The Spitzer GTO Survey of Circumstellar Disks in Young Stellar Clusters
Abstract
We present results from the first year of a survey of young stellar clusters mapped with the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS). The sample spans an age range of 1-100 Myr and a wide variety of stellar densities and radiation environments, with the ultimate goal of constraining circumstellar disk properties and lifetimes as a function of mass and environment. We have selected likely disk-bearing sources based on mid-infrared excesses as inferred from their IRAC and MIPS colors. Combining observations with ground-based near-infrared photometry, we have compiled spectral energy distributions from 1-24 microns with which we can broadly characterize circumstellar disk properties. We find significant evidence of evolution in both the primordial and debris disk phases. In particular, we have discovered a population of objects as young as 1 Myr showing possible inner disk clearing within 1 AU, perhaps primordial disks caught in the act of dissipating. Amongst the older 20-100 Myr clusters, we have found a large dispersion in the level and frequency of excess emission, including a small number of surprisingly strong 24-micron excess sources around solar-type stars, indicating a wide variation in planetary debris disk properties at any given stellar mass and age.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AAS...205.1701M