No X-Ray--luminous Starbursts in the Einstein Medium Sensitivity Survey, Either

We continue to investigate recurrent claims that a substantial number of "normal" star-forming galaxies may have X-ray luminosities in the range 10^42-44 ergs s^-1. In this installment, we present new spectra of four such emission-line galaxies that were ambiguously classified in the Einstein Extended Medium Sensitivity Survey (EM SS), and find that they all have intermediate-type Seyfert nuclei as evidenced by broad components of their Hα lines. We argue that any of the remaining emission-line galaxies in the EMSS with 10⁴² < L_χ < 10⁴⁴ ergs s^-1 that were flagged as needing further spectroscopic work are almost certain to have active nuclei as well. We conclude that in these as well as other samples of X-ray-selected emission-line galaxies, X-ray luminosities in excess of 1042 ergs s 1 can and should be attributed to an active nucleus, even in the case that most of the infrared continuum or optical emission-line luminosity is caused by star formation. There is as yet no good evidence for X-ray-luminous starbursts.