Monday, September 15, 2008

Flux calibration scales at the VLA?

I've run into what looks like a systematic offset between flux scales of earlier observations and my observations. I'm using the 1999.2 coefficients to set my flux scale and it looks like the earlier observations are using the coefficients from Baars et al. (1977). Any ideas on what the differences are between these two systems? 5%? 10%? 20%? I've tried searching the VLA calibration documentation for the information, but didn't find anything useful (although maybe I missed something).


James said...

The differences are <3%, and are frequency-dependent. Check the bottom of for a table of the exact ratios between Baars et al. and any of the other VLA coefficients.

amanda said...

Good to know! Thanks James.