| Autor: |
Linhua Jiang, Zhiwei Pan, Jessica Nicole Aguilar, Steven Ahlen, Robert Blum, David Brooks, Todd Claybaugh, Axel de la Macorra, Arjun Dey, Peter Doel, Kevin Fanning, Simone Ferraro, Jaime E. Forero-Romero, Enrique Gaztañaga, Satya Gontcho A Gontcho, Gaston Gutierrez, Klaus Honscheid, Stephanie Juneau, Martin Landriau, Laurent Le Guillou, Michael Levi, Marc Manera, Ramon Miquel, John Moustakas, Eva-Maria Mueller, Andrea Muñoz-Gutiérrez, Adam Myers, Jundan Nie, Gustavo Niz, Claire Poppett, Francisco Prada, Mehdi Rezaie, Graziano Rossi, Eusebio Sanchez, Edward Schlafly, Michael Schubnell, Hee-Jong Seo, David Sprayberry, Gregory Tarlé, Benjamin Alan Weaver, Hu Zou, The DESI Collaboration |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
The Astrophysical Journal, Vol 968, Iss 2, p 120 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
1538-4357 |
| DOI: |
10.3847/1538-4357/ad47b4 |
| Popis: |
We present strong constraints on the spacetime variation of the fine-structure constant α using the Dark Energy Spectroscopic Instrument (DESI). In this pilot work, we utilize ∼110,000 galaxies with strong and narrow [O iii ] λ λ 4959, 5007 emission lines to measure the relative variation Δ α / α in space and time. The [O iii ] doublet is arguably the best choice for this purpose owing to its wide wavelength separation between the two lines and its strong emission in many galaxies. Our galaxy sample spans a redshift range of 0 < z < 0.95, covering half of all cosmic time. We divide the sample into subsamples in 10 redshift bins (Δ z = 0.1), and calculate Δ α / α for the individual subsamples. The uncertainties of the measured Δ α / α are roughly between 2 × 10 ^−6 and 2 × 10 ^−5 . We find an apparent α variation with redshift at a level of Δ α / α = (2–3) × 10 ^−5 . This is highly likely to be caused by systematics associated with wavelength calibration, since such small systematics can be caused by a wavelength distortion of 0.002–0.003 Å, which is beyond the accuracy that the current DESI data can achieve. We refine the wavelength calibration using sky lines for a small fraction of the galaxies, but this does not change our main results. We further probe the spatial variation of α in small redshift ranges, and do not find obvious, large-scale structures in the spatial distribution of Δ α / α . As DESI is ongoing, we will include more galaxies, and by improving the wavelength calibration, we expect to obtain a better constraint that is comparable to the strongest current constraint. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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