MUSE integral-field spectroscopy towards the Frontier Fields cluster Abell S1063: II. Properties of low luminosity Lyman alpha emitters at z>3

Abstract

In spite of their conjectured importance for the Epoch of Reionization, the properties of low-mass galaxies are currently still under large debate. In this article, we study the stellar and gaseous properties of faint, low-mass galaxies at z>3. We observed the Frontier Fields cluster Abell S1063 with MUSE over a 2 arcmin^2 field, and combined integral-field spectroscopy with gravitational lensing to perform a blind search for intrinsically faint Lya emitters (LAEs). We determined in total the redshift of 172 galaxies of which 14 are lensed LAEs at z=3-6.1. We increased the number of spectroscopically-confirmed multiple-image families from 6 to 17 and updated our gravitational-lensing model accordingly. The lensing-corrected Lya luminosities are with L(Lya) <= 10^41.5 erg/s among the lowest for spectroscopically confirmed LAEs at any redshift. We used expanding gaseous shell models to fit the Lya line profile, and find low column densities and expansion velocities. This is to our knowledge the first time that gaseous properties of such faint galaxies at z>=3 are reported. We performed SED modelling to broadband photometry from the U-band through the infrared to determine the stellar properties of these LAEs. The stellar masses are very low (10^{6-8} Msun), and are accompanied by very young ages of 1-100 Myr. The very high specific star formation rates (~100 Gyr^-1) are characteristic of starburst galaxies. The UV-continuum slopes beta are low in our sample, with beta<-2 for all galaxies with M_star<10^8 Msun. We conclude that our low-mass galaxies at 3<z<6 are forming stars at higher rates when correcting for stellar mass effects than seen locally or in more massive galaxies. The young stellar populations with high star-formation rates and low HI column densities lead to continuum slopes and LyC-escape fractions expected for a scenario where low mass galaxies reionise the Universe.

46 pages, incl. 29 pages appendix, 17 figures, 4 tables, accepted for publication in A&A, abstract abridged

References in corpus (31)

• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Constraining the Low-Mass Slope of the Star Formation Sequence at 0.5<z<2.5
• A Bayesian approach to strong lensing modelling of galaxy clusters
• The Frontier Fields: Survey Design
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN
• Escape fraction of ionizing photons during reionization: effects due to supernova feedback and runaway OB stars
• Ly-alpha Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field South
• The Relation Between SFR and Stellar Mass for Galaxies at 3.5 $\le z\le$ 6.5 in CANDELS
• A Spectroscopic Redshift Measurement for a Luminous Lyman Break Galaxy at z=7.730 using Keck/MOSFIRE
• Mass and magnification maps for the Hubble Space Telescope Frontier Fields clusters: implications for high redshift studies
• A Population of Faint Extended Line Emitters and the Host Galaxies of Optically Thick QSO Absorption Systems
• The First Billion Years Project: The escape fraction of ionizing photons in the epoch of reionization
• Lens models and magnification maps of the six Hubble Frontier Fields clusters
• Can the intergalactic medium cause a rapid drop in Lyman alpha emission at z>6?
• 3D Lyman-alpha radiation transfer. III. Constraints on gas and stellar properties of z~3 Lyman break galaxies (LBG) and implications for high-z LBGs and Lyman-alpha emitters(LAEs)
• The LyA-LyC Connection: Evidence for an Enhanced Contribution of UV-faint Galaxies to Cosmic Reionization
• The VIMOS Ultra-Deep Survey (VUDS): fast increase of the fraction of strong Lyman alpha emitters from z=2 to z=6
• Lyman-alpha emitters gone missing: evidence for late reionization?
• A Luminosity Function of Lyman Alpha Emitting Galaxies at Redshift 4.5
• High-resolution spectroscopy of a young, low-metallicity optically-thin L=0.02L* star-forming galaxy at z=3.12
• Lyman alpha Radiative Transfer in Cosmological Simulations using Adaptive Mesh Refinement
• Ly$\alpha$ Spectra from Multiphase Outflows, and their Connection to Shell Models
• Where is the matter in the Merging Cluster Abell 2218?
• Directional Lya equivalent boosting I. Spherically symmetric distributions of clumps
• Spectral Energy Distribution Fitting of HETDEX Pilot Survey Lyman-alpha Emitters in COSMOS and GOODS-N
• How Lyman Alpha Emission Depends On Galaxy Stellar Mass
• Extreme emission-line galaxies out to z$\sim$1 in zCOSMOS. I. Sample and characterization of global properties
• Numerical simulations of dwarf galaxy merger trees
• The DEEP2 Redshift Survey: Lyman Alpha Emitters in the Spectroscopic Database
• Large-scale environment of $z\sim 5.7$ CIV absorption systems -II. Spectroscopy of Lyman-$\alpha$ emitters

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• The Frontier Fields: Survey Design
• Inferences on the Timeline of Reionization at z~8 From the KMOS Lens-Amplified Spectroscopic Survey
• Paving the way for the JWST: witnessing globular cluster formation at z>3
• Massive Star cluster formation under the microscope at z=6
• Mass distribution in the core of MACS J1206: robust modeling from an exceptionally large sample of central multiple images
• The MUSE Deep Lensed Field on the Hubble Frontier Field MACS~J0416
• Modeling $237$ Lyman-$\alpha$ spectra of the MUSE-Wide survey
• Fast Outflows Identified in Early Star-Forming Galaxies at $z=5-6$
• On the nature and physical conditions of the luminous Lya emitter CR7 and its rest-frame UV components
• Illuminating gas in-/outflows in the MUSE deepest fields: discovery of Ly-alpha nebulae around forming galaxies at z~3.3
• Dissection of the collisional and collisionless mass components in a mini sample of CLASH and HFF massive galaxy clusters at $z\approx 0.4$
• J1234+3901: an extremely metal-deficient compact star-forming dwarf galaxy at redshift 0.133
• The bursting nature of star formation in compact star-forming galaxies from the Sloan Digital Sky Survey
• Optical Line Emission from z$\sim$6.8 Sources with Deep Constraints on Ly$\alpha$ Visibility
• An Evaluation of 10 Lensing Models of the Frontier Fields Cluster MACSJ0416.1-2403
• A Magellan M2FS Spectroscopic Survey of Galaxies at 5.5<z<6.8: Program Overview and a Sample of the Brightest Lyman-alpha Emitters
• Hubble Frontier Field Photometric Catalogues of Abell 370 and RXC J2248.7-4431: Multiwavelength photometry, photometric redshifts, and stellar properties
• The Kormendy Relation of Galaxies in the Frontier Fields Clusters: Abell S1063 and MACS J1149.5+2223
• Evidence for the line of sight structure in the largest Hubble Frontier Field cluster, MACSJ0717.5+3745
• SuperBoRG: Search for The Brightest of Reionizing Galaxies and Quasars in HST Parallel Imaging Data
• Faint LAEs near z>4.7 CIV absorbers revealed by MUSE
• Probability of magnification in the $\text{Hubble Frontier Fields}$ clusters
• Exploring Effects on Magnifications due to Line-of-Sight Galaxies in the Hubble Frontier Fields
• SHARDS Frontier Fields: Physical properties of a low mass Lyman-alpha emitter at z=5.75
• Stellar feedback in a clumpy galaxy at $z\sim$ 3.4
• Star-formation rate in compact star-forming galaxies
• ALMA Lensing Cluster Survey: A spectral stacking analysis of [CII] in lensed $z\sim 6$ galaxies
• The Grism Lens-Amplified Survey from Space (GLASS). XIII. G800L optical spectra from the parallel fields
• AutoSpec: Fast Automated Spectral Extraction Software for IFU Datacubes