AzTEC 1.1 mm observations of high-z protocluster environments: SMG
  overdensities and misalignment between AGN jets and SMG distribution
  We present observations at 1.1 mm towards 16 powerful radio galaxies and a
radio-quiet quasar at 0.5<z<6.3 acquired with the AzTEC camera mounted at the
JCMT and ASTE to study the spatial distribution of submillimeter galaxies
towards possible protocluster regions. The survey covers a total area of 1.01
square degrees with rms depths of 0.52 - 1.44 mJy and detects 728 sources above
3sigma. We find overdensities of a factor of ~2 in the source counts of 3
individual fields (4C+23.56, PKS1138-262 and MRC0355-037) over areas of ~200 sq
deg. When combining all fields, the source-count analysis finds an overdensity
that reaches a factor $\gtrsim 3$ at S$_{\rm{1.1mm}} \ge 4$ mJy covering a
1.5-arcmin-radius area centred on the AGN. The large size of our maps allows us
to establish that beyond a radius of 1.5 arcmin, the radial surface density of
SMGs falls to that of a blank field. In addition, we find a trend for SMGs to
align closely to a perpendicular direction with respect to the radio jets of
the powerful central radio galaxies (73$_{+13}^{-14}$ degrees). This
misalignment is found over projected co-moving scales of 4-20 Mpc, departs from
perfect alignment (0 deg) by ~5sigma, and apparently has no dependence on SMG
luminosity. Under the assumption that the AzTEC sources are at the redshift of
the central radio galaxy, the misalignment reported here can be interpreted as
SMGs preferentially inhabiting mass-dominant filaments funneling material
towards the protoclusters, which are also the parent structures of the radio
galaxies.
