Contributed Talk - Splinter ISM

Wednesday, 23 September 2020, 14:39   (virtual room F)

Dealing with large data sets: an application of automated techniques to study real and synthetic obs

Seamus Clarke, Stefanie Walch, Alvaro Sanchez-Monge, Gwenllian Williams
University of Cologne, University of Hertfordshire

Observations in the far-infrared and the submillimetre have revealed that filamentary structures are prevalent on multiple scales in the interstellar medium. Moreover, surveys of molecular clouds show that star-forming cores are intimately linked to these filaments, residing along the filaments or at junctions of multiple filaments. It is thus imperative to study these structures if we wish to gain a better understanding of star formation. The recent Hi-GAL catalogue of filamentary structures in the galactic plane identified over 30,000 filaments. This highlights an increasingly pressing problem in astronomy, that of larger and larger data sets. Our current techniques require considerable human interaction and as such are too time-consuming when applied to current large volume data sets. Here we present a pipeline which contains a series of automated techniques for the analysis of filaments, including spine and core identification; filament width, line-mass and core mass estimation; spectral fitting and velocity gradient detection. It is only with these automated techniques that we are able to make use of the large data sets we currently possess, and the yet larger ones to come. Furthermore, by using the same techniques on synthetic observations as those used on real observations a robust comparison can be made and a bridge built between observations and theory. As such, we show the application of these techniques to synthetic observations of a simulated filament, as well as to real observations of a giant molecular filament, G214.5-1.8. Using these techniques we show that simulations suggest that cores forming at the junctions of multiple filaments are more massive than those formed along individual filaments, and are associated with multiple velocity components and large line-widths. From the observations, we show we have found the narrowest and coldest giant molecular filament currently known. Moreover, the filament harbours numerous massive cores but shows no sign of current high-mass star formation.