PhysicsarXiv
Heuristic editor, no API keyVerdict: NotableExtreme MgII Emission in Recently-Quenched Galaxies: A New Sample of Intermediate-Redshift Post-Starburst Quasars from the DESI Early Data Release
Post-starburst galaxies are galaxies which have recently and rapidly shut off star formation.
Key numbers
- 3 x 10 41 erg
- 1.2 % of the post-starburst parent
- 2.8 % of post-starbursts in the
VerdictWorth a reader's time today.
Abstract
Post-starburst galaxies are galaxies which have recently and rapidly shut off star formation. AGN activity is often invoked to explain this rapid quenching, but most post-starburst selection methods select against optical AGN, motivating searches for "post-starburst quasars." We present DESI observations of ten post-starburst quasars with significant MgII emission (L_MgII ≥ 3 × 10⁴¹ erg/s). This is the first sample of post-starburst quasars to be selected from a post-starburst galaxy parent sample rather than a quasar catalog. Quasars make up 4.6⁺1.6_-1.2% of the post-starburst parent sample at 0.49 ≤ z ≤ 1.39. Using multiwavelength AGN diagnostics, we find that 26⁺3.0_-2.8% of post-starbursts in the parent sample host AGN. We find that post-starburst selection methods are biased against AGN with L_Bolgtrsim10⁴⁵ erg s⁻¹, potentially removing the quasars responsible for driving outflows that aid in quenching. Finally, we find that 9/10 post-starburst quasars in our sample have no detected broad H$β$, similar to so-called "MgII emitters" that may be the remnants of fading quasars; if confirmed, these objects suggest a link between post-starburst galaxies and variable AGN. Our new sample of post-starburst quasars provides a link between previously reported local and high redshift post-starburst quasars during the epoch when star formation throughout the universe was declining.
The editor's rubric
| Dimension | Level | Weight | What that level means |
|---|---|---|---|
| Leverage | ███░░ 3 | 18% | A method or resource many groups across the field will adopt within a year. |
| Magnitude | ██░░░ 2 | 20% | Solid incremental gain on a meaningful problem. |
| Evidence | ███░░ 3 | 22% | Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data. |
| Novelty | ███░░ 3 | 22% | A genuinely new approach to an open problem. |
| Trajectory | ██░░░ 2 | 10% | Some room to improve with obvious engineering. |
| Stakes | ██░░░ 2 | 8% | Benefits a professional community (practitioners, clinicians, engineers). |
Editor’s rationale
Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we propose, we report, named contribution); novelty (alternative to status quo); verification (independent replication, code released); stakes (climate).
How the score was computed
- Merit
- 5.2 / 10
- Adjusted merit
- 4.5 / 10
- Attention
- 0%
- Freshness
- 83%
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