Discovery of the high--ionization emission line [Ne V] 3426 in the blue compact dwarf galaxy Tol 1214-277

The discovery of the high-ionization [Ne V] 3426A emission line in the spectrum of the blue compact dwarf (BCD) galaxy Tol 1214-277 is reported. The detection of this line implies the presence of intense ionizing X-ray emission with a luminosity in the range 10^39-10^40 erg/s. Such a high X-ray luminosity cannot be reproduced by models of massive stellar populations. Other mechanisms, such as fast shocks or accretion of gas in high-mass X-ray binaries need to be invoked to account for the high intensity of the [Ne V] 3426A emission line.