Previous | Session 17 | Next
J. Muzerolle, N. Gorlova, G. H. Rieke, N. Siegler, E. T. Young (Steward Observatory), S. T. Megeath, L. E. Allen, G. G. Fazio, L. Hartmann, C. J. Lada, K. L. Luhman, P. C. Myers, A. Porras, A. Sicilia-Aguilar (Harvard-Smithsonian Center for Astrophysics), K. Flaherty, R. Gutermuth (University of Rochester), J. R. Stauffer (SSC, Caltech), MIPS Team, IRAC Team
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.
Previous | Session 17 | Next
Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.