Hot Subdwarf Stars Observed in LAMOST DR1 - Atmospheric parameters from single-lined spectra

摘要: We present a catalog of 166 spectroscopically identified hot subdwarf stars from LAMOST DR1, 44 which show the characteristics cool companions in their optical spectra. Atmospheric parameters 122 non-composite spectra were measured by fitting profiles hydrogen (H) and helium (He) lines with synthetic non-LTE model atmospheres. Most sdB scatter near Extreme Horizontal Branch $T_{\rm eff}-\log{g}$ diagram two well defined groups can be outlined. A clustering He-enriched sdO appears eff}=45\,000$ K $\log(g) = 5.8$. The population separates into several nearly parallel sequences eff}-{\rm He}$ abundance clumps corresponding to those diagram. Over $38\,000$ (sdO) extremes, they are either He-rich or He-deficient we observe only few $ -1 < \log(y) 0$ range. With increasing temperature these extremes become less prominent He approaches $\log(y)\sim-0.5$. unique property our sample is that it covers large range apparent magnitudes galactic latitudes, therefore contains mix different populations environments. Our results consistent findings Hirsch (2009) conclude ($\log(y) 1$) probably origin populations. also find most lie narrow strip luminosity plane, suggests atmospheric correlated.