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Challenges in Analyzing Data from the GLAST Large Area Telescope
J. Chiang (GLAST Science Support Center, UMBC/GSFC)

The Large Area Telescope (LAT) aboard GLAST promises greater than an
order of magnitude better sensitivity, a much larger field-of-view,
significantly better angular resolution, and broader energy coverage
than its predecessor in the gamma-ray band, EGRET. Nevertheless, LAT
data will still present many statistical challenges that are
encountered usually only to a much lesser degree in analyses of other
astronomical data. Because of the LAT's relatively broad point spread
function, source confusion will be a significant concern, especially
at lower energies; and the strong energy dependence of the psf makes
decoupling the spectral analysis of a source from the spatial part
problematic. Furthermore, the LAT PSF, effective area, and energy
dispersion depend strongly on the direction with respect to the
instrument axes. This, coupled with the LAT's large field-of-view
($\sim 2$ sr) and scanning mode of operation, means that the
instrument response to any point on the sky can change significantly
on time scales comparable to those expected for the intrinsic
variability of many sources. Despite these difficulties, the analysis
goals for the LAT are much the same as for other missions: source
detection, identification, and characterization in the time, energy,
and spatial domains. I will discuss some of the efforts being made to
attain these goals, including maximum likelihood analysis, and
somewhat less conventional methods such as Bayesian Blocks as well as
wavelet analyses and other multi-scale techniques.