We analyzed archival Chandra X-ray observations of the central portion of the
30 Doradus region in the Large Magellanic Cloud. The image contains 20 X-ray
point sources with luminosities between 5×1032 and 2×1035 erg s−1 (0.2 -- 3.5 keV). A dozen sources have bright WN
Wolf-Rayet or spectral type O stars as optical counterparts. Nine of these are
within ∼3.4pc of R136, the central star cluster of NGC2070. We derive an
empirical relation between the X-ray luminosity and the parameters for the
stellar wind of the optical counterpart. The relation gives good agreement for
known colliding wind binaries in the Milky Way Galaxy and for the identified
X-ray sources in NGC2070. We conclude that probably all identified X-ray
sources in NGC2070 are colliding wind binaries and that they are not associated
with compact objects. This conclusion contradicts Wang (1995) who argued, using
ROSAT data, that two earlier discovered X-ray sources are accreting black-hole
binaries. Five of the eighteen brightest stars in R136 are not visible in our
X-ray observations. These stars are either single, have low mass companions or
very wide orbits. The resulting binary fraction among early type stars is then
unusually high (at least 70%).Comment: 23 pages, To appear in August in Ap