Katrina Exter, ESAC PACS Instrument and Calibration Scientist
27 Oct 2017, v1
Most PACS spectroscopy SPG products are background subtracted. If one wished to compare the on-source to the off-source data separately, it would be necessary to re-process the data in HIPE. This has been done and the resulting on-source and off-source cubes are provided as this HPDP
For each observation, for each camera and each wavelength slice in the observation, one "equidistant mosaic cube" of the on-source pointing and one (for the unchopped mode) or two (for the chop-nod mode) cubes of the off-source pointings, is provided. For details of how these cubes were created and how they can be used, please read the Release Note.
In addition to the FITS files and the postcards for each observation, the scripts that were used to create these HPDPs are provided here. These can be used to create alternative versions of the HPDP cubes, following the advice in the Release Note and in the related Technical Note which explains what to do if you find "contamination" in your off-source data.
As the entire dataset is very large, the individual files (for each queried obsid) can only be gotten via the HPDP functionality of the HSA.
In the directories, the products are provided as .fits.gz files. We have used the standard naming convention:
where OBSID is the observation identification number, SUFFIX is either [eqir,eqib] for the red and blue “equidistant” interpolated cubes, or [eqpr,eqpb] for the “equidistant” projected cubes. Which you get depends on the pointing mode of the observation. ON and OFF are self-explanatory, while OFFA and OFFB are the two off-source positions of chop-nod observations. ## is the slice number. Note that the slice number is not preceded by an s as it is in an SPG download.
These cubes should load into any cube-viewing software; the spectral and spatial dimensions are fully defined. The FITS file sizes range from a few to about 20 MB.
These data are for inspecting/comparing on-source and off-source data. Please read the Release Note and links therein to learn about how to use (and not use) these HPDP cubes.