Unveiling Luminous Ly$\alpha$ Emitters at $z\approx 6$ through JWST/NIRCam Imaging in the COSMOS Field

Abstract

We study a sample of 14 spectroscopically confirmed Ly$\alpha$ Emitters (LAEs) in the late era of reionization (at redshift $z\approx 6$) based on the JWST/NIRCam imaging dataset. These LAEs with high Ly$\alpha$ luminosity of $L$(Ly$\alpha$) $\sim 10^{42.4-43.4}$ erg s${}^{-1}$ have been covered by the (ongoing) COSMOS-Web survey (Kartaltepe et al. 2021; Casey et al. 2022) over $0.28$ deg${}^2$ in four NIRCam bands (F115W, F150W, F277W, and F444W). With JWST imaging, we determine the UV continua with $M_{\mathrm{UV}}$ ranging from $-20.5$ to $-18.5$ mag. The UV slopes have a median value of $\beta \approx -2.35$, and the steepest slope can reach $\beta <-3$. Under an excellent spatial resolution of JWST, we identify three out of the sample as potential merging/interacting systems. The 14 LAEs (and their components) are compact in morphology residing substantially below the mass-size relation of high-$z$ galaxies. We further investigate the stellar mass ($M_{\ast }$) and star-formation rates (SFRs). Most of the LAEs lie on the SFR-$M_{\ast }$ main-sequence relation while two of them featured as "little red dots" likely host active galactic nuclei (AGN), implying a $\sim 10\%$ AGN fraction. Moreover, we reveal that a new correlation may exist between Ly$\alpha$ equivalent width and the offset between Ly$\alpha$ and UV emission ($\Delta d_{\mathrm{Ly}\alpha }$) with a median $\Delta d_{\mathrm{Ly}\alpha }\sim 1$ kpc. This could be explained by Ly$\alpha$ radiative transfer process in both ISM and CGM. The results usher a new era of detailed analysis on high-$z$ LAEs with the JWST capability.

arXiv comment15 pages, 5 figures, accepted by ApJL

References in corpus (73)

• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Detailed Structural Decomposition of Galaxy Images
• The James Webb Space Telescope
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• Inferring the star-formation histories of massive quiescent galaxies with BAGPIPES: Evidence for multiple quenching mechanisms
• The merger rate of galaxies in the Illustris Simulation: a comparison with observations and semi-empirical models
• The Evolution of the Star-forming Interstellar Medium across Cosmic Time
• The Science Performance of JWST as Characterized in Commissioning
• The evolution of the galaxy UV luminosity function at redshifts z ~ 8-15 from deep JWST and ground-based near-infrared imaging
• The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field
• UV-Continuum Slopes of >4000 z~4-8 Galaxies from the HUDF/XDF, HUDF09, ERS, CANDELS-South, and CANDELS-North Fields
• Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15
• The Most Luminous z~9-10 Galaxy Candidates yet Found: The Luminosity Function, Cosmic Star-Formation Rate, and the First Mass Density Estimate at 500 Myr
• CANDELS: The Evolution of Galaxy Rest-Frame Ultraviolet Colors from z = 8 to 4
• Lyman Alpha Emitting Galaxies as a Probe of Reionization
• The Spectral Energy Distributions Of z~8 Galaxies From The IRAC Ultra Deep Fields: Emission Lines, Stellar Masses, And Specific Star Formation Rates At 650 Myr
• The evolution of the dust and gas content in galaxies
• The GLASS James Webb Space Telescope Early Release Science Program. I. Survey Design and Release Plans
• Discovery and properties of ultra-high redshift galaxies ($9<z<12$) in the JWST ERO SMACS 0723 Field
• The dust content of galaxies from z = 0 to z = 9
• The ALPINE-ALMA [CII] Survey: data processing, catalogs, and statistical source properties
• Completing the Census of Ly-alpha Emitters at the Reionization Epoch
• The z = 9-10 galaxy population in the Hubble Frontier Fields and CLASH surveys: The z=9 LF and further evidence for a smooth decline in UV luminosity at z >= 8
• Great Optically Luminous Dropout Research Using Subaru HSC (GOLDRUSH). I. UV Luminosity Functions at $z\sim 4-7$ Derived with the Half-Million Dropouts on the 100 deg${}^2$ Sky
• An Atlas of z=5.7 and z=6.5 Ly alpha Emitters
• An Intensely Star-Forming Galaxy at z~7 with Low Dust and Metal Content Revealed by Deep ALMA and HST Observations
• First Results from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) Survey: Cosmological Reionization at z ~ 7
• Discovery of an Enormous Ly$\alpha$ nebula in a massive galaxy overdensity at $z=2.3$
• Effect of galaxy mergers on star formation rates
• A remarkably high fraction of strong Ly_alpha emitters amongst luminous redshift 6.0<z<6.5 Lyman break galaxies in the UKIDSS Ultra-Deep Survey
• Evolution of the Cool Gas in the Circumgalactic Medium (CGM) of Massive Halos -- A Keck Cosmic Web Imager (KCWI) Survey of Ly$\alpha$ Emission around QSOs at $z\approx 2$
• Searching for Extremely Blue UV Continuum Slopes at $z=7-11$ in JWST/NIRCam Imaging: Implications for Stellar Metallicity and Ionizing Photon Escape in Early Galaxies
• Star formation histories of UV-luminous galaxies at $z\simeq 6.8$: implications for stellar mass assembly at early cosmic times
• Spitzer and Hubble Constraints on the Physical Properties of the z~7 Galaxy Strongly Lensed by Abell 2218
• Central Powering of the Largest Lyman-alpha Nebula is Revealed by Polarized Radiation
• EPOCHS VI: The Size and Shape Evolution of Galaxies since z ~ 8 with JWST Observations
• Physical Properties of Spectroscopically-Confirmed Galaxies at z >= 6. II. Morphology of the Rest-Frame UV Continuum and Lyman-alpha Emission
• Measuring the properties of reionised bubbles with resolved Lyman alpha spectra
• The MUSE Hubble Ultra Deep Field Survey. IX. Evolution of galaxy merger fraction since z~6
• Physical Properties of Spectroscopically-Confirmed Galaxies at z >= 6. I. Basic Characteristics of the Rest-Frame UV Continuum and Lyman-alpha emission
• From Mirrors to Windows: Lyman-Alpha Radiative Transfer in a Very Clumpy Medium
• The Grism Lens-Amplified Survey from Space (GLASS). III. A census of Lyα Emission at $z\gtrsim$7 from HST Spectroscopy
• The ionising photon production efficiency at z~6 for Lyman-alpha emitters using JEMS and MUSE
• Constraining the physical properties of the first lensed $z\sim 10-16$ galaxy candidates with JWST
• On the UV compactness and morphologies of typical Lyman-a emitters from z~2 to z~6
• On the nature and physical conditions of the luminous Lya emitter CR7 and its rest-frame UV components
• What is the Physical Origin of Strong Lya Emission? I. Demographics of Lya Emitter Structures
• Four IRAC Sources with an Extremely Red H-[3.6] Color: Passive or Dusty Galaxies at z>4.5?
• EPOCHS VII: Discovery of high redshift ($6.5<z<12$) AGN candidates in JWST ERO and PEARLS data
• First results from Faint Infrared Grism Survey (FIGS): first simultaneous detection of Lyman-alpha emission and Lyman break from a galaxy at z=7.51
• Lyman-alpha spectroscopy of extreme [OIII] emitting galaxies at $z\simeq 2-3$: Implications for Ly$\alpha$ visibility and LyC leakage at $z>6$
• Luminous and High Stellar Mass Candidate Galaxies at z ~ 8 Discovered in CANDELS
• Frontier Fields : Combining HST, VLT and Spitzer data to explore the $z$$\sim$8 Universe behind the lensing cluster MACS0416$-$2403
• Stellar Properties of z ~ 8 Galaxies in the Reionization Lensing Cluster Survey
• The Magellan M2FS Spectroscopic Survey of High-$z$ Galaxies: Lyα Emitters at $z\approx 6.6$ and the Evolution of Lyα Luminosity Function over $z\approx 5.7-6.6$
• Young Galaxy Candidates in the Hubble Frontier Fields. II. MACS,J0416-2403
• Constraining Lyman-alpha spatial offsets at $3<z<5.5$ from VANDELS slit spectroscopy
• The Lensed Lyman-Alpha MUSE Arcs Sample (LLAMAS) : I. Characterisation of extended Lyman-alpha haloes and spatial offsets
• An Hα Impression of Lyα Galaxies at $z\simeq 6$ with Deep JWST/NIRCam Imaging
• The Ultraluminous Lyman Alpha Luminosity Function at z=6.6
• A Magellan M2FS Spectroscopic Survey of Galaxies at 5.5<z<6.8: Program Overview and a Sample of the Brightest Lyman-alpha Emitters
• Early Results from GLASS-JWST XXII: Rest frame UV-optical spectral properties of Lyman-alpha emitting galaxies at 3 $<$ z $<$ 6
• The Magellan M2FS Spectroscopic Survey of High-Redshift Galaxies: A Sample of 260 Ly$\alpha$ Emitters at Redshift $z\approx 5.7$
• Luminous Lyman-alpha Emitters with Very Blue UV-continuum Slopes at Redshift 5.7 <= z <= 6.6
• The Size and Pervasiveness of Ly$\alpha$-UV Spatial Offsets in Star-Forming Galaxies at $z\sim 6$
• CHORUS. III. Photometric and Spectroscopic Properties of Ly$\alpha$ Blobs at $z=4.9-7.0$
• First Light And Reionisation Epoch Simulations (FLARES) XIII: The Lyman-continuum emission of high-redshift galaxies
• Early Results from GLASS-JWST XXIII: The transmission of Lyman-alpha from UV-faint z ~ 3-6 galaxies
• Diffuse Lyman-alpha Halos around ~300 Spectroscopically Confirmed Lyman-alpha Emitters at z ~ 5.7
• The bright-end of the luminosity function at z~9
• The high-redshift Universe with Spitzer
• MOSEL survey: JWST reveals major mergers/strong interactions drive the extreme emission lines in the early universe
• Spectroscopically Identified Emission Line Galaxy Pairs in the WISP survey

Cited by in corpus (6)

• The JWST-PRIMAL Legacy Survey. A JWST/NIRSpec reference sample for the physical properties and Lyman-$\alpha$ absorption and emission of $\sim 500$ galaxies at $z=5.5-13.4$
• Peering into cosmic reionization: the Ly$\alpha$ visibility evolution from galaxies at $z$ = 4.5-8.5 with JWST
• Mapping reionization bubbles in the JWST era I: empirical edge detection with Lyman alpha emission from galaxies
• The Lyman-alpha and Continuum Origins Survey II: the connection between the escape of ionizing radiation and Lyman-alpha halos in star-forming galaxies
• A weak Ly$\alpha$ halo for an extremely bright Little Red Dot: Indications of enshrouded SMBH growth
• Extreme equivalent width-selected low-mass starbursts at $z=4-9$: insights into their role in cosmic reionization