Identification and Spectroscopic Characterization of 128 New Herbig Stars

We present optical spectroscopy observations of 145 high-mass pre-main-sequence candidates from the catalog of Vioque et al. 2020 From these, we provide evidence for the Herbig nature of 128 sources. This increases the number of known objects of the class by similar to 50%. We determine the stellar parameters of these sources using the spectra and Gala EDR3 data. The new sources are well distributed in mass and age, with 23 sources between 4 and 8 M-circle dot and 32 sources above 8 M-circle dot. Accretion rates are inferred from H alpha and H beta luminosities for 104 of the new Herbigs. These accretion rates, combined with previous similar estimates, allow us to analyze the accretion properties of Herbig stars using the largest sample ever considered. We provide further support to the existence of a break in accretion properties at similar to 3-4 M-circle dot, which was already reported for the previously known Herbig stars. We re-estimate the potential break in accretion properties to be at 3.87(-0.96)(+0.38)M(circle dot). As observed for the previously known Herbig stars, the sample of new Herbig stars independently suggests intense inner-disk photoevaporation for sources with masses above similar to 7 M-circle dot. These observations provide robust observational support to the accuracy of the Vioque et al. 2020 catalog of Herbig candidates.