Spectral consequences of massive-star tidal disruptions (ANTs vs. classical TDEs)

Determine why tidal disruptions of massive stars by supermassive black holes would produce optical spectra that are distinct from those of classical tidal disruption events, especially in the context of ambiguous nuclear transients that have been speculated to arise from such massive-star disruptions.

Background

The paper discusses ambiguous nuclear transients (ANTs), a class of luminous nuclear events with spectra that do not resemble supernovae, classical tidal disruption events (TDEs), or normal active galactic nuclei. ANTs have been speculated to result from tidal disruptions of massive stars, far beyond typical solar-mass stars implicated in classical optical TDEs.

Despite this speculation, the authors point out an unresolved issue: if ANTs are indeed massive-star TDEs, it remains unclear why their optical spectra differ markedly from those of classical TDEs, which typically show broad hydrogen and/or helium emission lines. Clarifying the physical mechanisms (e.g., radiative transfer, outflow properties, environmental effects) that lead to distinct spectral signatures is a key open question.