000006069 001__ 6069
000006069 005__ 20240108165054.0
000006069 0247_ $$2DOI$$a10.1051/0004-6361/202244507
000006069 037__ $$aSCART-2023-0030
000006069 100__ $$aSarro, L. M.
000006069 245__ $$aUltracool dwarfs in Gaia DR3 
000006069 260__ $$c2023
000006069 520__ $$aContext. Previous Gaia Data Releases offered the opportunity to uncover ultracool dwarfs (UCDs) through astrometric, rather than purely photometric selection. The most recent, third data release offers in addition the opportunity to use low-resolution spectra to refine and widen the selection. Aims. In this work we use the Gaia DR3 set of ultracool dwarf candidates and complement the Gaia spectrophotometry with additional photometry in order to characterise its global properties. This includes the inference of the distances, their locus in the Gaia colour-absolute magnitude diagram and the (biased through selection) luminosity function in the faint end of the Main Sequence. We study the overall changes in the Gaia RP spectra as a function of spectral type. We study the UCDs in binary systems, attempt to identify low-mass members of nearby young associations, star forming regions and clusters, and analyse their variability properties. Methods. We use a forward model and the Bayesian inference framework to produce posterior probabilities for the distribution parameters and a calibration of the colour index as a function of the absolute magnitude in the form of a Gaussian Process. Additionally we apply the HMAC unsupervised classification algorithm for the detection and characterisation of overdensities in the space of celestial coordinates, projected velocities and parallaxes. Results. We detect 57 young, kinematically homogeneous groups some of which are identified as well known star forming regions, associations and clusters of different ages. We find that the primary members of 880 binary systems with a UCD belong mainly to the thin and thick disk components of the Milky Way. We identify 1109 variable UCDs using the variability tables in the Gaia archive, 728 of which belong to the star forming regions defined by HMAC. We define two groups of variable UCDs with extreme bright or faint outliers. Conclusions. The set of sources identified as UCDs in the Gaia archive contains a wealth of information that will require focused follow-up studies and observations. It will help to advance our understanding of the nature of the faint end of the Main Sequence and the stellar/substellar transition.
000006069 536__ $$aGaia PRODEX/$$cGaia PRODEX/$$fGaia PRODEX
000006069 594__ $$aNO
000006069 6531_ $$aMethods: statistical
000006069 6531_ $$aCatalogs
000006069 6531_ $$aStars: brown dwarfs
000006069 6531_ $$aStars: low-mass
000006069 6531_ $$aStars: late-type
000006069 6531_ $$aStars: Hertzsprung-Russell and C-M diagrams
000006069 6531_ $$aStars: luminosity function, mass function
000006069 6531_ $$aStars: binaries: general
000006069 6531_ $$aStars: pre-main sequence
000006069 6531_ $$aStars: variables: general
000006069 700__ $$aBerihuete, A.
000006069 700__ $$aSmart, R. L.
000006069 700__ $$aReylé, C.
000006069 700__ $$aBarrado, D.
000006069 700__ $$aGarcía-Torres, M.
000006069 700__ $$aCooper, W. J.
000006069 700__ $$aJones, H. R. A.
000006069 700__ $$aMarocco, F.
000006069 700__ $$aCreevey, O. L.
000006069 700__ $$aSordo, R.
000006069 700__ $$aBailer-Jones, C. A. L.
000006069 700__ $$aMontegriffo, P.
000006069 700__ $$aCarballo, R.
000006069 700__ $$aAndrae, R.
000006069 700__ $$aFouesneau, M.
000006069 700__ $$aLanzafame, A. C.
000006069 700__ $$aPailler, F.
000006069 700__ $$aThévenin, F.
000006069 700__ $$aLobel, A.
000006069 700__ $$aDelchambre, L.
000006069 700__ $$aKorn, A. J.
000006069 700__ $$aRecio-Blanco, A.
000006069 700__ $$aSchultheis, M. S.
000006069 700__ $$aDe Angeli, F.
000006069 700__ $$aBrouillet, N.
000006069 700__ $$aCasamiquela, L.
000006069 700__ $$aContursi, G.
000006069 700__ $$ade Laverny, P.
000006069 700__ $$aGarcía-Lario, P.
000006069 700__ $$aKordopatis, G.
000006069 700__ $$aLebreton, Y.
000006069 700__ $$aLivanou, E.
000006069 700__ $$aLorca, A.
000006069 700__ $$aPalicio, P. A.
000006069 700__ $$aSlezak-Oreshina, I.
000006069 700__ $$aSoubiran, C.
000006069 700__ $$aUlla, A.
000006069 700__ $$aZhao, H.
000006069 773__ $$cA139 (25pp)$$pAstronomy & Astrophysics$$v669$$y2023
000006069 8560_ $$fronny.blomme@observatoire.be
000006069 85642 $$ahttps://ui.adsabs.harvard.edu/abs/2022arXiv221103641S/abstract
000006069 85642 $$ahttps://arxiv.org/abs/2211.03641
000006069 905__ $$apublished in
000006069 980__ $$aREFERD