English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

CONTEXT. The Gaia Collaboration has used Gaia-DR2 sources withsix-dimensional (6D) phase space information to derive kinematical maps within5 kpc of the Sun, which is a reachable range for stars with relative error indistance lower than 20%.  AIMS. Here we aim to extend the range of distances by a factor of two tothree, thus adding the range of Galactocentric distances between 13 kpc and 20kpc to the previous maps, with their corresponding error and root mean squarevalues.  METHODS. We make use of the whole sample of stars of Gaia-DR2 includingradial velocity measurements, which consists in more than seven millionsources, and we apply a statistical deconvolution of the parallax errors basedon the Lucy's inversion method of the Fredholm integral equations of the firstkind, without assuming any prior.  RESULTS. The new extended maps provide lots of new and corroboratedinformation about the disk kinematics: significant departures of circularity inthe mean orbits with radial Galactocentric velocities between -20 and +20 km/sand vertical velocities between -10 and +10 km/s; variations of the azimuthalvelocity with position; asymmetries between the northern and the southernGalactic hemispheres, especially towards the anticenter that includes a largerazimuthal velocity in the south; and others.  CONCLUSIONS. These extended kinematical maps can be used to investigate thedifferent dynamical models of our Galaxy, and we will present our own analysesin the forthcoming second part of this paper. At present, it is evident thatthe Milky Way is far from a simple stationary configuration in rotationalequilibrium, but is characterized by streaming motions in all velocitycomponents with conspicuous velocity gradients.

Gaia-DR2 extended kinematical maps. Part I: Method and application