ESA Hubble Science Release | Gaia | 2017 Nov 27
[img3="Credit: ESA/Hubble, Digitized Sky Survey 2"]https://cdn.spacetelescope.org/archives ... c1719e.jpg[/img3][hr][/hr]A team of astronomers used data from both the NASA/ESA Hubble Space Telescope and ESA’s Gaia satellite to directly measure the 3D motions of individual stars in a nearby galaxy. The achieved accuracy is better than anything previously measured for a galaxy beyond the Milky Way. The motions provide a field test of the currently-accepted cosmological model and also measure the trajectory of the galaxy through space. ...
Only by combining the datasets from these two successful ESA missions — produced more than 12 years apart — could the scientists directly measure the exact 3D motions of stars within the Sculptor Dwarf Galaxy [1]. The is the first time this has been achieved with such accuracy for a galaxy other than the Milky Way [2]. ...
The Sculptor Dwarf Galaxy is a dwarf spheroidal galaxy, which are among the most dark matter dominated objects in the Universe. This makes them ideal targets for investigating the properties of dark matter. In particular, understanding how dark matter is distributed in these dwarf galaxies allows astronomers to test the validity of the currently-accepted cosmological model. However, dark matter cannot be studied directly. ...
Stellar Motions in Nearby Galaxy Hint at Underlying Dark Matter
ESA | Science & Technology | Gaia | 2017 Nov 27
By pinning down, for the first time, the three-dimensional motions of individual stars in the nearby Sculptor dwarf galaxy, astronomers have shed new light on the distribution of invisible dark matter that pervades the galaxy. This study combined the positions of stars measured by ESA's Gaia mission with observations from the NASA/ESA Hubble Space Telescope taken twelve years earlier. ...
Three-Dimensional Motions in the Sculptor Dwarf Galaxy as a Glimpse of a New Era - D. Massari et al
- Nature Astronomy (online 27 Nov 2017) DOI: 10.1038/s41550-017-0322-y
arXiv.org > astro-ph > arXiv:1711.08945 > 24 Nov 2017