Angular Momentum Modulation in Inner Protoplanetary Disks

Determine how the inner protoplanetary disk around young stellar objects distributes and modulates angular momentum across timescales from hours to years, using spectrally and temporally resolved diagnostics to characterize mass transport and magnetospheric coupling at sub-au scales.

Background

The paper emphasizes that key dynamical processes at the star–disk interface are inherently time-variable and require high-cadence spectroscopy to resolve. Multi-resolution MOS/IFS observations of lines such as H I, He I, Ca II, [O I], [S II], and CO rovibrational bands can decompose multi-component profiles and trace magnetospheric funnel flows, accretion shocks, disk winds, and turbulence in the hot inner disk on timescales from minutes to years.

References

Here are the major open questions that the next big telescope developed by ESO will address through conducting a decadal spectroscopic survey of YSOs: How does the inner disk distribute and modulate angular momentum on timescales from hours to years?

— Toward the time-domain spectroscopic study of the dynamic life of stars: from accretion to magnetic activity  (2512.12453 - Majidi et al., 13 Dec 2025) in Key Questions