Specific Star Forming Regions -- Oral Presentation

COUP: The Chandra Orion Ultradeep Project

Eric Feigelson, Penn State University

In January 2003, the Chandra X-ray Observatory pointed at the Orion Nebula region nearly continuously for 2 weeks. A wide range of studies by an international collaboration of scientists is emerging from this observation of unprecedented duration and sensitivity. We start with an overview of the X-ray luminosity function of the Orion Nebula Cluster population with insights into the dependencies of magnetic activity on stellar mass, age, accretion and rotation. Hundreds of powerful magnetic reconnection flares are seen at levels orders of magnitude above that seen in main sequence stars. The relationship between X-ray, optical and infrared surveys are then discussed. COUP confirms the cluster membership of 1315 stars, discovers several dozen new members, and places interesting limits on the low-mass population of the embedded cluster around the Orion Hot Core. COUP detects stars with obscuration as high as 500 visual magnitudes. We end with a brief discussion of the potential astrophysical effects of X-rays on star and planet formation. COUP provides new evidence that X-rays can efficiently irradiate protoplanetary disks and, if an embedded cluster is present, will produce X-ray Dissociation Regions over significant fractions of molecular cloud cores.