Contributed Talk - Splinter Stars

Wednesday, 15 September 2021, 10:20   (virtual Stars)

OI] self-absorption effects in M17SW and MonR2

Cristian Guevara
I. Physik. Institut, University of Cologne

Using the unique capabilities of upGREAT/SOFIA, we have observed simultaneously both oxygen atomic transition, [OI] 145 and 63 um lines towards M17-SW and Mon-R2. We found that [OI] 63 um is severely affected by self-absorption effects due to its optically thick emission, compared to the optically thin [OI] 145 um. Through a multi-component Gaussian fit analysis, we separate the emission into two layers, a background layer in emission and a foreground layer in absorption. We found high column densities in emission, plus cold and high column density material in absorption, of puzzling origin, also detected previously from [CII] and [13CII] observations.