2024/05/14 by Linhua Jiang, Shuqi Fu, Jiang, Linhua +17 · 1 citation
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy and Astrophysical Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2405.08977
openalex publication_date 2024/05/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
We present constraints on the spacetime variation of the fine-structure constant α at redshifts 2.5≤ z<9.5 using JWST emission-line galaxies. The galaxy sample consists of 621 high-quality spectra with strong and narrow [O III] λλ4959,5007 doublet emission lines from 578 galaxies, including 232 spectra at z>5. The [O III] doublet lines are arguably the best emission lines to probe the variation in α. We divide our sample into six subsamples based on redshift and calculate the relative variation Δα/α for the individual subsamples. The calculated Δα/α values are consistent with zero within 1σ at all redshifts, suggesting no time variation in α above a level of (1-2) ×10-4 (1σ) in the past 13.2 billion years. When the whole sample is combined, the constraint is improved to be Δα/α= (0.2±0.7) ×10-4. We further test the spatial variation in α using four subsamples of galaxies in four different directions on the sky. The measured Δα/α values are consistent with zero at a 1σ level of ∼ 2×10-4. While the constraints in this work are not as stringent as those from lower-redshift quasar absorption lines in previous studies, this work uses an independent tracer and provides the first constraints on Δα/α at the highest redshifts. With the growing number of emission-line galaxies from JWST, we expect to achieve stronger constraints in the future.