SAGE-SMC IRAC Catalog: Multi-Epoch Infrared Observations of the Small Magellanic Cloud

A multi-epoch infrared catalog from the Spitzer Space Telescope's SAGE-SMC legacy program, mapping the Small Magellanic Cloud. The data includes observations from three epochs (Epoch 0, 1, and 2) separated by months to remove imaging artifacts and constrain source variability. The catalog was produced by a team led by Karl Gordon (STScI) and is hosted by the National Aeronautics and Space Administration.

Use Cases

• Detecting and analyzing variable stars based on multi-epoch infrared flux measurements.
• Studying young stellar objects (YSOs) in the tidally-disrupted Small Magellanic Cloud.
• Removing imaging artifacts from infrared data using observations at different roll angles.
• Cross-matching infrared sources with 2MASS K_s band data for multi-wavelength analysis.

Strengths

• Implements strict detection criteria: sources must be detected in at least 60% of observations at a wavelength and have S/N greater than [5, 5, 5, 7] for IRAC bands.
• Uses multiple observation epochs (separated by 3 and 9 months) to remove striping and column/row artifacts and constrain variability.
• Catalog sources are culled to exclude neighbors within a 2" radius, likely improving source isolation.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The description notes the archive has more sources but with greater uncertainty, suggesting the catalog is a high-reliability subset.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Infrared observations from the Spitzer Space Telescope's IRAC and MIPS instruments, reduced with consistent software.

Time Range

Observations from three epochs (Epoch 0, 1, and 2), with Epochs 1 and 2 separated by 3 (IRAC) and 9 (MIPS) months.

Freshness

Last updated 2026-03-13 17:18:37.411418; freshness should be verified.

Geography

Small Magellanic Cloud, with Epoch 0 covering the inner 3 square degrees.