An interferometric study of the HH288 molecular outflow

We present an interferometric study of the CO J = 1 --> 0 line emission in the HH288 molecular out ow. The IRAM Plateau de Bure interferometer was use d to obtain an 11-field mosaic covering the whole ow (similar to2 pc) with an angular resolution of about 3.5 " (7000 AU at a distance of 2 kpc). The data were complemented with short-spacings derived from IRAM 30-m observati ons. The exciting source of HH288, IRAS 00342+6347, is a young (dynamical a ge of the outflow similar or equal to a few 10(4) years) intermediate-mass (bolometric luminosity similar or equal to 500 L-circle dot, envelope mass similar or equal to6 to 30 M-circle dot) embedded protostar. This source is likely to be an intermediate-mass counterpart of a classical Class 0 low-m ass protostar. HH288 is actually a quadrupolar out ow, and the angular reso lution provided by the interferometric observations allows us to rule out m odels involving limb-brightened walls of a wide-angle single ow to explain such a morphology. The presence of two protostars in the central condensati on is the most appealing explanation to account for the presence of the two flows. While the small East-West ow has a quite simple morphology and kine matics, the large North-South ow includes several overlapping structures, c reated by successive ejection events. Large collimated limb-brightened cavi ties are observed, with high-velocity material located along or near the ow axis. The internal structure of HH288, including morphological coincidence between the CO and H-2 emission, supports prompt entrainment at the head o f large bow-shocks as the main formation process of molecular outflows from intermediate-mass protostars.