Akademik Veri Yönetim Sistemi
Yildiz U. (Yürütücü)
Diğer Ülkelerdeki Kamu Kurumları Tarafından Desteklenmiş Proje, 2020 - 2026
Oxygen (O) is the third-most abundant element in the Universe after hydrogen and helium. Despite its high elemental abundance, a good picture of where oxygen is located in low-mass protostellar outflows and jets is missing: we cannot account for > 60% of the oxygen budget in these objects. This hole in our picture means that we currently do not have a good understanding of the dominant cooling processes in outflows jets, despite the fact that [O I] emission at 63 micron is one of the dominant cooling lines, nor how cooling processes evolve with protostellar evolution. To shed light on these processes, we propose to observe the [O I] 63 micron line with SOFIA-GREAT toward five high-mass protostars in small maps to specifically be able to quantify any
changes in the oxygen chemistry as a function of position, and to be able to convolve the data to the 20$''$ resolution of our H$_2$O observations with Herschel. As a first step, the velocity-resolved line profile will be decomposed into its constituent components to isolate the relative contributions from the jet and the irradiated outflow. Second, the [O I] line profile will be compared to those of H2O, OH and CO to obtain the relative atomic O abundance with respect to CO, H2O, and OH. Third, the observations will be compared to lower-mass protostars where the role of UV-radiation is smaller. These three approaches will allow us to quantify: the oxygen chemistry in warm and hot gas, the relative amounts of material in the outflow and the jet, and finally to start tracing the sequence of how feedback evolves with mass.