# 20.12.4 xp_sampled_mean_spectrum

This is the BP/RP externally calibrated sampled mean spectrum. All mean spectra are sampled to the same set of absolute wavelength positions, viz. 343 values from 336 to 1020 nm with a step of 2 nm.

Note this table is not available through the main archive TAP interface. Data are delivered via the Massive Data service indexed by the VO Datalink protocol and described in Chapter 18. For example this can be actioned in the archive user interface by querying the main source catalogue gaia_source and selecting has_xp_sampled = 't'.

Columns description:

source_id : Unique source identifier (unique within a particular Data Release) (long)

A unique single numerical identifier of the source obtained from gaia_source (for a detailed description see gaia_source.source_id).

solution_id : Solution Identifier (long)

All Gaia data processed by the Data Processing and Analysis Consortium comes tagged with a solution identifier. This is a numeric field attached to each table row that can be used to unequivocally identify the version of all the subsystems that were used in the generation of the data as well as the input data used. It is mainly for internal DPAC use but is included in the published data releases to enable end users to examine the provenance of processed data products. To decode a given solution ID visit https://gaia.esac.esa.int/decoder/solnDecoder.jsp

ra : Right Ascension (double, Angle[deg])

Barycentric Right Ascension $\alpha$ of object in ICRS at reference epoch ref_epoch as given in the main gaia_source table.

dec : Declination (double, Angle[deg])

Barycentric Declination $\delta$ of object in ICRS at reference epoch ref_epoch as given in the main gaia_source table.

flux : mean BP + RP combined spectrum flux (float[] array, Flux[W m${}^{-2}$ nm${}^{-1}$])

Externally-calibrated combined BP and RP flux.

flux_error : mean BP + RP combined spectrum flux error (float[] array, Flux[W m${}^{-2}$ nm${}^{-1}$])

Externally-calibrated combined BP and RP flux error.