Talk abstract details
SOFIA Observations of the Planetary Nebula NGC 7009
Abstract
We report spectrophotometric observations
made with SOFIA/FORCAST currently
scheduled for 1 June 2011. Optical
measurements have shown that the abundance
discrepancy factor (adf) varies with
position in several high-adf PNe and is
highest close to the central star. The
very low electron temperature inclusions,
postulated to explain the abundance
discrepancy, must be cooled predominantly
by fine structure IR lines. These SOFIA data
will map mid-IR FS lines (and our related
Herschel program will add several far-IR FS
lines) in the bright, well-characterized,
high-adf PN NGC 7009. We will compare
these IR results with FS optical line
measurements in order to correlate ratios
of IR to optical fluxes with position, and
thus correlate with where the the adf peaks.
made with SOFIA/FORCAST currently
scheduled for 1 June 2011. Optical
measurements have shown that the abundance
discrepancy factor (adf) varies with
position in several high-adf PNe and is
highest close to the central star. The
very low electron temperature inclusions,
postulated to explain the abundance
discrepancy, must be cooled predominantly
by fine structure IR lines. These SOFIA data
will map mid-IR FS lines (and our related
Herschel program will add several far-IR FS
lines) in the bright, well-characterized,
high-adf PN NGC 7009. We will compare
these IR results with FS optical line
measurements in order to correlate ratios
of IR to optical fluxes with position, and
thus correlate with where the the adf peaks.