Based on the Chandra Orion Ultradeep Project ( COUP ) observation , we establish the global X-ray properties of the stellar population associated with the Orion Nebula .
Three components contribute roughly equally to the integrated COUP luminosity in the hard ( 2 - 8 keV ) X-ray band : several OB stars , 822 lightly obscured cool stars in the Orion Nebula Cluster ( ONC ) , and 559 heavily obscured stars .
ONC stars 0.5 - 2 pc from the center show a spatial asymmetry consistent with violent relaxation in the stellar dynamics .
The obscured COUP sources concentrate around both OMC-1 molecular cores ; these small-scale structures indicate ages t \lesssim 0.1 Myr .
The X-ray luminosity function ( XLF ) of the lightly obscured sample is roughly lognormal in shape .
The obscured population is deficient in lower-luminosity stars , perhaps due to localized circumstellar material .
Mass-stratified XLFs show that one-third of the Orion Nebula region hard-band emission is produced by the bright O6 star \theta ^ { 1 } Ori C and half is produced by lower mass pre-main sequence stars with masses 0.3 < M < 3 M _ { \odot } .
Very low mass stars contribute little to the cluster X-ray emission .

Using the hard band emission , we show that young stellar clusters like the ONC can be readily detected and resolved with Chandra across the Galactic disk , even in the presence of heavy obscuration .
The Orion Nebula sample is a valuable template for studies of distant clusters .
For example , the peak of the XLF shape can serve as a standard candle for a new distance measure to distant young stellar clusters , and the presence of a neon emission line complex around 1 keV can serve as a diagnostic for young stars .