We unveil the stellar wind driven shell of the luminous massive star-forming region of RCW 49 using SOFIA FEEDBACK observations of the [CII] 158 μm line. The complementary dataset of the 12CO and 13CO J = 3 - 2 transitions is observed by the APEX telescope and probes the dense gas toward RCW 49. Using the spatial and spectral resolution provided by the SOFIA and APEX telescopes, we disentangle the shell from a complex set of individual components of gas centered around RCW 49. We find that the shell of radius ~ 6 pc is expanding at a velocity of 13 km s−1 toward the observer. Comparing our observed data with the ancillary data at X-Ray, infrared, sub-millimeter and radio wavelengths, we investigate the morphology of the region. The shell has a well defined eastern arc, while the western side is blown open and is venting plasma further into the west. Though the stellar cluster, which is ~ 2 Myr old gave rise to the shell, it only gained momentum relatively recently as we calculate the shell's expansion lifetime ~ 0.27 Myr, making the Wolf-Rayet star WR20a a likely candidate responsible for the shell's re-acceleration.
@article{arxiv.2104.04276,
title = {SOFIA FEEDBACK survey: exploring the dynamics of the stellar wind driven shell of RCW 49},
author = {M. Tiwari and R. Karim and M. W. Pound and M. Wolfire and A. Jacob and C. Buchbender and R. Güsten and C. Guevara and R. D. Higgins and S. Kabanovic and C. Pabst and O. Ricken and N. Schneider and R. Simon and J. Stutzki and A. G. G. M. Tielens},
journal= {arXiv preprint arXiv:2104.04276},
year = {2021}
}