The ALMA Early Science view of FUor/EXor objects. I. Through the
  looking-glass of V2775 Ori
  As part of an ALMA survey to study the origin of episodic accretion in young
eruptive variables, we have observed the circumstellar environment of the star
V2775 Ori. This object is a very young, pre-main sequence object which displays
a large amplitude outburst characteristic of the FUor class. We present Cycle-2
band 6 observations of V2775 Ori with a continuum and CO (2-1) isotopologue
resolution of 0.25\as (103 au). We report the detection of a marginally
resolved circumstellar disc in the ALMA continuum with an integrated flux of
$106 \pm 2$ mJy, characteristic radius of $\sim$ 30 au, inclination of
$14.0^{+7.8}_{-14.5}$ deg, and is oriented nearly face-on with respect to the
plane of the sky.
  The \co~emission is separated into distinct blue and red-shifted regions that
appear to be rings or shells of expanding material from quasi-episodic
outbursts. The system is oriented in such a way that the disc is seen through
the outflow remnant of V2775 Ori, which has an axis along our line-of-sight.
The $^{13}$CO emission displays similar structure to that of the \co, while the
C$^{18}$O line emission is very weak. We calculated the expansion velocities of
the low- and medium-density material with respect to the disc to be of -2.85 km
s$^{-1}$ (blue), 4.4 km s$^{-1}$ (red) and -1.35 and 1.15 km s$^{-1}$ (for blue
and red) and we derived the mass, momentum and kinetic energy of the expanding
gas. The outflow has an hourglass shape where the cavities are not seen. We
interpret the shapes that the gas traces as cavities excavated by an ancient
outflow. We report a detection of line emission from the circumstellar disc and
derive a lower limit of the gas mass of 3 \MJup.
