  We present ALMA 870 micron (345 GHz) data for 49 high redshift (0.47<z<2.85),
luminous (11.7 < log L(bol) (Lsun) < 14.2) radio-powerful AGN, obtained to
constrain cool dust emission from starbursts concurrent with highly obscured
radiative-mode black hole (BH) accretion in massive galaxies which possess a
small radio jet. The sample was selected from WISE with extremely steep (red)
mid-infrared (MIR) colors and with compact radio emission from NVSS/FIRST.
Twenty-six sources are detected at 870 microns, and we find that the sample has
large mid- to far-infrared luminosity ratios consistent with a dominant and
highly obscured quasar. The rest-frame 3 GHz radio powers are 24.7 < log P3.0
GHz (W/Hz) < 27.3, and all sources are radio-intermediate or radio-loud. BH
mass estimates are 7.7 < log M(BH) (Msun) < 10.2. The rest frame 1-5 um SEDs
are very similar to the "Hot DOGs" (Hot Dust Obscured Galaxies), and steeper
(redder) than almost any other known extragalactic sources. ISM masses
estimated for the ALMA detected sources are 9.9 < log M(ISM) (Msun) < 11.75
assuming a dust temperature of 30K. The cool dust emission is consistent with
star formation rates (SFRs) reaching several thousand Msun/yr, depending on the
assumed dust temperature, however we cannot rule out the alternative that the
AGN powers all the emission in some cases. Our best constrained source has
radiative transfer solutions with ~ equal contributions from an obscured AGN
and a young (10-15 Myr) compact starburst.
