Why do I get the following warnings?
WARNING: OSIP file contains invalid data for the region 512<=CHIPX<=768 608<=CHIPY<=640 at 0.1 keV. WARNING: OSIP file contains invalid data for the region 512<=CHIPX<=768 608<=CHIPY<=640 at 0.277 keV.
This warning is innocuous. Events at energies < 0.3 keV are pretty much outside the supported range of wavelength by HETG/ACIS-S (the events would fall off the chips). The gARFs should be fine for use in the analysis.
