Search Publications
The Gaia mission
Prusti, T.; Mazeh, T.; Zucker, S. +623 more
Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific …
Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
Prusti, T.; Mazeh, T.; Zucker, S. +589 more
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims: A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitat…
Gaia Data Release 1. Astrometry: one billion positions, two million proper motions and parallaxes
Mora, A.; Jordan, S.; Figueras, F. +80 more
Context. Gaia Data Release 1 (DR1) contains astrometric results for more than 1 billion stars brighter than magnitude 20.7 based on observations collected by the Gaia satellite during the first 14 months of its operational phase.
Aims: We give a brief overview of the astrometric content of the data release and of the model assumptions, data p…
On Galactic Density Modeling in the Presence of Dust Extinction
Bovy, Jo; Rix, Hans-Walter; Finkbeiner, Douglas P. +2 more
Inferences about the spatial density or phase-space structure of stellar populations in the Milky Way require a precise determination of the effective survey volume. The volume observed by surveys such as Gaia or near-infrared spectroscopic surveys, which have good coverage of the Galactic midplane region, is highly complex because of the abundant…
Eclipsing Binaries as Benchmarks for Trigonometric Parallaxes in the Gaia Era
Torres, Guillermo; Stassun, Keivan G.
We present fits to the broadband photometric spectral energy distributions (SEDs) of 158 eclipsing binaries (EBs) in the Tycho-2 catalog. These EBs were selected because they have highly precise stellar radii, effective temperatures, and in many cases metallicities previously determined in the literature, and thus have bolometric luminosities that…
The Shape of the Inner Milky Way Halo from Observations of the Pal 5 and GD--1 Stellar Streams
Bovy, Jo; Kallivayalil, Nitya; Fritz, Tobias K. +1 more
We constrain the shape of the Milky Way’s halo by dynamical modeling of the observed phase-space tracks of the Pal 5 and GD-1 tidal streams. We find that the only information about the potential gleaned from the tracks of these streams are precise measurements of the shape of the gravitational potential—the ratio of vertical to radial acceleration…
The Coupled Physical Structure of Gas and Dust in the IM Lup Protoplanetary Disk
Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +4 more
The spatial distribution of gas and solids in protoplanetary disks determines the composition and formation efficiency of planetary systems. A number of disks show starkly different distributions for the gas and small grains compared to millimeter-centimeter-sized dust. We present new Atacama Large Millimeter/Submillimeter Array observations of th…
Black hole, neutron star and white dwarf candidates from microlensing with OGLE-III
Soszyński, I.; Udalski, A.; Szymański, M. K. +13 more
Most stellar remnants so far have been found in binary systems, where they interact with matter from their companions. Isolated neutron stars and black holes are difficult to find as they are dark, yet they are predicted to exist in our Galaxy in vast numbers. We explored the OGLE-III data base of 150 million objects observed in years 2001-2009 an…
Estimating Distances from Parallaxes. II. Performance of Bayesian Distance Estimators on a Gaia-like Catalogue
Bailer-Jones, Coryn A. L.; Astraatmadja, Tri L.
Estimating a distance by inverting a parallax is only valid in the absence of noise. As most stars in the Gaia catalog will have non-negligible fractional parallax errors, we must treat distance estimation as a constrained inference problem. Here we investigate the performance of various priors for estimating distances, using a simulated Gaia cata…
Estimating Distances from Parallaxes. III. Distances of Two Million Stars in the Gaia DR1 Catalogue
Bailer-Jones, Coryn A. L.; Astraatmadja, Tri L.
We infer distances and their asymmetric uncertainties for two million stars using the parallaxes published in the Gaia DR1 (GDR1) catalogue. We do this with two distance priors: A minimalist, isotropic prior assuming an exponentially decreasing space density with increasing distance, and an anisotropic prior derived from the observability of stars…