X-ray emission from A0-F6 spectral type stars

We use the ROSAT public data archive to study the X-ray emission of a sampl e of supposedly single A0-F6 spectral type stars from the Bright Star Catal ogue. We detected X-ray emission from 19 A- and 33 F-type stars. However, o ur results are not sufficient to associate with certainty the X-ray emissio n to the A-type stars themselves, since the usual argument that it may orig inate from a binary companion cannot be excluded. A spectral analysis was c onducted for 14 sources (3 A and 11 F), finding that for 12 of them a two t emperature thermal plasma model is needed to reproduce the observed spectra . The two temperatures are centered at 0.13 and 0.54 keV, respectively. The values found for the higher temperature are lower than that ones of X-ray selected single late-type stars. The X-ray luminosities are in the range L- X similar to 10(28)-10(30) erg s(-1), with a distribution similar to that o f active late-type stars. No correlation is found between L-X and B-V color , V sin i and L-bol, while a positive correlation is found between the X-ra y luminosity and the hardness ratio.