20.2.7 mcmc_samples_gsp_phot
This is the DataLink table hosting Monte-Carlo Markov Chain (MCMC) samples for the posterior probability distribution of all parameters derived from the General Stellar Parametrizer from Photometry (GSP-Phot, see Section 11.3.3 in the online documentation). 2000 MCMC samples are provided for 1) all sources brighter than G=12, 2) a random subset of 1% of the sources fainter than G=12. For all other sources fainter than G=12, the sample size is 100 (the last 100 samples in the MCMC).
The table considers the following parameters:
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effective temperature in K
- •
monochromatic extinction at 541.4 nm in mag
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surface gravity
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metallicity [M/H]
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-band extinction in mag
- •
absolute magnitude in mag
- •
distance in pc
- •
band extinction in mag
- •
band extinction in mag
- •
reddening in mag
- •
logarithmic posterior probability
- •
logarithmic likelihood
- •
stellar radius in
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_mcmc_gspphot = 't'.
Columns description:
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
A unique single numerical identifier of the source obtained from gaia_source (for a detailed description see gaia_source.source_id).
The sample size is 100 for most sources, and is set to 2000 for 1) all sources brighter than G=12, 2) a random sample of 0.1% of the sources fainter than G=12.
MCMC samples for posterior probability distribution of the stellar effective temperature from GSP-Phot.
MCMC samples for posterior probability distribution of the monochromatic extinction at 541.4 nm from GSP-Phot.
MCMC samples for posterior probability distribution of the stellar surface gravity from GSP-Phot.
MCMC samples for posterior probability distribution of metallicity [M/H] from GSP-Phot.
MCMC samples for posterior probability distribution of the extinction in the G band from GSP-Phot.
MCMC samples for posterior probability distribution of the absolute magnitude in the G band from GSP-Phot. The value is obtained from isochrones (for details see Section 11.3.3 in the online documentation).
MCMC samples for posterior probability distribution of the distance from GSP-Phot.
MCMC samples for posterior probability distribution of the extinction in the band from GSP-Phot.
MCMC samples for posterior probability distribution of the extinction in the band from GSP-Phot.
MCMC samples for posterior probability distribution of the reddening from GSP-Phot.
Logarithmic posterior probability of MCMC samples from GSP-Phot. This can be used in order to replace the GSP-Phot priors by a user-chosen prior using importance sampling (for details see Section 11.3.3 in the online documentation).
Logarithmic likelihood of MCMC samples from GSP-Phot. This can be used in order to replace the GSP-Phot priors by a user-chosen prior using importance sampling (for details see Section 11.3.3 in the online documentation).
radius : MCMC samples for stellar radius from GSP-Phot (float[nsamples] array, Length & Distance[Solar Radius])
MCMC samples for posterior probability distribution of the stellar radius from GSP-Phot.