학술논문
CEERS: Diversity of Lyα Emitters during the Epoch of Reionization
Document Type
article
Author
Intae Jung; Steven L. Finkelstein; Pablo Arrabal Haro; Mark Dickinson; Henry C. Ferguson; Taylor A. Hutchison; Jeyhan S. Kartaltepe; Rebecca L. Larson; Raymond C. Simons; Casey Papovich; Hyunbae Park; Laura Pentericci; Jonathan R. Trump; Ricardo O. Amorín; Bren E. Backhaus; Micaela B. Bagley; Caitlin M. Casey; Yingjie Cheng; Nikko J. Cleri; M. C. Cooper; Olivia R. Cooper; Jonathan P. Gardner; Eric Gawiser; Andrea Grazian; Nimish P. Hathi; Michaela Hirschmann; Anton M. Koekemoer; Ray A. Lucas; Bahram Mobasher; Nor Pirzkal; Swara Ravindranath; Amber N. Straughn; L. Y. Aaron Yung; Alexander de la Vega
Source
The Astrophysical Journal, Vol 967, Iss 1, p 73 (2024)
Subject
Language
English
ISSN
1538-4357
Abstract
We analyze rest-frame ultraviolet to optical spectra of three z ≃ 7.47–7.75 galaxies whose Ly α emission lines were previously detected with Keck/MOSFIRE observations, using the JWST/NIRSpec observations from the Cosmic Evolution Early Release Science survey. From NIRSpec data, we confirm the systemic redshifts of these Ly α emitters, and emission-line ratio diagnostics indicate these galaxies were highly ionized and metal-poor. We investigate Ly α line properties, including the line flux, velocity offset, and spatial extent. For the one galaxy where we have both NIRSpec and MOSFIRE measurements, we find a significant offset in their flux measurements (∼1.3–5× greater in MOSFIRE) and a marginal difference in the velocity shifts. The simplest interpretation is that the Ly α emission is extended and not entirely encompassed by the NIRSpec slit. The cross-dispersion profiles in NIRSpec reveal that Ly α in one galaxy is significantly more extended than the nonresonant emission lines. We also compute the expected sizes of ionized bubbles that can be generated by the Ly α sources and discuss viable scenarios for the creation of sizable ionized bubbles (>1 physical Mpc). The source with the highest-ionization condition is possibly capable of ionizing its own bubble, while the other two do not appear to be capable of ionizing such a large region, but require additional sources of ionizing photons. Therefore, the fact that we detect Ly α from these galaxies suggests diverse scenarios for the escape of Ly α during the epoch of reionization. High-spectral-resolution spectra with JWST/NIRSpec will be extremely useful for constraining the physics of patchy reionization.