ALMA Lensing Cluster Survey: an ALMA galaxy signposting a MUSE galaxy group at z=4.3 behind 'El Gordo'

Abstract

We report the discovery of a Multi Unit Spectroscopic Explorer (MUSE) galaxy group at z=4.32 lensed by the massive galaxy cluster ACT-CL J0102-4915 (aka El Gordo) at z=0.87, associated with a 1.2 mm source which is at a 2.07+/-0.88 kpc projected distance from one of the group galaxies. Three images of the whole system appear in the image plane. The 1.2 mm source has been detected within the Atacama Large Millimetre/submillimetre Array (ALMA) Lensing Cluster Survey (ALCS). As this ALMA source is undetected at wavelengths lambda < 2 microns, its redshift cannot be independently determined, however, the three lensing components indicate that it belongs to the same galaxy group at z=4.32. The four members of the MUSE galaxy group have low to intermediate stellar masses (~ 10^7-10^{10} Msun) and star formation rates (SFRs) of 0.4-24 Msun/yr, resulting in high specific SFRs (sSFRs) for two of them, which suggest that these galaxies are growing fast (with stellar-mass doubling times of only ~ 2x10^7 years). This high incidence of starburst galaxies is likely a consequence of interactions within the galaxy group, which is compact and has high velocity dispersion. Based on the magnification-corrected sub-/millimetre continuum flux density and estimated stellar mass, we infer that the ALMA source is classified as an ordinary ultra-luminous infrared galaxy (with associated dust-obscured SFR~200-300 Msun/yr) and lies on the star-formation main sequence. This reported case of an ALMA/MUSE group association suggests that some presumably isolated ALMA sources are in fact signposts of richer star-forming environments at high redshifts.

13 pages including 7 figures and 1 table. Accepted for publication at the ApJ. Minor changes with respect to version 1. Figure 6 has been expanded to broaden comparison with the literature

References in corpus (17)

• Star Formation in AEGIS Field Galaxies since z=1.1 : The Dominance of Gradually Declining Star Formation, and the Main Sequence of Star-Forming Galaxies
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• Dust temperature and mid-to-total infrared color distributions for star-forming galaxies at 0<z<4
• The Star Formation Main Sequence in the Hubble Space Telescope Frontier Fields
• ALMA Imaging of Gas and Dust in a Galaxy Protocluster at Redshift 5.3: [CII] Emission in "Typical" Galaxies and Dusty Starbursts ~1 Billion Years after the Big Bang
• Paving the way for the JWST: witnessing globular cluster formation at z>3
• Gas filaments of the cosmic web located around active galaxies in a proto-cluster
• An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Near-infrared morphologies and stellar sizes
• Gas Fraction and Depletion Time of Massive Star Forming Galaxies at z~3.2: No Change in Global Star Formation Process out to z>3
• The H alpha Galaxy Survey. VIII. Close companions and interactions, and the definition of starbursts
• MUSE integral-field spectroscopy towards the Frontier Fields Cluster Abell S1063: I. Data products and redshift identifications
• Illuminating gas in-/outflows in the MUSE deepest fields: discovery of Ly-alpha nebulae around forming galaxies at z~3.3
• Analysis of the SFR - M* plane at z<3: single fitting versus multi-Gaussian decomposition
• A radio-to-mm census of star-forming galaxies in protocluster 4C23.56 at z=2.5 : Gas mass and its fraction revealed with ALMA
• PdBI Cold Dust Imaging of Two Extremely Red H-[4.5]>4 Galaxies Discovered with SEDS and CANDELS
• Highly-magnified, Multiply-imaged radio counterparts of the Sub-mm Starburst Emission in the Cluster-Lens MS0451.6-0305

Cited by in corpus (20)

• JWST's PEARLS: Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results
• JWST unveils heavily obscured (active and passive) sources up to z~13
• Mapping Obscuration to Reionization with ALMA (MORA): 2mm Efficiently Selects the Highest-Redshift Obscured Galaxies
• MIDIS: Strong (Hb + [OIII]) and Ha emitters at redshift $z\simeq 7-8$ unveiled with JWST/NIRCam and MIRI imaging in the Hubble eXtreme Deep Field (XDF)
• JWST's PEARLS: a new lens model for ACT-CL J0102$-$4915, "EL Gordo'', and the first red supergiant star at cosmological distances discovered by JWST
• Mining for Strong Gravitational Lenses with Self-supervised Learning
• MIRI/JWST observations reveal an extremely obscured starburst in the z=6.9 system SPT0311-58
• ALMA Lensing Cluster Survey: ALMA-Herschel Joint Study of Lensed Dusty Star-Forming Galaxies across $z\simeq 0.5-6$
• JWST's PEARLS: A JWST/NIRCam view of ALMA sources
• $JWST$ Insight Into a Lensed $HST$-dark Galaxy and its Quiescent Companion at $z=2.58$
• Paper 1: The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies
• A MUSE view of the massive merging galaxy cluster ACT-CL J0102-4915 (El Gordo) at z = 0.87: robust strong lensing model and data release
• Probing the Star Formation Main Sequence down to $10^8$ M${}_{\odot }$ at $1.0<z<3.0$
• JWST/MIRI unveils the stellar component of the GN20 dusty galaxy overdensity at $z$=4.05
• Euclid: Identifying the reddest high-redshift galaxies in the Euclid Deep Fields with gradient-boosted trees
• "Dust Giant": Extended and Clumpy Star-Formation in a Massive Dusty Galaxy at $z=1.38$
• PASSAGES: The Discovery of a Strongly Lensed Protocluster Core Candidate at Cosmic Noon
• ALMA Lensing Cluster Survey: average dust, gas, and star formation properties of cluster and field galaxies from stacking analysis
• Extensive Lensing Survey of Optical and Near-Infrared Dark Objects (El Sonido): HST H-Faint Galaxies behind 101 Lensing Clusters
• The galaxy starburst/main-sequence bimodality over five decades in stellar mass at z ~ 3-6.5