Contact: MW-Gaia-HD[AT]zah.uni-heidelberg.deLocation: Virtual (hosted in Heidelberg, Germany)
The inner regions of our Milky Way are dominated by the Galactic bar and a classical bulge. The barred potential causes gas to flow inwards and form stars in the central few 100 parsecs. Over time this process may have built up the nuclear stellar disk, also found at these radii. At the very centre, the nuclear star cluster surrounds the Galactic supermassive black hole, Sgr A*. The larger inner bulge region also contains the highest-density parts of the Milky Way’s stellar halo, and perhaps an classical bulge component.
The next Gaia data release EDR3 will be released on Dec. 3, 2020, and will be based on 34 months of observations. Compared to DR2 improvements in completeness and astrometry (20% in parallaxes, factor of two in proper motion) will be provided. Additionally, more information on the parallax zero point will be included and the basis of the Celestial Reference Frame (CRF) will be extended to 1.5 million objects, a factor of three more.
During this 3 day workshop in (virtual) Heidelberg, we will focus on the impact of the ultra-precise Gaia astrometry on our understanding of the structure and dynamics of the Galactic bar and bulge region including the interrelation with the inner halo, the nuclear stellar disc and the central star cluster. Chemical enrichment, ages and the assembly history will also be covered. The celestial reference frame, zero points of parallaxes and proper motions, as well as questions of fundamental physics will be discussed. Also first results based on EDR3 are expected.
The format of the workshop is based on invited key presentations and contributed talks, ePosters, a practical hands-on session for EDR3, and dedicated discussions.
Topics Covered
Gaia EDR3: overview, completeness
Gaia Ref Frame: zero points in parallax and proper motion, fundamental physics and relativistic effects using Gaia and VLBI, Sgr A* and testing GR
Bulge, Bar and Inner Halo: kinematics, dynamics, mass distribution
Bulge, Bar, Inner Halo: metallicity-orbit distribution and stellar ages
Bulge, Bar, Inner Halo: critical discussion on stellar ages in Bulge, assembly history from (hydro-)dynamical and cosmological simulations
Nuclear Disk, Gas Inflow and Star Formation