Measure the outflow velocity

Determine the outflow velocity of the ionised absorber in 2MASS J14302580+4159572 by obtaining data with sufficient spectral quality to identify its ionised absorption features, thereby replacing the current escape-velocity assumption with an observational constraint.

Background

The authors interpret the transient absorber as potentially arising from an outflow, but the available XMM-Newton EPIC spectra lack the resolution and signal-to-noise needed to detect individual absorption features. The RGS data are also insufficient for this purpose.

Because the outflow velocity is not measured, the analysis assumes that it equals the escape velocity at the inferred launch radius, treating this as a meaningful lower bound. Directly constraining the velocity would improve estimates of the outflow distance, density, energetics, and physical origin.

References

On the other hand the outflow velocity remains unconstrained. The limited EPIC spectral quality and the lack of sufficient signal-to-noise ratio RGS data do not allow the identification of ionised absorption spectral features and the estimation of the outflow velocity.

— The rise and decline of a transient obscuration event in a moderately distant type-I quasar  (2609.19910 - Akylas et al., 17 Sep 2026) in Section 8, subsection “Outflow scenario”