Gaia Data Release 2: using Gaia parallaxes

Abstract

The second Gaia data release (GDR2) provides precise five-parameter astrometric data (positions, proper motions and parallaxes) for an unprecedented amount of sources (more than $1.3$ billion, mostly stars). The use of this wealth of astrometric data comes with a specific challenge: how does one properly infer from these data the astrophysical parameters of interest? The main - but not only - focus of this paper is the issue of the estimation of distances from parallaxes, possibly combined with other information. We start with a critical review of the methods traditionally used to obtain distances from parallaxes and their shortcomings. Then we provide guidelines on how to use parallaxes more efficiently to estimate distances by using Bayesian methods. In particular also we show that negative parallaxes, or parallaxes with relatively larger uncertainties still contain valuable information. Finally, we provide examples that show more generally how to use astrometric data for parameter estimation, including the combination of proper motions and parallaxes and the handling of covariances in the uncertainties. The paper contains examples based on simulated Gaia data to illustrate the problems and the solutions proposed. Furthermore, the developments and methods proposed in the paper are linked to a set of tutorials included in the Gaia archive documentation that provide practical examples and a good starting point for the application of the recommendations to actual problems. In all cases the source code for the analysis methods is provided. Our main recommendation is to always treat the derivation of (astro-) physical parameters from astrometric data, in particular when parallaxes are involved, as an inference problem which should preferably be handled with a full Bayesian approach.

arXiv commentAccepted for publication in the special issue "Gaia data release 2" of Astronomy & Astrophysics

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• The Planck Cold Clump G108.37-01.06: A Site of Complex Interplay between H II Regions, Young Clusters and Filaments
• A VLT/FLAMES survey for massive binaries in Westerlund 1 V. the X-ray selected blue stragglers Wd1-27 and -30a
• Galactic Calibration of the Tip of the Red Giant Branch
• The cosmic DANCe of Perseus I: Membership, phase-space structure, mass, and energy distributions
• Distance mapping applied to four well-known planetary nebulae and a nova shell
• Identifying Blue Large Amplitude Pulsators in the Galactic Plane using Gaia DR2: a case study
• An Updated Distance to the Cygnus Loop based on Gaia Early DR3
• Multiplicity of stars with planets in the solar neighbourhood
• High-speed stars. II. An unbound star, young stars, bulge metal-poor stars, and Aurora candidates
• Refining the origins of the gamma-ray binary 1FGL J1018.6-5856
• Rotation of Kepler field dwarfs and sub giants: Spectroscopic $v\sin I$ from APOGEE
• Towards a fully consistent Milky Way disk model -- IV. The impact of Gaia DR2 and APOGEE
• The Photo-Astrometric Vertical Tracer Density of the Milky Way II: Results from Gaia
• Ultracool dwarfs identified using spectra in LAMOST DR7
• From the stellar properties of HD219134 to the internal compositions of its transiting exoplanets
• Evidence of dust grain evolution from extinction mapping in the IC 63 photodissociation region
• On the Galactic rotation curve inferred from the Jeans equations Assessing its robustness using Gaia DR3 and cosmological simulations
• Hubble distancing: Focusing on distance measurements in cosmology
• The relation of the Alpha Persei star cluster with the nearby stellar stream
• Photometric Flaring Fraction of M dwarf Stars from the SkyMapper Southern Survey
• The first heavy-metal hot subdwarf composite binary SB 744
• S and VV Corona Australis: Spectroscopic Variability in Two Young Binary Star Systems
• Orbital and atmospheric parameters of two wide O-type subdwarf binaries: BD$-$11${}^{\mathrm{o}}$162 and Feige 80
• Distance scale for high-luminosity stars in OB associations and in field with Gaia DR2. Spurious systematic motions
• Robust diffraction-limited NIR-to-NUV wide-field imaging from stratospheric balloon-borne platforms -- SuperBIT science telescope commissioning flight & performance
• First detection of oscillations in the Halo giant HD 122563: validation of seismic scaling relations and new fundamental parameters
• Angular Sizes and Effective Temperatures of O-type Stars from Optical Interferometry with the CHARA Array
• Apsidal motion and physical parameters in the eclipsing system V490 Sct
• Young nearby open clusters and their luminosity functions
• VLTI-GRAVITY measurements of cool evolved stars: I. Variable photosphere and extended atmosphere of the Mira star R Peg
• Another super-dense sub-Neptune in K2-182 b and refined mass measurements for K2-199 b and c
• A hyper-runaway white dwarf in Gaia DR2 as a Type Iax supernova primary remnant candidate
• Cataclysmic variables around the period-bounce: An eROSITA-enhanced multi-wavelength catalog
• The historical record of massive star formation in Cygnus
• Hen 3-860: New southern eclipsing symbiotic star observed in the outburst
• Toward a Larger Sample of Radio Jets from Quiescent Black Hole X-ray Binaries
• Extremely precise age and metallicity of the open cluster NGC 2506 using detached eclipsing binaries
• Photometric study of the young open clusters IC 1442, King 21, and Trumpler 7
• Three-dimensional magnetic fields of molecular clouds
• First assessment of the binary lens OGLE-2015_BLG-0232
• Long-term X-ray Variability of the Symbiotic System RT Cru based on Chandra Spectroscopy
• Star formation in IC1396: Kinematics and subcluster structure revealed by Gaia
• Neutron-capture elements in dwarf galaxies III: A homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies
• System parameters of three short period cataclysmic variable stars
• The disruption of the low-mass globular cluster E3
• Exploring the structure and kinematics of the Milky Way through A stars
• The Time-Domain Spectroscopic Survey: Radial Velocity Variability in Dwarf Carbon Stars
• Inhomogeneity in the early Galactic chemical enrichment exposed by beryllium abundances in extremely metal-poor stars
• Applying Noether's theorem to matter in the Milky Way: evidence for external perturbations and non-steady-state effects from Gaia Data Release 2
• Observing the Galactic Underworld: Predicting photometry and astrometry from compact remnant microlensing events
• M Subdwarf Research. II. Atmospheric Parameters and Kinematics
• Blanco DECam Bulge Survey (BDBS) V. Cleaning the foreground populations from Galactic bulge colour-magnitude diagrams using Gaia EDR3
• Light propagation in 2PN approximation in the field of one moving monopole II. Boundary value problem
• The period-gap cataclysmic variable CzeV404 Her: A link between SW Sex and SU UMa systems
• Kinematics of the Milky Way from the Gaia EDR3 red giants and sub-giants
• The nature of the symbiotic candidate 2MASS J07363415+6538548 in the field of NGC 2403
• Revising Properties of Planet-host Binary Systems I.: Methods and Pilot Study
• Optical Linear Polarization toward the Open Star Cluster Casado Alessi 1
• First Results from MFOSC-P : Low Resolution Optical Spectroscopy of a Sample of M dwarfs within 100 parsecs
• A Low-Mass Pre-Main-Sequence Eclipsing Binary in Lower Centaurus Crux Discovered with TESS
• Detailed analysis of the poorly studied northern open cluster NGC 1348 using multi-color photometry and GAIA EDR3 astrometry
• Cluster membership for the long period Cepheid calibrator SV Vul
• Dust in the Wolf-Rayet Nebula M1-67
• Mapping circumstellar magnetic fields of late-type evolved stars with the Goldreich-Kylafis effect: CARMA observations at $\lambda 1.3$ mm of R Crt and R Leo
• Validation of HD 183579b using archival radial velocities: a warm-neptune orbiting a bright solar analog
• The Alma catalogue of OB stars. III. A cross-match with Gaia DR3 and an extension based on new spectral classifications
• The Gaia/IPHAS and Gaia/KIS Value-Added Catalogues
• Orbits and masses of binaries from Speckle Interferometry at SOAR
• GK Car and GZ Nor: Two low-luminous, depleted RV Tauri stars
• Two New White Dwarfs With Variable Magnetic Balmer Emission Lines
• The extreme O-type spectroscopic binary HD 93129A
• A spectroscopic follow-up for Gaia19bld
• THA 15-31: Discovery with VLT/X-Shooter and Swift/UVOT of a new symbiotic star of the accreting-only variety
• OGLE-2018-BLG-1269Lb: A Jovian Planet With A Bright, $I=16$ Host
• Distribution of red clump stars does not support the X-shaped Galactic bulge
• Exploring Galactic open clusters with Gaia I. An examination in the first kiloparsec
• Back to "Normal" for the Disintegrating Planet Candidate KIC 12557548 b
• Analysis of spiral structure in the accretion disc of the novalike Cataclysmic Variable EC21178--5417
• Constraining stellar parameters and atmospheric dynamics of the carbon AGB star V Oph
• BRITE photometry of the massive post-RLOF system HD149404
• The multi-planet system TOI-421 -- A warm Neptune and a super puffy mini-Neptune transiting a G9 V star in a visual binary
• Wide companions to M and L subdwarfs with Gaia and the Virtual Observatory
• The planetary nebula IC 5148 and its ionized halo
• FUSE Spectroscopic Analysis of the Slowest Symbiotic Nova AG Peg During Quiescence
• A New Transition Wolf-Rayet WN/C Star in the Milky Way
• Benfords law in the Gaia universe
• Identification of new hot subdwarf binary systems by means of Virtual Observatory tools
• The Photo-Astrometric Vertical Tracer Density of the Milky Way I: The Method
• Element abundance analysis of the metal-rich stellar halo and high-velocitythick disk in the galaxy
• K2-280b -- a low density warm sub-Saturn around a mildly evolved star
• A hierarchical Bayesian model to infer PL(Z) relations using Gaia parallaxes
• The independent discovery of planet candidates around low mass stars and astrophysical false positives from the first two TESS sectors
• VVV survey near-infrared colour catalogue of known variable stars
• Kepler-62f: Kepler's First Small Planet in the Habitable Zone, but Is It Real?
• Probing Axial Symmetry Breaking in the Galaxy with Gaia Data Release 2
• Dust emission, extinction, and scattering in LDN 1642
• Reconciling the predictions of microlensing analysis with radial velocity measurements for OGLE-2011-BLG-0417
• White Dwarf Photospheric Abundances in Cataclysmic Variables: I. SS Aurigae and TU Mensae
• Existence of the Metal-Rich Stellar Halo and High-velocity Thick Disk in the Galaxy
• An observational testbed for cosmological zoom-in simulations: constraining stellar migration in the solar cylinder using asteroseismology
• Properties of a hypothetical cold pulsar wind in LS~5039
• Nearby open clusters with tidal features: golden sample selection and 3D structure
• A study of accretion and disk diagnostics in the NGC 2264 cluster
• Multi-wavelength observations and modelling of a quiescent cloud LDN1512
• A massive open cluster hiding in full sight
• Resolving the circumstellar environment of the Galactic B[e] supergiant star MWC 137. II. Nebular kinematics and stellar variability
• Evidence for the First Extragalactic Hydrogen Recombination Line Maser in NGC 253
• Solving the distance discrepancy for the open cluster NGC 2453. The planetary nebula NGC 2452 is not a cluster member
• Two substructures in the nearby stellar halo found in Gaia and RAVE
• White Dwarf Photospheric Abundances in Cataclysmic Variables -- II. White Dwarfs With and Without a Mask
• Discovery and Characterization of a Rare Magnetic Hybrid $\beta$ Cephei Slowly Pulsating B-type Star in an Eclipsing Binary in the Young Open Cluster NGC 6193
• News from Gaia on sigma Ori E: a case study for the wind magnetic braking process
• Modeling of two CoRoT solar analogues constrained by seismic and spectroscopic analysis
• Discovering new B[e] supergiants and candidate Luminous Blue Variables in nearby galaxies
• The distribution, kinematics and luminosities of extreme helium stars as probes of their origin and evolution
• The oldest stars with low neutron-capture element abundances and origins in ancient dwarf galaxies
• GaiaUnlimited: The old stellar disc of the Milky Way as traced by the Red Clump
• The Eclipsing Binaries via Artificial Intelligence. II. Need for Speed in PHOEBE Forward Models
• A detection of the layered structure of nearby open clusters
• Investigating kinematics and dynamics of three open clusters towards Galactic anti-center
• J-PLUS: Discovery and characterisation of ultracool dwarfs using Virtual Observatory tools II. Second data release and machine learning methodology
• A Gaia based photometric and kinematic analysis of the old open cluster King 11
• GG Carinae: orbital parameters and accretion indicators from phase-resolved spectroscopy and photometry
• KIC 2568888: To be or not to be a binary
• Astronomical distance scales in the Gaia era
• Understanding the rotational variability of K2 targets. HgMn star KIC 250152017 and blue horizontal branch star KIC 249660366
• A systematic study of spiral density waves in the accretion discs of Cataclysmic Variables
• Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391
• J-PLUS: Discovery and characterisation of ultracool dwarfs using Virtual Observatory tools
• HST FUV spectroscopy of the short orbital period recurrent nova CI Aql: Implications for white dwarf mass evolution
• HD 7977 and its possible influence on Solar System bodies
• High-resolution spectroscopic study of dwarf stars in the northern sky: Na to Zn abundances in two fields with radii of 20 degrees
• Star cluster survival in dark matter halos: An old cluster in Eridanus II?
• Sustaining Star Formation in the Galactic Star Cluster M 36?
• Benchmarking the effective temperature scale of red giant branch stellar models: the case of the metal-poor halo giant HD 122563
• Tracing the magnetic field morphology of the LDN 1172/1174 cloud complex
• A revised view of the Canis Major stellar overdensity with DECam and Gaia: new evidence of a stellar warp of blue stars
• A revisit to the enigmatic variable star 21 Comae
• Kinematics of Type II Cepheids of the Galactic Halo
• Exploration of morphological coherence in open clusters with a "core-shell'' structure
• The Heating and Pulsations of V386 Serpentis after its 2019 Dwarf Nova Outburst
• Third Nearest WZ Sge-Type Dwarf Nova candidate ASASSN-14dx Classified on the Basis of Gaia Data Release 2
• Miec: A Bayesian hierarchical model for the analysis of nearby young open clusters
• Followup ground-based observations of the dwarf nova KZ Gem
• High-Resolution Radio Observations of Five Optically Selected Type 2 Quasars
• Red Be stars in the Magellanic Clouds?
• X-Ray Redshifts of Obscured Chandra Source Catalog AGN
• Characterizing the Evolved Stellar Population in the Galactic Foreground I: Bolometric Magnitudes, Spatial Distribution and P-L Relations
• CN and CO Features: Key Indicators of Red Giant Evolutionary Phase in Moderate-Resolution X-Shooter Spectra
• Two New Rapidly-Rotating ON Stars Found With LAMOST
• Characterisation of the X-ray point source variability in the eROSITA south ecliptic pole field
• New Symbiotic Stars from LAMOST DR10 Spectra and Multi-band Photometry
• A study of full space motions of outer Galactic disk A and F stars in two deep pencil-beams
• Hunting white dwarfs at the center of planetary nebulae
• The H$\alpha$ line emission of the Be star $\beta$ Psc: the last 40 years
• Kinematic distinction of the two subpopulations of X-ray pulsars
• Census of young stellar population in the Galactic H II region Sh2-242
• Runaway blue main-sequence stars at high Galactic latitudes. Target selection with Gaia and spectroscopic identification
• Fast quasi-periodic oscillations in the eclipsing polar VV Puppis from VLT and XMM-Newton observations
• Line-of-sight mass estimator and the masses of the Milky Way and Andromeda Galaxy
• A joint 1% calibration of the RR Lyrae & type-II Cepheid Leavitt laws yields homogeneous distances to 93 Galactic globular clusters
• A high stellar multiplicity rate amongst TESS planet candidates in the Neptunian desert using Gaia DR3 astrometry
• The VMC Survey -- LIV. Anomalous Cepheids in the Magellanic Clouds Period-Luminosity relations in the near-infrared bands
• ACRONYM IV: Three New, Young, Low-mass Spectroscopic Binaries
• A sub-Neptune transiting the young field star HD 18599 at 40 pc
• Constraining H0 Via Extragalactic Parallax
• Concerning the occurrence of bow shocks around high-mass X-ray binaries
• Transient behavior of three SU UMa-type dwarf novae; AR Pic, QW Ser and V521 Peg
• A hundred new eclipsing binary system candidates studied in a near-infrared window in the VVV survey
• M-dwarf stars in the b294 field from the VISTA Variables in the Vía Láctea (VVV)
• Asteroseismology of sz lyn using multi-band high time resolution photometry from ground and space
• Kinematic identification of young nearby moving groups from a sample of chromospherically active stars in the RAVE catalog
• Searching for Low-mass Population III Stars Disguised as White Dwarfs
• Collision of Two Stellar Associations in the Nearby Gum Nebula
• Signatures of the Galactic bar in high-order moments of proper motions measured by Gaia
• Accretion in low-mass members of the Orion Nebula Cluster with young transition disks
• Radial velocities from far red spectra of Carina Arm O and early B stars
• The hydrogen Balmer lines and jump in absorption in accretion disc modeling -- an ultraviolet-optical spectral analysis of the dwarf novae UZ Serpentis and CY Lyrae
• Calibration of the [C/N] and [Y/Mg] chemical clocks with asteroseismic ages from the TESS space mission
• Massive Stars in Molecular Clouds Rich in High-energy Sources: The Bridge of G332.809-0.132 and CS 78 in NGC 6334
• Features of the Residual Velocity Ellipsoid of Hot Subdwarfs from the Gaia DR2 Catalog
• On Neutron Star Natal Kicks in High-Mass X-Ray Binaries: Insights from Population Synthesis
• Clustered star formation towards Berkeley 87 / ON2. I. Multi-wavelength census and the population overlap problem
• High reddening patches in Gaia DR2. Possible artifacts or indication of star formation at the edge of the Galactic disk
• Hidden power of near-infrared data for the study of young clusters: Illustrative case of RCW 38
• XGAPS: a sub-arcsecond cross-match of Galactic Plane Surveys
• 200,000+ Deep Learning-inferred Periods of Stellar Variability from the All-Sky Automated Survey for Supernovae
• The Occurrence-weighted Median Planets Discovered by Transit Surveys Orbiting Solar-type Stars and Their Implications for Planet Formation and Evolution
• Inferring properties of the local white dwarf population in astrometric and photometric surveys
• A Cartesian catalog of 30 million Gaia sources based on second-order and Monte Carlo error propagation
• A revised comparison of distant and nearby solar twins
• Joint Survey Processing II: Stellar Proper Motions in the COSMOS Field, from Hubble Space Telescope ACS and Subaru Telescope HSC Observations
• A comparative study of O, Ne, Cl, and Ar in Hii regions and PNe of the Galactic disk: Temporal evolution of radial gradients?
• Distance and extinction to the Milky Way spiral arms along the Galactic centre line of sight
• Spatially Dependent Photometric Activity of M dwarfs in the Solar Cylinder
• Large Interstellar Polarisation Survey. III. Observational constraints on the structure of grains
• Dynamical Models of the Milky Way in Action Space with LAMOST DR8 and GAIA EDR3
• Multi-tracer analysis of straight depolarisation canals in the surroundings of the 3C 196 field
• Cloud G074.11+00.11: a stellar cluster in formation
• Kinematics of the Milky way from the statistical analysis of the Gaia Data Release 3
• Characterization of the Visual Binary TOI-6883AB and its dynamical implications for the planetary companion TOI-6883Ab
• Dwarfs or giants? Stellar metallicities and distances in the Canada-France-Imaging-Survey from $ugrizG$ multi-band photometry
• Blending from binarity in microlensing searches toward the Large Magellanic Cloud
• The morphological stability of open clusters: a new 2D perspective
• Trigonometric parallaxes of two T dwarfs with Keck and ShaneAO astrometry