  The X-ray light curves of pre-main sequence stars can show variability in the
form of flares altering a baseline characteristic activity level; the largest
X-ray flares are characterized by a rapid rise to more than 10 times the
characteristic count rate, followed by a slower quasi-exponential decay.
Analysis of these high-contrast X-ray flares enables the study of the innermost
magnetic fields of pre-main sequence stars. We have scanned the ANCHORS
database of Chandra observations of star-forming regions to extend the study of
flare events on pre-main sequence stars both in sky coverage and in volume. We
developed a sample of 30 high-contrast flares out of the 14,000 stars of
various ages and masses available in ANCHORS at the start of our study.
Applying methods of time-resolved spectral analysis, we obtain the
temperatures, confining magnetic field strengths, and loop lengths of these
bright, energetic flares. The results of the flare analysis are compared to the
2MASS and Spitzer data available for the stars in our sample. We find that the
longest flare loop lengths (of order several stellar radii) are only seen on
stars whose IR data indicates the presence of disks. This suggests that the
longest flares may stretch all the way to the disk. Such long flares tend to be
more tenuous than the other large flares studied. A wide range of loop lengths
are observed, indicating that different types of flares may occur on disked
young stellar objects.
