Oral Presentation
Investigating the connection between spatially-extended, narrow line-width SiO emission and accretion shocks onto molecular clouds?
Presenter: Seamus Clarke (NCKU)
Star formation is reliant on the assembly of gas into dense structures which may become gravitationally unstable. This process is controlled by accretion flows gathering diffuse material from larger-scales into dense filaments and cores. These accretion flows are thought to be accompanied by accretion shocks which themselves can be traced by certain molecules such as SiO. Recently, spatially-extended, low line-width SiO emission has been found in clouds which is interpreted as the presence of large-scale, low-velocity accretion shocks; however, this interpretation is not settled. Band 1 provides access to the SiO (1-0) line at 43.4 GHz and is thus an excellent means to test this interpretation for the cold, dense gas in molecular clouds. In this talk, we will present single dish Q-band observations of the SiO (1-0) line taken using the Yebes 40m telescope of the giant molecular filament G214.5-1.8 which shows a unique, strong, extended accretion flow signature. This makes G214.5-1.8 an ideal target to study the connection between spatially-extended, narrow line-width SiO emission and accretion flows. These data are compared to multi-J CO and NH3 single-dish data, allowing connections with the larger-scale flows and dense gas kinematics, as well as band 3 ALMA N2H+ and HNC data, highlighting the need for high resolution SiO (1-0) observations only possible with ALMA's band 1.
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