ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions – IX. A pilot study towards IRDC G034.43+00.24 on multi-scale structures and gas kinematics

Outflow and Infall in a Sample of Massive Star Forming Regions II: Large Scale Kinematics

We present maps of seven sources selected from Klaassen & Wilson (2007a) in SiO (J=8-7) and HCO and HCO (J=4-3) which were obtained using HARPB on the James Clerk Maxwell Telescope. We find that four out of our seven sources have infall signatures based on their HCO emission profiles. From our maps, we have determined the extent of both the outflowing and infalling regions towards these sources...

Magnetic Fields in Massive Star Forming Regions

We present the largest sample of high-mass star-forming regions observed using submillimetre imaging polarimetry. The data were taken using SCUBA in conjunction with the polarimeter on the JCMT in Hawaii. In total, 16 star forming regions were observed, although some of these contain multiple cores. The polarimetry implies a variety of magnetic field morphologies, with some very ordered fields....

Observations of Infall in Star-forming Regions

Chemistry as a probe of the structures and evolution of massive star-forming regions

We present detailed thermal and gas-phase chemical models for the envelope of the massive starforming region AFGL 2591. By considering both timeand space-dependent chemistry, these models are used to study both the physical structure proposed by van der Tak et al. (1999; 2000), as well as the chemical evolution of this region. The model predictions are compared with observed abundances and colu...

A multi-transition molecular line study of inward motions towards massive star-forming cores

Amulti-transition 3mmmolecular line single-pointing and mapping survey was carried out towards 29 massive star-forming cores in order to search for the signature of inward motions. Up to seven different transitions, optically thick lines HCO(1-0), CS(2-1), HNC(1-0), HCN(1-0), CO(1-0) and optically thin lines CO(1-0), CO(1-0) were observed towards each source. The normalized velocity differences...