Normalized spectra (arbitrarily shifted for clarity) of detected early-type stars. The positions of lines from H i, He i, and He ii are marked and labeled at the top, along with those of other detected lines from Si iv, N iii, and C iv. The spectra were multiplied by the black body of the standard star. Dotted lines show black bodies with the temperatures inferred from the observed stellar spectral types; these black bodies were reddened with individual A_Ks values (for details see Sect. 3.2).