2MASS: Is There A Difference
Between North And South?

Sergei Nikolaev
Department of Physics and Astronomy
University of Massachusetts, Amherst, MA 01003-4535
nikolaev@redtail.phast.umass.edu

Abstract:

To test for the systematic differences between North and South 2MASS data, I analyze 10 calibration fields observed from both North and South. The global calibration analysis (in K-band) is performed on the data taken during the period from 05.01.97 to 08.18.98. The analysis shows the presence of systematic error in the Southern data due to non-optimal PSF photometry. Elminating this, the North-South differences are consistent with zero with a 3% root variance. The tests for systematic difference between North and South due to source colors do not show any significant color dependence.