The ASCA calibration has evolved considerably since launch and indeed, is
still evolving. There have been concerns in the literature that changes in the
ASCA calibration have resulted in the Fe-Kalpha lines in active galaxies (AGN)
now being systematically narrower than was originally thought. If this were
true, a large body of ASCA results would be impacted. In particular, it has
been claimed that the broad red wing (when present) of the Fe-Kalpha line has
been considerably weakened by changes in the ASCA calibration. We demonstrate
explicitly that changes in the ASCA calibration over a period of about eight
years have a negligible effect on the width, strength, or shape of the
Fe-Kalpha lines. The reduction in both width and equivalent width is only ~8%
or less. We confirm this with simulations and individual sources, as well as
sample average profiles. The average profile for type 1 AGN is still very
broad, with the red wing extending down to ~4 keV. The reason for the claimed,
apparently large, discrepancies is that in some sources the \fekalfa line is
complex, and a single-Gaussian model, being an inadequate description of the
line profile, picks up different portions of the profile with different
calibration. Single-Gaussian fits do not therefore model all of the line
emission in some sources, in which case they do not compare old and current
calibration since the models do not then describe the data.Comment: Accepted for publication in the Astrophysical Journal, Vol. 569, 10
April, 2002. 22 pages, 4 figure