/ftp/cats/i/352



==========================================================================
I/352        Distances to 1.47 billion stars in Gaia EDR3  (Bailer-Jones+, 2021)
The following files can be converted to FITS (extension .fit or fit.gz)
	gedr3dis.sam
==========================================================================
Query from: http://vizier.cds.unistra.fr/viz-bin/VizieR?-source=I/352
==========================================================================

drwxr-xr-x 317 cats archive 8192 Feb 28 11:16 [Up] drwxr-xr-x 3 cats archive 4096 Jan 8 16:54 [TAR file] -rw-r--r-- 1 cats archive 462 Jan 8 16:53 .message -r--r--r-- 1 cats archive 6861 Apr 28 2021 ReadMe -rw-r--r-- 1 cats archive 1005 Jan 8 16:53 +footg5.gif -rw-r--r-- 1 cats archive 6759 Jan 8 16:54 +footg5.png -rw-r--r-- 1 cats archive 2978 Jan 8 16:53 +footg8.gif -rw-r--r-- 1 cats archive 36870 Jan 8 16:54 +footg8.png -r--r--r-- 1 cats archive 148000 Feb 25 2021 gedr3dis.sam -rw-r--r-- 1 cats archive 80640 Aug 22 2022 tab_1352_1_I_352_gedr3dis.moc.fits
Beginning of ReadMe : I/352 Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021) ================================================================================ Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3. Bailer-Jones C.A.L., Rybizki J., Fouesneau M., Demleitner M., Andrae R . <Astron. J. 161, 147 (2021)> =2021AJ....161..147B =2021yCat.1352....0B ================================================================================ ADC_Keywords: Surveys ; Stars, distances Keywords: catalogs - Galaxy: structure - methods: statistical - stars: distances - parallax Abstract: Stellar distances constitute a foundational pillar of astrophysics. The publication of 1.47 billion stellar parallaxes from Gaia is a major contribution to this. Yet despite Gaia's precision, the majority of these stars are so distant or faint that their fractional parallax uncertainties are large, thereby precluding a simple inversion of parallax to provide a distance. Here we take a probabilistic approach to estimating stellar distances that uses a prior constructed from a three-dimensional model of our Galaxy. This model includes interstellar extinction and Gaia's variable magnitude limit. We infer two types of distance. The rst, geometric, uses the parallax together with a direction-dependent prior on distance. The second, photogeometric, additionally uses the colour and apparent magnitude of a star, by exploiting the fact that stars of a given colour have a restricted range of probable absolute magnitudes (plus extinction). Tests on simulated data and external validations show that the photogeometric estimates generally have higher accuracy and precision for stars with poor parallaxes. We provide a catalogue of 1.47 billion geometric and 1.35 billion photogeometric distances together with asymmetric uncertainty measures. Our estimates are quantiles of a posterior probability distribution, so they transform invariably and can therefore also be used directly in the distance modulus (5log10r-5). The catalogue may be downloaded or queried using ADQL at various sites (see http://www.mpia.de/~calj/gedr3 distances.html) where it can also be cross-matched with the Gaia catalogue. Description: We have produced a catalogue of geometric distances for 1.47 billion stars and photogeometric distances for 92% of these. These estimates, and their uncertainties, can also be used as estimates of the distance modulus. Geometric distances use only the EDR3 parallaxes. Photogeometric distances additionally use the G magnitude and BP-RP colour from EDR3. Both types of estimate involve directiondependent priors constructed from a sophisticated model of the 3D distribution, colours, and magnitudes of stars in the Galaxy as seen by Gaia, i.e. accommodating both interstellar extinction and a Gaia selection function. Tests on mock data, but moreover validation against independent estimates and open clusters, suggest our estimates are reliable out to several kpc. For faint or more distant stars the prior will often dominate the estimates.