Identify the origin of ambiguous emission lines

Identify the physical origin of the emission lines in the PR Ori B spectrum whose formation mechanism remains unclear, distinguishing contributions from the accretion flow, wind, nebulosity, and other components of the binary system.

Background

PR Ori B exhibits emission in Hα, forbidden oxygen lines, the Ca II infrared triplet, and He I during both quiescence and outburst. The paper compares their strengths and profiles to assess changes in winds and accretion.

Some features cannot be assigned confidently to a particular physical component, especially because the observations may include emission from both binary members and spatially extended material. The authors explicitly identify the origin of some lines as unclear.

References

The [\ion{O}{1}] forbidden lines demonstrate the change in wind emission, while the origin of some other lines are unclear.

— The FU Ori outburst of PR Ori B  (2609.09722 - Pena et al., 9 Sep 2026) in Section 5.1, “Winds during quiescence and outburst”