Star formation

• Circumstellar disks
  

  High angular resolution ($\sim 2''$) images of a circumbinary disk around the young close binary GG Tau. The first image shows contours of the $^{13}$CO emission at 3 different velocities superimposed on a color image of the continuum emission. The continuum emission comes from a ring centered on the double-star. Blue-shifted gas (top) is seen on the left, while red-shifted gas (bottom) is seen on the right part of the dust ring, suggesting that the ring is rotating. The overall kinematic, and in particular the ``8'' shape of the gas emitting at the systemic velocity, agrees with Keplerian rotation around the binary star (Dutrey, Guilloteau and Simon, 1994 A&A 286, 149). The size of the dust ring is consistent with tidal truncation by the binary.

• High velocity outflows
  

  Montage of high resolution (3$''$) images of the high velocity outflow excited by the protostar L1448-mm in CO and SiO line emission. Blue and red contours show respectively the blue-shifted and redshifted gas along the edge of the outflow cavity, superimposed onto a lower resolution image from the 30-m (in color). Black countours indicate the SiO emission which concentrates along the axis of the outflow. Northward of the protostar, superposition of red and blueshifted CO emission indicates a collision between the main flow and second one created by another young star out of the field of view. See Bachiller et al. 1995 A&A 299, 875