Wavelength sampling used for inferring astrophysical parameters in Gaia DR3

The astrophysical parameters in Gaia DR3 are produced by the Astrophysical Parameters Inference System (Apsis, Creevey et al. 2022). Many of the results from Apsis are based on the use of the BP and RP spectra (De Angeli, et al. 2022, Mongetgriffo et al. 2022). Within Apsis a fixed wavelength sampling of the BP and the RP spectra was used, and here this parameter file is provided to the user:

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The wavelength sampling scheme is approximately equidistant in pixel sample space. Thus, due to the nonlinear dispersion relation, the width of the samples is varying in physical wavelength. The spectral resolution of this sampling scheme is slowly decreasing with increasing wavelength for both, BP and RP.

References

• Gaia Data Release 3: Astrophysical parameters inference system (Apsis) I - overview; Creevey, Sordo, Pailler et al. 2022, A&A
• Gaia Data Release 3: Processing and validation of BP/RP low-resolution spectral data; De Angeli, et al. 2022, A&A
• Gaia Data Release 3: External calibration of the low-resolution spectroscopic data; Montegriffo et al. 2022, A&A

Acknowledgements

This product makes use of auxiliary data provided by ESA/Gaia/DPAC/CU8-CU5 for ESA/Gaia/DPAC/CU8 and has been prepared by Rene Andrae, Rosanna Sordo, Paolo Montegriffo.

​​​​​​Published: 13 June 2022