From Giant H II regions and H II galaxies to globular clusters and
  compact dwarf ellipticals
  Massive starforming regions like Giant HII Regions (GHIIR) and HII Galaxies
(HIIG) are emission line systems ionized by compact young massive star clusters
(YMC) with masses ranging from $10^4$M$_\odot$ to $10^8$M$_\odot$. We model the
photometric and dynamical evolution over a Hubble time of the massive
gravitationally bound systems that populate the tight relation between absolute
blue magnitude and velocity dispersion ($M_{B}-\sigma$) of GHIIR and HIIG and
compare the resulting relation with that one of old stellar systems: globular
clusters, elliptical galaxies, bulges of spirals. After 12~Gyr of evolution
their position on the $\sigma$ vs. M$_B$ plane coincides -- depending on the
initial mass -- either with the globular clusters for systems with initial mass
$M < 10^6$M$_\odot$ or with a continuation of the ellipticals, bulges of
spirals and ultracompact dwarfs for YMC with $M >10^6$M$_\odot$. The slope
change in the $M_{B}-\sigma$ and $M_B$-size relations at cluster masses around
$10^6$M$_\odot$ is due to the larger impact of the dynamical evolution on the
lower mass clusters. We interpret our result as an indication that the YMC that
ionize GHIIR and HIIG can evolve to form globular clusters and ultra compact
dwarf ellipticals in about 12 Gyr so that present day globular clusters and
ultra compact dwarf ellipticals may have formed in conditions similar to those
observed in today GHIIR and HIIG.
