Substructure, supernovae, and time resolved star formation history for
  Upper Scorpius
  The improved astrometry precision of Gaia-eDR3 allows us to perform a
detailed study of the Upper Scorpius OB association and revisit its kinematic,
spatial, and age substructure. We achieve this by combining the Convergent
Point method with clustering techniques, complementing with age estimations
based on Gaia photometry. We obtain a set of 4028 candidate members for Upper
Scorpius with completeness $\sim$99\% and contamination $\sim$11\%, extending
the current census with Gaia by at least $\sim$9\%. We extract an
astrometrically clean sample of 3114 sources with contamination $\sim$6\%. We
show that Upper Scorpius can be divided into at least 3 main kinematic groups.
We systematically investigate and characterize the Upper Scorpius' internal
structure, revealing that at least $\sim 34\%$ of its stellar populations are
contained in 7 spatial substructures, with well defined boundaries, kinematics
and relative ages, with suggested names: $\pi$ Scorpii (20 $^{\pm2}_{\pm1}$
Myr), $\alpha$ Scorpii (14$^{\pm2}_{\pm1}$ Myr), $\delta$ Scorpii
(9$^{\pm2}_{\pm1}$ Myr), $\beta$ Scorpii (8$^{\pm1}_{\pm1}$ Myr), $\omega$
Scorpii (8$^{\pm1}_{\pm1}$ Myr), $\nu$ Scorpii (7$^{\pm1}_{\pm1}$ Myr), after
their brightest member, and the well known $\rho$ Ophiuchi (4$^{\pm1}_{\pm1}$
Myr). We find a clear correlation in (1) density-age suggesting that these
substructures are expanding at a measurable rate, and (2) tangential
velocity-age, providing constrains on the dynamics of these substructures, and
the position of potential past triggering events. We estimate the time at which
4 potential supernovae events occurred in Upper Scorpius. Based on these
findings, we suggest a star formation scenario for Upper Scorpius with
unprecedented temporal resolution.
