Millimeter and Radio Interferometry of Herbig Ae/Be Stars

Nine Herbig Ae/Be stars have been observed at λ = 2.7 mm with the IRAM and BIMA interferometers in order to place constraints on the presence of disk material around these objects. Only one Herbig Ae/Be star, Elias 3-1, was detected with certainty; two additional stars, MWC 137 and V645 Cyg, were possibly detected. The remaining six Herbig Ae/Be stars were not detected. Two deeply embedded objects near the target stars, LkHα 198-MM and V1318 Cyg S, were also detected. The emission from Elias 3-1 and V1318 Cyg S is unresolved, while that from LkHα 198 MM is resolved. Two stars (Elias 3-1 and V645 Cyg) were observed with the VLA at λ = 7 mm, 1.3 cm, and 3.6 cm. Based on our VLA data and those of Skinner, Brown, & Stewart, it appears that emission from ionized gas may contribute substantially to the millimeter emission from several sources. After correcting for this component where necessary, the remaining emission from most of the sample, attributed to dust, is considerably less than that predicted by assuming that the shorter wavelength emission arises in a disk. Much of the submillimeter and millimeter emission toward most of these stars must therefore arise in an extended envelope. For Elias 3-1, the data are consistent with a disk with mass around 0.1 M ☉ . We place limits on the masses of disks around the other stars.