The targets, identified by a unique HOPS number, were observed
in various groups using the PACS instrument on Herschel in scan
mode; each group's observations is specified in two AORs, one
for the scan and one for the cross-scan. Each group was observed
using the 70 and 160 micron filter on PACS. Some groups contain
a large number of HOPS targets, while other encompass very few.

Delivered maps for each group were reduced with two different mappers:
(1) high-pass filter with photProject and (2) scanamorphos. These
are the files ending in "HPF_PACS70.fits", "HPF_PACS160.fits",
"scanamorphos_PACS70.fits", and "scanamorphos_PACS160.fits".
We also deliver the source masks used for the high-pass filter;
these are the files ending in "PACS70_mask.fits" and
"PACS160_mask.fits". Thus, each group has 6 files associated
with it (but note that some groups do not have mask files).

Each fits file that contains either "HPF" or "scanamorphos"
in its file name has three extensions: the first one is the
signal map (in Jy/pixel), the second is the error map (in
Jy/pixel), and the third one is the coverage map. The main
header of each fits file contains information on the telescope,
instrument, target, pointing, observing times, data products,
and the OTKP proposal.

Recommended usage: the HPF products for aperture photometry, 
the scanamorphos products for PSF photometry. HPF filters out 
low-frequency signals in a way that preserves point sources, 
but might introduce artifacts in the extended emission. 
To analyze extended emission in the PACS maps, it is best to use 
the scanamorphos products. 

If you use HOPS data, please cite Furlan et al. (2016).