We present Karl G Jansky Very Large Array (VLA) observations of CO(2-1) line
emission and rest-frame 250GHz continuum emission of the Hyper-Luminous IR
Galaxies (HyLIRGs) BRI1202-0725 (z=4.69) and BRI1335-0417 (z=4.41), with an
angular resolution as high as 0.15". Our low order CO observations delineate
the cool molecular gas, the fuel for star formation in the systems, in
unprecedented detail. For BRI1202-0725, line emission is seen from both extreme
starburst galaxies: the quasar host and the optically obscured submm galaxy
(SMG), in addition to one of the Lyman-alpha emitting galaxies in the group.
Line emission from the SMG shows an east-west extension of about 0.6". For
Lyalpha-2, the CO emission is detected at the same velocity as [CII] and [NII],
indicating a total gas mass ~4.0*10^10 solar masses. The CO emission from
BRI1335-0417 peaks at the nominal quasar position, with a prominent northern
extension (~1", a possible tidal feature). The gas depletion timescales are
~10^7 years for the three HyLIRGs, consistent with extreme starbursts, while
that of Lyalpha-2 may be consistent with main sequence galaxies. We interpret
these sources as major star formation episodes in the formation of massive
galaxies and supermassive black holes (SMBHs) via gas rich mergers in the early
Universe.G. C. J. is grateful for support from NRAO through the Grote Reber Doctoral Fellowship Program. R. G. M. acknowledges the UK Science and Technology Facilities Council (STFC). K. O. acknowledges the Kavli Institute Fellowship at the Kavli Institute for Cosmology in the University of Cambridge supported by the Kavli Foundation. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We thank all those involved in the VLA project for making these observations possible (project code 13A-012).This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by IOP Publishing
