2 research outputs found
A Correlation Between Pre-Main Sequence Stellar Rotation Rates and IRAC Excesses in Orion
Early observations of T Tauri stars suggested that stars with evidence of
circumstellar accretion disks rotated slower than stars without such evidence,
but more recent results are not as clear. 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 large samples of PMS stars covering
a broad mass range in nearby star-forming regions. Megeath and collaborators
surveyed the Orion Molecular Clouds (~1 Myr) with the IRAC instrument (3.6,
4.5, 5.8, 8 microns) as part of a joint IRAC and MIPS GTO program. We examine
the relationship between rotation and Spitzer mid-IR fluxes for ~900 stars in
Orion for stars between 3 and 0.1 Msun. We find in these Spitzer data the
clearest indication to date that stars with longer periods are more likely than
those with short periods to have IR excesses suggestive of disks.Comment: 19 pages, 7 figures, accepted by Ap