SDWFS: Spitzer Infrared Galaxy Survey with Four Epochs

Four-epoch infrared survey of 10 square degrees in the Boötes field, permitting the selection of variable and high proper motion objects over years. The Spitzer Cycle 4 Legacy project data consists of 20 band-matched catalogs reporting Vega magnitudes in four IRAC bands. NASA's delivery includes source measurements from three aperture types with coordinates matched to 2MASS positions.

Use Cases

• Identify infrared-variable astronomical objects based on multi-epoch observations over years.
• Study galaxy evolution beyond redshift ~1.5 based on the survey's sensitivity and large volume.
• Select high proper motion objects based on positional changes measured across four epochs.
• Characterize photometric properties of sources based on three measurement apertures (4", 6", Kron).

Strengths

• Covers a unique 10 square degree area-depth parameter space for infrared surveys.
• Provides four epochs of data enabling time-domain analysis over years.
• Coordinates are matched to 2MASS catalog positions within 0.2 arcsec accuracy.
• Reports Vega magnitudes in four IRAC bands (3.6, 4.5, 5.8, 8 microns) with three measurement apertures per source.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Uncertainties are reported as twice the SExtractor statistical uncertainties, indicating an attempt to account for systematics but not a direct measurement.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Observations from the IRAC instrument on the Spitzer Space Telescope, processed with SExtractor.

Time Range

Covers four observational epochs (timescales of years).

Freshness

Last updated 2026-03-13 20:05:10.042688; freshness should be verified.

Geography

10 square degrees in the Boötes field of the NOAO Deep Wide-Field Survey.