ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP) II. Survey
  overview: a first look at 1.3 mm continuum maps and molecular outflows
  Planck Galactic Cold Clumps (PGCCs) are contemplated to be the ideal targets
to probe the early phases of star formation. We have conducted a survey of 72
young dense cores inside PGCCs in the Orion complex with the Atacama Large
Millimeter/submillimeter Array (ALMA) at 1.3\,mm (band 6) using three different
configurations (resolutions $\sim$ 0$\farcs$35, 1$\farcs$0, and 7$\farcs$0) to
statistically investigate their evolutionary stages and sub-structures. We have
obtained images of the 1.3\,mm continuum and molecular line emission
($^{12}$CO, and SiO) at an angular resolution of $\sim$ 0$\farcs$35 ($\sim$
140\,au) with the combined arrays. We find 70 substructures within 48 detected
dense cores with median dust-mass $\sim$ 0.093\,M$_{\sun}$ and deconvolved size
$\sim$ 0$\farcs$27. Dense substructures are clearly detected within the central
1000\,au of four candidate prestellar cores. The sizes and masses of the
substructures in continuum emission are found to be significantly reduced with
protostellar evolution from Class\,0 to Class\,I. We also study the
evolutionary change in the outflow characteristics through the course of
protostellar mass accretion. A total of 37 sources exhibit CO outflows, and 20
($>$50\%) show high-velocity jets in SiO. The CO velocity-extents ($\Delta$Vs)
span from 4 to 110 km/s with outflow cavity opening angle width at 400\,au
ranging from $[\Theta_{obs}]_{400}$ $\sim$ 0$\farcs$6 to 3$\farcs$9, which
corresponds to 33$\fdg$4$-$125$\fdg$7. For the majority of the outflow sources,
the $\Delta$Vs show a positive correlation with $[\Theta_{obs}]_{400}$,
suggesting that as protostars undergo gravitational collapse, the cavity
opening of a protostellar outflow widens and the protostars possibly generate
more energetic outflows.
