The Gaia space mission from the European Space Agency provides astrometric measurements for billions of stars in the Milky Way ushering in a new era of Galactic astronomy. However, most studies are limited by distance uncertainties, since parallax measurements beyond a few kpc distance from the Sun become increasingly challenging. We developed a new data-driven model to estimate the distances of luminous red giant stars from their spectroscopic and photometric features, which allowed us to make beautiful global maps (like the one shown on the left) over vast areas of our Galaxy. Using these distances we determined the circular velocity of the Milky Way out to 25 kpc by means of a Jeans model, which provides important constraints on the mass distribution of the Milky Way and the local dark matter density. Furthemore, we found that the mean Galactocentric radial velocities of these luminous red giant stars within the Galactic mid-plane reveal a kinematic spiral signature.
The Gaia space mission from the European Space Agency provides astrometric measurements for billions of stars in the Milky Way ushering in a new era of Galactic astronomy. However, most studies are limited by distance uncertainties, since parallax measurements beyond a few kpc distance from the Sun become increasingly challenging. We developed a new data-driven model to estimate the distances of luminous red giant stars from their spectroscopic and photometric features, which allowed us to make beautiful global maps (like the one shown on the left) over vast areas of our Galaxy. Using these distances we determined the circular velocity of the Milky Way out to 25 kpc by means of a Jeans model, which provides important constraints on the mass distribution of the Milky Way and the local dark matter density. Furthemore, we found that the mean Galactocentric radial velocities of these luminous red giant stars within the Galactic mid-plane reveal a kinematic spiral signature.