We present the first high-spatial-resolution X-ray images of two high-mass star forming regions , the Omega Nebula ( M 17 ) and the Rosette Nebula ( NGC 2237–2246 ) , obtained with the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer ( ACIS ) instrument .
The massive clusters powering these H II regions are resolved at the arcsecond level into > 900 ( M 17 ) and > 300 ( Rosette ) stellar sources similar to those seen in closer young stellar clusters .
However , we also detect soft diffuse X-ray emission on parsec scales that is spatially and spectrally distinct from the point source population .
The diffuse emission has luminosity L _ { x } \simeq 3.4 \times 10 ^ { 33 } ergs s ^ { -1 } in M 17 with plasma energy components at kT \simeq 0.13 and \simeq 0.6 keV ( 1.5 and 7 MK ) , while in Rosette it has L _ { x } \simeq 6 \times 10 ^ { 32 } ergs s ^ { -1 } with plasma energy components at kT \simeq 0.06 and \simeq 0.8 keV ( 0.7 and 9 MK ) .
This extended emission most likely arises from the fast O-star winds thermalized either by wind-wind collisions or by a termination shock against the surrounding media .
We establish that only a small portion of the wind energy and mass appears in the observed diffuse X-ray plasma ; in these blister H II regions , we suspect that most of it flows without cooling into the low-density interstellar medium .
These data provide compelling observational evidence that strong wind shocks are present in H II regions .