Determine the origin of the northern SO emission structure

Determine the origin of the northern SO 6₅–5₄ emission structure located approximately 0.3 arcsec north of IRAM 04191+1522, including whether it is a gravitationally bound structure or an accretion streamer.

Background

The ALMA SO 6₅–5₄ observations reveal a compact structure north of IRAM 04191+1522. Its projected extent is approximately 0.3 arcsec, corresponding to about 42 au at the adopted distance of 140 pc. The position–velocity diagram suggests that the material may be gravitationally bound, but the observations do not establish its physical nature.

The authors note that higher spectral-resolution observations at intermediate spatial scales, particularly in streamer-tracing lines such as HCO⁺, are required to determine whether the structure is an accretion streamer. Resolving this issue could clarify whether the system’s proposed episodic accretion events are linked to incoming material and could help constrain the object’s evolutionary fate.

References

In general, it is not clear whether any of these alternative scenarios can explain the spatial coincidence of the SO emission, GoHam~b over-density, millimeter continuum asymmetry, and gap in the small-grain dust distribution.

— The ALMA View of the Edge-on Gomez's Hamburger System: A Highly-Dynamic, Asymmetric Protoplanetary Disk Reveals the Earliest Phases of Giant Planet Formation  (2609.09290 - Law et al., 8 Sep 2026) in Section 4.3, “SO as a Tracer for Fragment-Driven Heating”

The origin of this structure is unclear and warrants further investigation.

— Complex morphology and kinematics at the heart of the very low luminosity object IRAM 04191+1522  (2608.17593 - Otten et al., 18 Aug 2026) in Section 4, subsection “The fate of IRAM04191”; Section 5, concluding discussion