HH 211 is a young bipolar protostellar outflow that provides insights into the early stages of star formation. Here are the key points about HH 211 from the search results:
Molecular Emission
HH 211 is a prominent source of molecular emission, particularly molecular hydrogen (H2), which traces the outflow’s shocked molecular gas. The molecular emission dominates in this young outflow, suggesting lower shock velocities that do not fully dissociate molecules.
Outflow Structure
HH 211 exhibits a bipolar outflow structure, with jets and cavities carved out by the outflow. Hubble Space Telescope images reveal the atomic and ionized components of the outflow, traced by emission lines like Hα, [SII], [NII], and [FeII].
Young Evolutionary Stage
HH 211 is classified as a Class 0 or Class I protostellar source, representing the earliest stages of star formation. Studying young outflows like HH 211 provides insights into the ejection processes that govern the formation of stars and their associated outflows.
Shock Excitation
The molecular and atomic emission lines observed in HH 211 are excited by shocks associated with the protostellar outflow. These shock-excited lines serve as diagnostics for understanding the physical conditions and kinematics of the outflow.In summary, HH 211 is a remarkable example of a young protostellar outflow, rich in molecular emission and exhibiting a bipolar structure. Its study offers valuable insights into the early stages of star formation and the ejection processes that drive outflows.
References:
Molecular emission in regions of star formation
Antoine Gusdorf. Molecular emission in regions of star formation. Astrophysics [astro-ph]. Université
Paris Sud – Paris XI, 2008. English. ffNNT : ff. fftel-00370141f
The anatomy of the young protostellar outflow HH 211
A. Tappe, J. Forbrich, S. Martín, Y. Yuan, C. J. Lada
- April 2012
- The Astrophysical Journal 751(1):9
- April 2012
- 751(1):9
HH 211: Jets from a Forming Star
Credit: NASA, ESA, CSA, Webb; Processing: Tom Ray (DIAS Dublin)
Circular Astronomy 