A Deep Chandra Observation of the Giant HII Region N11 I. X-ray Sources
  in the Field
  A very sensitive X-ray investigation of the giant HII region N11 in the LMC
was performed using the Chandra X-ray Observatory. The 300ks observation
reveals X-ray sources with luminosities down to 10^32 erg/s, increasing by more
than a factor of 5 the number of known point sources in the field. Amongst
these detections are 13 massive stars (3 compact groups of massive stars, 9
O-stars and one early B-star) with log(Lx/Lbol)~-6.5 to -7, which may suggest
that they are highly magnetic or colliding wind systems. On the other hand, the
stacked signal for regions corresponding to undetected O-stars yields
log(Lx/Lbol)~-7.3, i.e., an emission level comparable to similar Galactic stars
despite the lower metallicity. Other point sources coincide with 11 foreground
stars, 6 late-B/A stars in N11, and many background objects. This observation
also uncovers the extent and detailed spatial properties of the soft, diffuse
emission regions but the presence of some hotter plasma in their spectra
suggests contamination by the unresolved stellar population.
