Continuity of accretion from clumps to Class 0 high-mass protostars in SDC335

This is an open access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Context. The infrared dark cloud (IRDC) SDC335.579-0.292 (hereafter, SDC335) is a massive (similar to 5000 M-circle dot) star-forming cloud which has been found to be globally collapsing towards one of the most massive star forming cores in the Galaxy, which is located at its centre. SDC335 is known to host three high-mass protostellar objects at early stages of their evolution and archival ALMA Cycle 0 data (at similar to 5 resolution) indicate the presence of at least one molecular outflow in the region detected in HNC. Observations of molecular outflows from massive protostellar objects allow us to estimate the accretion rates of the protostars as well as to assess the disruptive impact that stars have on their natal clouds during their formation.Aims. The aim of this work is to identify and analyse the properties of the protostellar-driven molecular outflows within SDC335 and use these outflows to help refine the properties of the young massive protostars in this cloud.Methods. We imaged the molecular outflows in SDC335 using new data from the Australia Telescope Compact Array of SiO and Class I CH3OH maser emission (at a resolution of similar to 3 '') alongside observations of four CO transitions made with the Atacama Pathfinder EXperiment and archival Atacama Large Millimeter/submillimeter Array (ALMA) CO, (CO)-C-13 (similar to 1 ''), and HNC data. We introduced a generalised argument to constrain outflow inclination angles based on observed outflow properties. We then used the properties of each outflow to infer the accretion rates on the protostellar sources driving them. These accretion properties allowed us to deduce the evolutionary characteristics of the sources. Shock-tracing SiO emission and CH3OH Class I maser emission allowed us to locate regions of interaction between the outflows and material infalling to the central region via the filamentary arms of SDC335.Results. We identify three molecular outflows in SDC335 - one associated with each of the known compact HII regions in the IRDC. These outflows have velocity ranges of similar to 10 km s(-1) and temperatures of similar to 60 K. The two most massive sources (separated by similar to 9000 AU) have outflows with axes which are, in projection, perpendicular. A well-collimated jet-like structure with a velocity gradient of similar to 155 km s(-1) pc(-1) is detected in the lobes of one of the outflows. The outflow properties show that the SDC335 protostars are in the early stages (Class 0) of their evolution, with the potential to form stars in excess of 50 M-circle dot. The measured total accretion rate, inferred from the outflows, onto the protostars is 1.4(+/- 0.1) x 10(-3) M-circle dot yr(-1), which is comparable to the total mass infall rate toward the cloud centre on parsec scales of 2.5(+/- 1.0) x 10(-3) M-circle dot yr(-1), suggesting a near-continuous flow of material from cloud to core scales. Finally, we identify multiple regions where the outflows interact with the infalling material in the cloud's six filamentary arms, creating shocked regions and pumping Class I methanol maser emission. These regions provide useful case studies for future investigations of the disruptive effect of young massive stars on their natal clouds.© A. Avison et al. 2021.The Australia Telescope Compact Array is part of the Australia Telescope which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. The authors would like to thank all ATNF staff past and present who helped during the ATCA observation used in this paper, particularly those who provided A.A. with curry. The authors would also like to thank the anonymous referee for their input into the paper after initial submission which has helped to improve the work. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00474.S and #2012.0.00781.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This publication is based on data acquired with the Atacama Pathfinder EXperiment (APEX). APEX is a collaboration between the Max-Planck-Institut fuer Radioastronomie, the European Southern Observatory, and the Onsala Space Observatory. A.A. is funded by the STFC at the UK ARC Node. G.A.F acknowledges financial support from the State Agency for Research of the Spanish MCIU through the AYA2017-84390-C2-1-R grant (co-funded by FEDER) and through the "Center of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). N.P. wishes to acknowledge support under STFC consolidated grants ST/N000706/1 and ST/S00033X/1. A.D.C acknowledges the support from the UK STFC consolidated grant ST/N000706/1. A.L.R acknowledges support from NASA through Einstein Postdoctoral Fellowship grant number PF7-180166 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. This research made use of APLpy, an open-source plotting package for Python hosted at http://aplpy.github.com.This research made use of Astropy (http://www.astropy.org), a community-developed core Python package for Astronomy (Astropy Collaboration 2013, 2018).Peer reviewe