .
The observations cover a 0.25 ^ { \circ } by 0.28 ^ { \circ } area with central position l = 297.34 ^ { \circ } , b = -0.60 ^ { \circ } .
The kinematics show that bright [ C ii ] structures are spatially and spectrally correlated with the surfaces of CO clouds , tracing the photodissociation region and ionization front of each molecular cloud .
Along 7 lines of sight that traverse Tr 14 into the dark ridge to the southwest , we find that the [ C ii ] luminosity from the HII region is 3.7 times that from the PDR .
In same los we find in the PDRs an average ratio of 1:4.1:5.6 for the mass in atomic gas : dark-CO gas : molecular gas traced by CO .
Comparing multiple gas tracers including HI 21cm , [ C ii ] , CO , and radio recombination lines , we find that the HII regions of the Carina Nebula Complex are well-described as HII regions with one-side freely expanding towards us , consistent with the champagne model of ionized gas evolution .
The dispersal of the GMC in this region is dominated by EUV photoevaporation ; the dispersal timescale is 20-30 Myr .