Galactic spiral structure revealed by Gaia EDR3

Vol. 651
5. Galactic structure, stellar clusters and populations

Galactic spiral structure revealed by Gaia EDR3

by E. Poggio, R. Drimmel, T. Cantat-Gaudin, et al. 2021, A&A, 651, A104

Poggio and collaborators use Gaia Early Data Release 3 (EDR3) to map the density variations in the distribution of young stars, open clusters, and classical Cepheids in the Galactic disk. Using kernel density and wavelet techniques, they construct an over-density map exhibiting large-scale arches that extend in a clumpy but coherent way over the entire sampled volume, indicating the location of the spiral arm segments in the vicinity of the Sun. The new map is generally consistent with previous models of the Sagittarius-Carina spiral arm. However, it differs significantly for the arms in quadrant III (galactic longitudes 180° < l < 270°).