Siena Galaxy Atlas¶
The Siena Galaxy Atlas (SGA) is a multiwavelength, diameter-limited atlas of nearby galaxies built using the DESI Legacy Imaging Surveys (the Legacy Surveys). For each galaxy, the SGA delivers precise coordinates, multiwavelength mosaics, azimuthally averaged surface-brightness and color profiles, integrated and aperture photometry, and additional metadata. Because large, resolved galaxies trace the foreground extragalactic sky, the SGA also serves as a foundational reference catalog for wide-field cosmological surveys such as the Dark Energy Spectroscopic Instrument (DESI).
⚠️ Not yet publicly released — draft, subject to change
Current release (v1.0) — 470,625 galaxies over 30,000 deg²
griz optical (DR11) · unWISE W1–W4 · GALEX FUV/NUV
Web gallery (draft): dr11-north · dr11-south
Released August 2026
383,620 galaxies over 20,000 deg²
grz optical (DR9) · unWISE W1–W4
Web gallery: https://sga.legacysurvey.org
Released January 2021
Getting Started
Data Releases
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