Hot stars from LAMOST DR6

We implement the simultaneous fitting of these 11 stellar labels to LAMOST hot-star spectra using the PAYNE approach, drawing on Kurucz's ATLAS12/SYNTHE LTE spectra as the underlying models. We then obtain stellar parameter estimates for a sample of about 330000 hot stars with LAMOST spectra, an increase by about two orders of magnitude in sample size. Among them, about 260000 have S/N>5 Gaia parallaxes, and their luminosities imply that >~95% among them are luminous star, mostly on the main sequence; the rest reflects lower luminosity evolved stars, such as hot subdwarfs and white dwarfs.

We show that the fidelity of the results, particularly for the abundance estimates, is limited by the systematics of the underlying models, as they do not account for NLTE effects. Finally, we show the detailed distribution of v sin i of stars with 8000-15000K, illustrating that it extends to a sharp cut-off at the critical rotation velocity, vcrit, across a wide range of temperatures.