A sample of X-ray emitting normal galaxies from the BMW -- HRI Catalogue

We have obtained a sample of 143 normal galaxies with X-ray luminosity in the range ${10}^{38}-{10}^{43}$ erg s${}^{-1}$ from the cross-correlation of the ROSAT HRI Brera Multi-scale Wavelet (BMW – HRI) Catalogue with the Lyon-Meudon Extragalactic Database (LEDA). We find that the average X-ray properties of this sample are in good agreement with those of other samples of galaxies in the literature. We have selected a complete flux limited serendipitous sample of 32 galaxies from which we have derived the logN-logS distribution of normal galaxies in the flux range $1.1-110\times {10}^{-14}$ erg cm${}^{-2}$ s${}^{-1}$. The resulting distribution is consistent with the euclidean -1.5 slope. Comparisons with other samples, such as the Extended Medium Sensitivity Survey, the ROSAT All Sky Survey, the XMM - Newton/2dF survey and the Chandra Deep Field Survey indicate that the logN-logS distribution of normal galaxies is consistent with an euclidean slope over a flux range of about 6 decades.