Accepted Cycle 9 Observing Proposals

Proposal Number: 09910027

Title: The Great Nebula in Carina: Protoplanetary Disks to Starburst Galaxies (GTO component)

PI Name: Gordon Garmire

The Great Nebula in Carina is a remarkable and ideal site to study the violent high-mass star formation and feedback that typifies starburst galaxies. We propose to map the Carina star-forming complex with a mosaic of 60-ks ACIS-I pointings as a testbed for understanding recent and ongoing star formation and to probe regions of bright diffuse X-ray emission seen throughout the complex by ROSAT.

Proposal Number: 09910161

Title: The Great Nebula in Carina: Protoplanetary Disks to Starburst Galaxies

PI Name: Leisa Townsley

The Great Nebula in Carina is a superb site to study the violent massive star formation and feedback that typifies giant HII regions and starburst galaxies. We propose to map the Carina star-forming complex with a mosaic of 20 new 60-ks ACIS-I pointings as a testbed for understanding recent and ongoing star formation and to probe its regions of bright diffuse X-ray emission. We will provide a catalog of multiwavelength properties of ~12,000 X-ray-selected stars. We will explore superbubble confinement, shocks, cloud evaporation, mass-loading of winds, ISM enrichment, and HII region energetics. We will also examine Carina as a surrogate environment for our Solar System's formation, where protoplanetary disks are bathed in harsh winds and radiation from nearby massive stars.

Proposal Number: 09910246

Title: THE ORIGIN OF THE GALACTIC RIDGE X-RAY EMISSION

PI Name: Mikhail Revnivtsev

We propose a very deep (900 ksec) observation of a carefully selected patch of the Galaxy. This observation will provide the most direct and unambiguous answer to the 30-year-old puzzle of the nature of the Galactic "diffuse" X-ray emission. Recent studies comparing the luminosity function of X-ray sources in the Solar neighborhood with the number-flux distributions toward the Galactic Center and plane strongly suggest that the GRXE can be explained by the integrated emission of millions of faint stellar sources - CVs and coronally active stars. The surface density of them is expected to exceed 1 per 60sq.sec in the proposed observation, in sharp contrast to the expectation in the diffuse model. Clearly, Chandra is the only mission in the foreseeable future which can solve this problem.

Proposal Number: 09910432

Title: Intermediate-Age Elliptical Galaxies

PI Name: Dong-Woo Kim

We propose to observe intermediate-age elliptical galaxies, with Chandra for a total exposure of 280ks. Existing Chandra observations of a small number of similar galaxies suggest very intriguing age-related effects when compared with those of typical old ellipticals: (1) a flatter luminosity function of LMXBs with a larger number of luminous X-ray sources and (2) an asymmetric spatial distribution of LMXBs. We will confirm these signatures of star formation episodes to provide the first X-ray age-estimator applied to elliptical galaxies and to set strong constraints on theoretical models of X-ray binary formation.