English

Observations of Orion Source I Disk and Outflow Interface

Astrophysics of Galaxies 2020-02-12 v1

Abstract

We imaged the continuum and molecular line emission from Orion Source I (SrcI) with up to 30 mas (12 AU) resolution at 43, 99, 223, and 340 GHz in an attempt to probe the structure and chemistry of the circumstellar disk and bipolar outflow associated with this high mass protostar. The continuum spectral index ranges from \sim2 along the midplane of the disk to \sim3 along the edges, consistent with dust that is optically thick in the midplane but becomes optically thin at the periphery. Salt (NaCl) emission is visible where the dust is optically thin; it provides a unique tracer of the velocity field within the disk. All other molecules that we have mapped - H2_2O, AlO, SiO, SiS, SO, and SO2_2 - appear to originate primarily in the bipolar outflow. The base of the outflow is corotating with the disk. SiS shows a filamentary structure that is most prominent along the edges of the outflow. The molecular distributions suggest that Si and Al released from dust grains in the disk react with oxygen derived from H2_2O to form SiO and AlO, and with SO and SO2_2 to form SiS.

Keywords

Cite

@article{arxiv.1912.08862,
  title  = {Observations of Orion Source I Disk and Outflow Interface},
  author = {Melvyn Wright and Richard Plambeck and Tomoya Hirota and Adam Ginsburg and Brett A. McGuire and John Bally and Ciriaco Goddi},
  journal= {arXiv preprint arXiv:1912.08862},
  year   = {2020}
}

Comments

Accepted in the Astrophysical Journal. 18 pages, 17 figures

R2 v1 2026-06-23T12:50:17.104Z