Faint galaxies in the Zone of Avoidance revealed by JWST/NIRCam

Abstract

The Zone of Avoidance (ZoA) remains one of the last frontiers in constructing a comprehensive three-dimensional map of the Universe. Galactic extinction, stellar crowding, and confusion noise have historically limited the detection of background galaxies in these regions, with implications for large-scale structure and cosmological measurements. We assess the capability of the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) to detect extragalactic sources in a heavily contaminated region of the Milky Way. We analyzed JWST/NIRCam wide-filter images of NGC 3324 with a customized implementation of SExtractor v2.28. Sources were detected in the F444W band, cross-matched with F090W and F200W, and validated against recent DAOPHOT point spread function (PSF) photometry. A refined sample was obtained through full width at half maximum (FWHM) - signal-to-noise ratio (SNR) criteria and visual inspection. We identified 102 galaxies across the JWST/NIRCam field of view. The magnitude (F444W) distribution is bimodal, with about 10% brighter than m_F444W < 15 mag and about 60% in the range 17 < m_F444W < 19 mag. Typical sizes are FWHM ~6.5 arcsec, from compact to extended systems with isophotal areas up to ~2000 pixels (~7.9 arcsec^2). Morphologies span from compact to spiral and lenticular systems, including a compact group at the eastern edge of the field. We also report the detection of "transnebular galaxies", visible through the most opaque regions of the molecular cloud. These results demonstrate the potential of JWST/NIRCam to probe extragalactic sources through highly obscured Galactic regions, opening new avenues for mapping large-scale structures across the ZoA.

arXiv commentAccepted for publication in Astronomy & Astrophysics (Section 4: Extragalactic Astronomy). Minor editorial corrections pending (reference updates and JWST typesetting)

References in corpus (67)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Gaia Data Release 3: Summary of the content and survey properties
• The 6dF Galaxy Survey: Baryon Acoustic Oscillations and the Local Hubble Constant
• The 2dF Galaxy Redshift Survey: Spectra and redshifts
• A 2.4% Determination of the Local Value of the Hubble Constant
• The 3D power spectrum of galaxies from the SDSS
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• The Pantheon+ Analysis: Cosmological Constraints
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• The size distribution of galaxies in the Sloan Digital Sky Survey
• Galaxy and Mass Assembly (GAMA): survey diagnostics and core data release
• The 6dF Galaxy Survey: Final Redshift Release (DR3) and Southern Large-Scale Structures
• VISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way
• Power Spectrum Analysis of Three-Dimensional Redshift Surveys
• Cosmicflows-3
• Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak
• The Mid-Infrared Instrument for the James Webb Space Telescope I: Introduction
• NIRCam Performance on JWST In Flight
• The VIMOS Public Extragalactic Redshift Survey (VIPERS). An unprecedented view of galaxies and large-scale structure at 0.5<z<1.2
• The Early Data Release of the Dark Energy Spectroscopic Instrument
• The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Testing gravity with redshift-space distortions using the power spectrum multipoles
• The JWST Early Release Observations
• The Mid-Infrared Instrument for JWST, II: Design and Build
• Galaxy Groups: A 2MASS Catalog
• Near-IR Atlas of S0-Sa galaxies (NIRS0S)
• The Cosmic Web: Geometric Analysis
• The Dipole Anisotropy of the 2 Micron All-Sky Redshift Survey
• Cosmography of the Local Universe
• 2MASS Extended Sources in the Zone of Avoidance
• The Near-infrared S0 Survey III: Morphology of 15 Southern Early-type Disk Galaxies
• Rapid modelling of the redshift-space power spectrum multipoles for a masked density field
• Wiener Reconstruction of Galaxy Surveys in Spherical Harmonics
• A Census of the Carina Nebula -- II. Energy Budget and Global Properties of the Nebulosity
• The Universe behind the Milky Way
• Integral constraints in spectroscopic surveys
• The Parkes HI Zone of Avoidance Survey
• Herschel far-infrared observations of the Carina Nebula complex I: Introduction and global cloud structure
• The Norma Cluster (ACO 3627): I. A Dynamical Analysis of the Most Massive Cluster in the Great Attractor
• Herschel far-infrared observations of the Carina Nebula Complex. - III: Detailed cloud structure and feedback effects
• Discovery of a supercluster in the ZOA in Vela
• Early results from GLASS-JWST. II: NIRCam extra-galactic imaging and photometric catalog
• The Clustering Dipole of the Local Universe from the Two Micron All Sky Survey
• SIBELIUS-DARK: a galaxy catalogue of the Local Volume from a constrained realisation simulation
• Dark Energy Survey: A 2.1% measurement of the angular Baryonic Acoustic Oscillation scale at redshift $z_{\mathrm{eff}}$=0.85 from the final dataset
• The HI Parkes Zone of Avoidance Survey: the Northern Extension
• The VISTA Variables in the Vía Láctea eXtended (VVVX) ESO public survey: Completion of the observations and legacy
• The 2MASS Redshift Survey in the Zone of Avoidance
• The effect of cosmic web filaments on galaxy evolution
• The WSRT ZoA Perseus-Pisces Filament wide-field HI imaging survey I. HI catalogue and atlas
• Gaia EDR3 distances of the young stellar clusters in the extended Carina Nebula complex
• The Arecibo L-band Feed Array Zone of Avoidance Survey I: Precursor Observations through the Inner and Outer Galaxy
• The Nancay HI Zone of Avoidance survey of 2MASS bright galaxies
• Searching for Extragalactic Sources in the VISTA Variables in the Vía Láctea Survey
• An Overview of Uncovered and Suspected Large-Scale Structures behind the Milky Way
• The VVV Near-IR Galaxy Catalogue beyond the Galactic disk
• Deep diving off the `Cosmic Cliffs': previously hidden outflows in NGC 3324 revealed by JWST
• Predicting Structures in the Zone of Avoidance
• The First Galaxy Cluster Discovered by the VISTA Variables in the Vía Láctea Survey
• Overdensity of VVV galaxies behind the Galactic bulge
• The VVV near-IR galaxy catalogue in a Northern part of the Galactic disc
• A deep near-infrared view of the Ophiuchus galaxy cluster
• A Local Universe model for constrained simulations
• Challenges to the cosmological constant model following results from the Dark Energy Survey