iraf.net

I am extracting a spectrum of a star by iraf. During the several steps near the end , I meet a flux calibration problem .

Anybody knows why?



calibrate input=@imagelist3//btfc_tran.0001 output=@imagelist3//flux extinct+ flux+ \
extinction="./extinct.dat" observa="ctio" sensiti="sens" fnu-


Before the step "calibrate"



After "calibrate" ,I get the spectrum like this:



the sensitivity function:

I put the three figures here.

http://blog.sina.com.cn/s/blog_e7b4fe4b0101g9jy.html

Could anybody give some advice?