This page collects some information useful to learn how to use the Gaia BP/RP spectra

General recommendations:

• Use BP/RP spectra coefficients when possible (not sampled spectra or synthetic photometry). Move away from coefficients only if there is a good reason for doing so!

• Use internally calibrated spectra (less systematics present). Go to externally calibrated spectra only for things that cannot be done with internally calibrated spectra.

• Do not use standard spectroscopic techniques naively! Think again if what you are doing is adequate and justified!

Papers to read:

• BP/RP internal spectra calibration model: Carrasco et al. (2021): Internal calibration of Gaia BP/RP low-resolution spectra 

• Processing for Gaia DR3: De Angeli et al (2022). Gaia Data Release 3: Processing and validation of BP/RP low-resolution spectral data 

• BP/RP external calibration: Montegriffo et al (2022). Gaia Data Release 3: External calibration of BP/RP low-resolution spectroscopic data 

• Synthetic photometry from BP/RP spectra: Montegriffo et al (2022). Gaia Data Release 3: The Galaxy in your preferred colours. Synthetic photometry from Gaia low-resolution spectra 

• How to analyse spectral lines in BP/RP spectra: Weiler et al (2022): Analysing spectral lines in Gaia low-resolution spectra

Videos:

How to download BP/RP data:

In Gaia catalogue webpage, go to the ADQL search and select those sources in gaiasource table with has_xp_continuous='True'. When the list of source_id is retrieved in a table, go to the Datalink icon and select to download the "XP mean continuous spectra". We recommend to download only the continuous spectra, not the sampled one. Not all sources have the sampled mean spectra, only few. From the continuous spectra you can derive the sampled spectra (for example using GaiaXPy tool).

How to use GaiaXPy (SPANISH):

GaiaXPy is a Python code able to transform the BP/RP coefficients into sampled internal or external spectra and to generate synthetic photometry from the spectra. Nevertheless, we always recommend to directly use the coefficients for scientific quantitative purposes and use this tool only for illustration.

Hands on session for the use of BP/RP spectra (Madrid, 20/10/2022, SPANISH)

Link to the programme of the session: https://gaia.ub.edu/twiki/do/view/RecGaia/EspectrosXP