Rotation/saturation/dynamos -- Oral Presentation

Rotation and Spitzer/IRAC fluxes in Orion

Luisa Rebull, Spitzer Science Center

J.R. Stauffer, T. Megeath, J. Hora, L. Hartmann

Much effort has been expended in recent years in an effort to decipher the influence of circumstellar disks on rotation in pre-main-sequence stars. Early observations of TTauri stars suggested that stars with evidence of circumstellar accretion disks rotated slower than stars without such evidence. More recent observations have muddied the waters. Complicating this discussion, near-IR circumstellar disk indicators, though the most widely available, are subject to uncertainties that can result from inner disk holes and/or the system inclination. Mid-infrared observations are less sensitive to such effects, but until now, these observations have been difficult to obtain. The Spitzer Space Telescope now easily enables mid-infrared measurements of many stars at once down to substellar masses. In this contribution, we will examine the relationship between rotation and Spitzer mid-IR fluxes for $\sim900$ stars in Orion ($\sim5$ Myr) for stars between 3 and 0.1 M$_{sun}$. These data were obtained as part of a Spitzer IRAC and MIPS joint GTO program (Megeath et al. 2005, in prep).