LRD host galaxies show average metallicity 0.08 Z_sun with narrow stable range, challenging pristine-gas formation models while ruling out typical local AGN.
What Sets the Line Profiles in Tidal Disruption Events?
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
We investigate line formation in gas that is outflowing and optically thick to electron scattering, as may be expected following the tidal disruption of a star by a super-massive black hole. Using radiative transfer calculations, we show that the optical line profiles produced by expanding TDE outflows are most likely primarily emission features, rather than the P-Cygni profiles seen in most supernova spectra. This is a result of the high line excitation temperatures in the highly irradiated TDE gas. The outflow kinematics cause the emission peak to be blueshifted and to have an asymmetric red wing. Such features have been observed in some TDE spectra, and we propose that these may be signatures of outflows. We also show that non-coherent scattering off of hot electrons can broaden the emission lines by $\sim 10000$~km~s$^{-1}$, such that in some TDEs the line width may be set by the electron scattering optical depth rather than the gas kinematics. The scattering broadened line profiles produce distinct, wing-shaped profiles that are similar to those observed in some TDE spectra. The narrowing of the emission lines over time in these observed events may be related to a drop in density rather than a drop in line-of-sight velocity.
years
2026 3verdicts
UNVERDICTED 3representative citing papers
Radiation hydro simulations produce black hole mass and viewing angle dependent bolometric correction factors (tens to thousands) and radiative efficiencies (0.001-0.1) for super-Eddington TDE flows that alleviate the missing energy problem when applied to specific events.
LRDs require Compton-thick gas at moderate metallicity plus high accretion rates producing weak X-rays to explain their non-detection, implying they are not chemically pristine.
citing papers explorer
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The metallicities of little red dot host galaxies: LRDs are metal poor, but not pristine
LRD host galaxies show average metallicity 0.08 Z_sun with narrow stable range, challenging pristine-gas formation models while ruling out typical local AGN.
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Bolometric correction factor and radiative efficiency for the super-Eddington accretion flow in tidal disruption events
Radiation hydro simulations produce black hole mass and viewing angle dependent bolometric correction factors (tens to thousands) and radiative efficiencies (0.001-0.1) for super-Eddington TDE flows that alleviate the missing energy problem when applied to specific events.
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On the quenching of LRD X-ray emission by both Compton-thick gas and high accretion rates
LRDs require Compton-thick gas at moderate metallicity plus high accretion rates producing weak X-rays to explain their non-detection, implying they are not chemically pristine.