Mergers lighting the early Universe: modest star-formation enhancement without evidence for AGN or Lyα triggering

Clicks: 13
ID: 328253
2026
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This article has not been analysed, so there is no overall score — reader engagement is measured and shown alongside.
AI Quality Assessment
Not analyzed
Readership in this journal
Emerging

Ranked #1,008 of 1,327 articles by views in monthly notices of the royal astronomical society

Most read Least read

Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 1,327 in total.

Mint this article as an NFT
Not yet minted

Create a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.

5 SUSD one-off · no wallet required
Abstract
Abstract Galaxy mergers and interactions are often invoked to explain enhanced star formation, black hole growth, and mass build-up of galaxies at later cosmic times, but their effect is poorly understood at high redshift (z > 2). We use JADES data to analyse a mass-complete sample of 1968 galaxies at z = 3 − 9 with log(M⋆/M⊙) = [8, 10], identifying major merger pairs (projected separation of 5 − 100 pkpc, mass ratio ≥1/4) using a probabilistic method. To look for signatures of enhancement in multiple physical properties, we carefully build a control sample of non-pairs that are simultaneously matched in redshift, stellar mass, isolation, and environment to the pair sample. We find a moderate enhancement in specific star-formation rate (sSFR) of a factor of 1.10 ± 0.05 at separations ≲ 20 kpc in pairs compared to their matched controls. We find that the interaction-related sSFR enhancement is most apparent at longer SFR averaging timescales (50–100 Myr), whereas the enhancement is not detected on 5—10 Myr timescales, where bursty star formation might be driven by internal processes. By averaging star formation histories, we find two distinct populations: one with monotonically rising SFRs and another with an earlier peak in SFR, potentially corresponding to different interaction stages. Finally, we find no significant excess of AGN in pairs, consistent with galaxy interactions not strongly triggering black hole activity at the separations probed (>5 kpc). Similarly, we also do not detect an excess in the fraction of Lyman-α emitters in pairs, suggesting that at the probed separations, galaxy interactions are not efficient at enhancing Lyman-α photon production and escape, which may only become important at the smallest physical scales.
Reference Key
openalex_W7211987574 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors
Journal monthly notices of the royal astronomical society
Year 2026
DOI
10.1093/mnras/stag1698
URL
Keywords Keywords not found

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

No comments yet. Be the first to comment on this article.