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IRS *_tune.tbl
The following table approximate what the 1-D post-BCD spectral extraction
pipeline at the SSC will produce. Separate tables will be produced for
each BCD (thus, commanded slit position) within an AOR. For example,
separate extracted spectra would be produced for Short-Low 1st Order and for
Short-Low 2nd Order observations. Short-Low 2nd Order observations also
include the "Bonus" order (labeled order "3" in those tables) that overlap
some Short-Low 1st Order wavelengths. In the future, coadded 1-D spectra
will be produced for specta within and AOR obtained at the same slit
position. For scan maps where "both" orders were selected in Spot for a
Short-Low or Long-Low observation, the table will contain the 1st, 2nd, and
bonus orders for each commanded position in the scan map.
Each table contains a subset of FITS header keyword information and some
history of the processing done by the SSC pipeline. The tables contain
five formatted columns in IPAC ASCII table format
(column widths defined by the | | in the table headers):
order - The order corresponding to the extracted data.
wavelength - The wavelength (in microns) of the extracted data.
flux_density - Extracted flux density in Janskys.
uncertainty - The error associated with the extracted data.
bit-flag - A number calculated from the addition of all pipeline-set bits
in a 16-bit signed number with each bit corresponding to a
unique pixel mask condition. For example, the following bits
correspond to the following conditions:
Bit # Condition
----------
2 Digital saturation detected in sample(s) along ramp
3 Radhit detection along ramp in sample(s) along ramp
4 Non-linearity correction could not be computed in sample(s) along ramp
.
.
.
Therefore, in the example files provided, two numbers are
present in the bit-flag column, 8 and 28. These correspond
to the following:
8 = 2^3 -> Bit 3 is set -> Radhit detection along ramp
28 = 2^4 + 2^3 + 2^2 -> Bits 2,3,4 are all set which signifies
digital saturation detected along a
ramp, radhit detection along a ramp,
and the non-linearity correction could
not be computed for a sample along ramp.
These bit flag numbers will be described further in a future
Data Products Document.
Example
An example is shown here.
These data simulate an IRS Short-Low 2nd Order observation at an
approximate IRS resolution (R) of 100. The spectrum is has been generated
at the IRS sampling wavelengths.
Go back to IRS Data Products Example page
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