20.13.5 vari_agn
This table provides information on AGN properties.
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 fractional variability is calculated as ,
where is the Median Absolute Deviation (MAD) of the field-of-view transit fluxes in the band, the mean square of flux uncertainties , and is the median flux of the field-of-view transits in the band.
Index of the first-order structure function (SF; Simonetti et al. 1985), i.e., slope in the logSF vs logTau space, where Tau is the time lag. The SF is expressed in magnitude squared and computed from field-of-view transit magnitudes in the band. The index is linked to that of the Fourier power spectrum and indicates the type of noise process at work.
structure_function_index_scatter : Standard deviation of the index of the structure function (float)
Standard deviation of the index of the structure function (i.e., slope in the logSF vs logTau space). The structure function is expressed in magnitude square. The index is linked to the power of the Fourier power spectrum and indicates the type of noise process at work. AGN should show , in between flicker noise () and shot (random walk) noise ().
Quasar variability metric from field-of-view transit magnitudes in the band in log format, , from Butler and Bloom (2011), after adaptation to Gaia data.
Non-quasar variability metric from field-of-view transit magnitudes in the band in log format, ), from Butler and Bloom (2011), after adaptation to Gaia data.