Forced source

Forced measurements in visit and difference images, at the coordinates of all objects.

Schema: ForcedSource table

Access

The forced source catalog is accessible via the TAP and Butler services.

Recommended access service: TAP

TAP

  • Citation: NSF-DOE Vera C. Rubin Observatory (2025); Legacy Survey of Space and Time Data Preview 1: ForcedSource searchable catalog DOI Logo https://doi.org/10.71929/rubin/2570327

  • Table name: ForcedSource

  • Columns: 28

  • Rows: 268,796,943

Butler

  • Citation: NSF-DOE Vera C. Rubin Observatory (2025); Legacy Survey of Space and Time Data Preview 1: object_forced_source dataset type DOI Logo https://doi.org/10.71929/rubin/2570326

  • Dataset type: (‘object_forced_source’, {skymap, tract, patch}, ArrowAstropy)

  • Format: Parquet

  • Number of Butler datasets: 636

Description

“Forced” photometry means a measurement made at a fixed coordinate in an image, regardless of whether an above-threshold region was detected there in that particular image.

The forced source catalog contains forced PSF flux photometry on both the visit (i.e., “science” or “direct”) and difference images at the coordinates of every object in the object table.

Processing

The forced source catalog is the result of Source detection and measurement.

Tutorials

See the 200-level notebook or 200-level portal tutorials demonstrating how to access the forced source table.