loading page

A 3D View of Orion: I. Barnard’s Loop
  • +10
  • Michael Foley,
  • Catherine Zucker,
  • Alyssa Goodman,
  • John C. Forbes,
  • João Alves,
  • Shmuel Bialy,
  • cameren swiggum,
  • Michael Y. Grudić,
  • John Bally,
  • Juan D. Soler,
  • Josefa Großchedl,
  • Torsten Ensslin,
  • Reimar Leike
Michael Foley

Corresponding Author:[email protected]

Author Profile
Catherine Zucker
Author Profile
Alyssa Goodman
Author Profile
John C. Forbes
Author Profile
João Alves
Author Profile
Shmuel Bialy
Author Profile
cameren swiggum
Author Profile
Michael Y. Grudić
Author Profile
John Bally
Author Profile
Juan D. Soler
Author Profile
Josefa Großchedl
Author Profile
Torsten Ensslin
Author Profile
Reimar Leike
Author Profile

Abstract

Barnard’s Loop is a famous arc of H\(\alpha\) emission located in the Orion star-forming region. Here, we provide evidence of a possible formation mechanism for Barnard’s Loop and compare our results with recent work suggesting a major feedback event occurred in the region around 6 Myr ago. We present a 3D model of the large-scale Orion region, indicating coherent, radial, 3D expansion of the OBP-Near/Briceño-1 (OBP-B1) cluster in the middle of a large dust cavity. The large-scale gas in the region also appears to be expanding from a central point, originally proposed to be Orion X. OBP-B1 appears to serve as another possible center, and we evaluate whether Orion X or OBP-B1 is more likely to be the cause of the expansion. Recent 3D dust maps are used to characterize the 3D topology of the entire region, which shows Barnard’s Loop’s correspondence with a large dust cavity around the OPB-B1 cluster. The molecular clouds Orion A, Orion B, and Orion \(\lambda\) reside on the shell of this cavity. Simple estimates of gravitational effects from both stars and gas indicate that the expansion of this asymmetric cavity likely induced anisotropy in the kinematics of OBP-B1. We conclude that feedback from OBP-B1 has affected the structure of the Orion A, Orion B, and Orion \(\lambda\) molecular clouds and may have played a major role in the formation of Barnard’s Loop.