Wind diagnostics and correlations with the near-infrared excess in Herbig Ae/Be stars

Intermediate dispersion spectroscopic observations of 37 Herbig Ae/Be stars reveal that the equivalent widths of their [OI]λ6300 andHα emission lines, are related to their nearinfrared colours in the same fashion as the T-Tauri stars. Such a correlation strongly supports the idea that the winds from Herbig Ae/Be stars arise in the same manner as those from TTauri stars, i.e. through accretion driven mass-loss. We also find that the [OI]λ6300 line luminosity correlates better with excess infrared luminosity than with stellar luminosities, again supporting the idea that Herbig Ae/Be winds are accretion driven. If one includes the lower mass analogues of the Herbig Ae/Be starswith forbidden line emission, i.e. the classical T-Tauri stars, the correlation betweenmass-loss rate and infrared excess spans 5 orders of magnitude in luminosity and a range of masses from 0.5M to approximately 10M . Our observations therefore extend the findings of Cohen et al. (1989) and Cabrit et al. (1990) for low mass young stars and, taken in conjunction with other evidence (Corcoran &Ray 1997), strongly support the presence of circumstellar disks around intermediate mass stars with forbidden line emission. An implication of our findings is that the same outflow model must be applicable to these Herbig Ae/Be stars and the classical T Tauri stars.