Constrain the observability timescale of the evolutionary sequence

Determine the observability timescale of CO-luminous post-starburst galaxies within the proposed evolutionary sequence from compact starbursts through CO-luminous decline to CO-undetected quiescence.

Background

The authors compare the number density, star-formation rates, morphologies, and outflow properties of CO-luminous post-starburst galaxies with those of proposed compact starburst progenitors and older CO-undetected descendants. A direct evolutionary interpretation depends not only on the similarity of these properties but also on how long each phase remains observable and selectable.

The available L sample is incomplete because of SDSS targeting limitations at approximately z = 0.5. The authors argue that future mass-complete spectroscopic and imaging surveys will be needed to measure number-density evolution and thereby constrain the duration of the decline from peak star formation into the CO-luminous post-starburst phase.

References

The consistency in number density (with the caveat that observability timescales remains a significant unknown), peak star formation rate, morphology, and outflow properties as interpreted in a direct evolutionary sequence paints a picture of the CO luminous post-starburst galaxies as the direct descendants of the compact, star forming, mid-merger young HizEA galaxies.

— SQuIGG$\vec{L}$E: Spatially resolved NIRSpec Pa$α$ reveals that the most CO-luminous, $z\sim0.7$ post-starburst galaxies exhibit falling---but still active---star formation behind optically thick dust  (2609.31307 - Setton et al., 25 Sep 2026) in Section 4.2, “Running back the clock: L at the peak of their starburst”