SOFIA FEEDBACK Survey: Exploring the Dynamics of the Stellar Wind–Driven Shell of RCW 49

We unveil the stellar wind driven shell of luminous massive star-forming region RCW 49 using SOFIA FEEDBACK observations [CII] 158 $\mu$m line. The complementary dataset $^{12}$CO and $^{13}$CO J = 3 - 2 transitions is observed by APEX telescope probes dense gas toward 49. Using spatial spectral resolution provided telescopes, we disentangle from a complex set individual components centered around find that radius ~ 6 pc expanding at velocity 13 km s$^{-1}$ observer. Comparing our data with ancillary X-Ray, infrared, sub-millimeter radio wavelengths, investigate morphology region. has well defined eastern arc, while western side blown open venting plasma further into west. Though cluster, which Myr old gave rise to shell, it only gained momentum relatively recently as calculate shell's expansion lifetime 0.27 Myr, making Wolf-Rayet star WR20a likely candidate responsible for re-acceleration.