  The deposition of energy and momentum by supernova explosions has been
subject to numerous studies in the past few decades. However, while there has
been some work that focused on the transition from the adiabatic to the
radiative stage of a supernova remnant (SNR), the late radiative stage and
merging with the interstellar medium (ISM) have received little attention.
Here, we use three-dimensional, hydrodynamic simulations, focusing on the
evolution of SNRs during the radiative phase, considering a wide range of
physical explosion parameters ($n_{\text{H, ISM}} \in \left[0.1, 100\right]
\text{cm}^{-3}$ and $E_{\text{SN}} \in \left[1, 14\right]\times 10^{51}
\text{erg}$). We find that the radiative phase can be subdivided in four
stages: A pressure driven snowplow phase during which the hot overpressurized
bubble gas is evacuated and pushed into the cold shell, a momentum conserving
snowplow phase which is accompanied by a broadening of the shell, an implosion
phase where cold material from the back of the shell is flooding the central
vacuum and a final cloud phase, during which the imploding gas is settling as a
central, compact overdensity. The launching timescale for the implosion ranges
from a few 100 kyr to a few Myr, while the cloud formation timescale ranges
from a few to about 10 Myr. The highly chemically enriched clouds can become
massive ($M_{\text{cl}} \sim 10^3 - 10^4 \, \text{M}_{\odot}$) and
self-gravitating within a few Myr after their formation, providing an
attractive, novel pathway for supernova induced star and planet formation in
the ISM.
