Far-infrared Photometry of Low-mass Pre-main-sequence Stars with Broad CO Wings

A sample of 14 low-mass premain-sequence stars were studied in the far-infrared. There is evidence for outflowing material around twelve of these stars; in most cases the evidence includes broad wings on the profiles of the CO J=2 to 1 line. Ten of the objects were detected ( 5 sigma) at 100 micro, and seven were mapped at 50 and 100 micro. The far-infrared emission makes a significant contribution to the total luminosity of the objects. It is found that the force available from radiation pressure is not sufficient to drive the outflows. Any process which taps the same energy source as does the present stellar luminosity must have high efficiency.