Webb's PEARLS: Bright 1.5--2.0 micron Dropouts in the Spitzer/IRAC Dark Field

Abstract

Using the first epoch of four-band NIRCam observations obtained by the James Webb Space Telescope (JWST) Prime Extragalactic Areas for Reionization and Lensing Science Program in the Spitzer IRAC Dark Field, we search for F150W and F200W dropouts. In 14.2 arcmin^2, we have found eight F150W dropouts and eight F200W dropouts, all brighter than 27.5 mag (the brightest being ~24 mag) in the band to the red side of the break. As they are detected in multiple bands, these must be real objects. Their nature, however, is unclear, and characterizing their properties is important for realizing the full potential of JWST. If the observed color decrements are due to the Lyman break, these objects should be at z >~ 11.7 and z >~ 15.4, respectively. The color diagnostics show that at least four F150W dropouts are far away from the usual contaminators encountered in dropout searches (red galaxies at much lower redshifts or brown dwarf stars). While the diagnostics of the F200W dropouts are less certain due to the limited number of passbands, at least one of them is likely not a known type of contaminant, and the rest are consistent with either high-redshift galaxies with evolved stellar populations or old galaxies at z ~ 3 to 8. If a significant fraction of our dropouts are indeed at z ~ 12, we have to face the severe problem of explaining their high luminosities and number densities. Spectroscopic identifications of such objects are urgently needed.

Accepted for publication in ApJL

References in corpus (15)

• EAZY: A Fast, Public Photometric Redshift Code
• A luminous quasar at a redshift of z = 7.085
• A Luminous Quasar at Redshift 7.642
• Two Remarkably Luminous Galaxy Candidates at $z\approx 10-12$ Revealed by JWST
• The evolution of the galaxy UV luminosity function at redshifts z ~ 8-15 from deep JWST and ground-based near-infrared imaging
• Pōniuā'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole
• A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
• Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15
• 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 JWST Early Release Observations
• 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
• Evidence for GN-z11 as a luminous galaxy at redshift 10.957
• First Light And Reionisation Epoch Simulations (FLARES) VI: The colour evolution of galaxies $z=5-15$

Cited by in corpus (10)

• Early Results from GLASS-JWST. XIX: A High Density of Bright Galaxies at $z\approx 10$ in the Abell 2744 Region
• Blue Monsters. Why are JWST super-early, massive galaxies so blue?
• EPOCHS IV: SED Modelling Assumptions and their impact on the Stellar Mass Function at 6.5 < z < 13.5 using PEARLS and public JWST observations
• The GLASS-JWST Early Release Science Program. II. Stage I release of NIRCam imaging and catalogs in the Abell 2744 region
• Delving deep: a population of extremely dusty dwarfs observed by JWST
• Dust-free starburst galaxies at redshifts $z>10$
• FORECAST: a flexible software to forward model cosmological hydrodynamical simulations mimicking real observations
• Point-like sources among z>11 galaxy candidates: contaminants due to supernovae at high redshifts?
• NOEMA reveals the true nature of luminous red JWST z>10 galaxy candidates
• The Parallel Ionizing Emissivity Survey (PIE). I. Survey design and selection of candidate Lyman Continuum leakers at 3.1<z<3.5