SF-01-0005

Core Growth and Core Mass Function in a Sample of Filament Clouds

Yu Cheng

Filamentary structures are ubiquitously found in high-mass star forming clouds, yet how they are related to star formation remains unclear. We report ALMA Band 6 continuum toward a sample of 8 high-mass star forming filaments that cover a range of evolutionary stages. Two 12-m array configurations were employed to mosaic a rectangular field toward each region, achieving an angular resolution ~0. 6" (2700 AU at 4.5 kpc) and a continuum rms of ~0.1 mJy beam (~0.05 M? for 20 K). We identify in total 199 dense cores with getsf, with each cloud having 15 - 40 cores, and classify their star formation states via outflow or warm gas tracers. We compare getsf with another algorithm astrodendro and conclude that getsf gives more robust results in core identification and flux measurement. Gas temperatures of the cores are estimated from JVLA NH3 observations at a similar spatial resolution. The protostellar cores are statistically more massive than the prestellar cores for the relatively young sub-group of INFANT clouds, possibly indicating active accretion from filaments even after formation of protostars in the early stage of cluster formation. With this sample we derive a power-law index of ?1.10 ± 0.11 for the core mass function (CMF), and ?1.47 ± 0.26 for the prestellar CMF in the high-mass end (Mcore > 1.5 M?). We also find a trend for steeper power-law indices with cloud evolution (?0.89 ± 0.14 for the young group v.s. ?1.38 ± 0.23 for the evolved group) and discuss its implication for cluster formation.