Identification and characterization of six spectroscopically confirmed massive protostructures at 2.5 < z < 4.5

We present six spectroscopically confirmed massive protostructures, spanning a redshift range of 2.5 < z < 4.5 in the Extended Chandra Deep Field South (ECDFS) field discovered as part of the Charting Cluster Construction in VUDS and ORELSE (C3VO) survey. We identify and characterize these remarkable systems by applying an overdensity measurement technique on an extensive data compilation of public and proprietary spectroscopic and photometric observations in this highly studied extragalactic field. Each of these six protostructures, i.e. a large scale overdensity (volume >9000 cMpc(3)) of more than 2.5 sigma(delta) above the field density levels at these redshifts, have a total mass Mtot >= 10(14.8) M-circle dot and one or more highly overdense (overdensity > 5 sigma(delta) ) peaks. One of the most complex protostructures discovered is a massive (M-tot = 10(15.1)M(circle dot)) system at z similar to 3.47 that contains six peaks and 55 spectroscopic members. We also discover protostructures at z similar to 3.30 and z similar to 3.70 that appear to at least partially overlap on sky with the protostructure at z similar to 3.47, suggesting a possible connection. We additionally report on the discovery of three massive protostructures at z = 2.67, 2.80, and 4.14 and discuss their properties. Finally, we discuss the relationship between star formation rate and environment in the richest of these protostructures, finding an enhancement of star formation activity in the densest regions. The diversity of the protostructures reported here provide an opportunity to study the complex effects of dense environments on galaxy evolution over a large redshift range in the early Universe.