https://spdf.gsfc.nasa.gov/pub/data/ibex/hi/time_series/histograms/aareadme.txt

This directory provides six energy band-specific subdirectories containing 8-day (full IBEX orbit) histogram files produced by the IBEX-Hi instrument.   

Each record of a histogram captures the number of arriving ENA's of a specific energy band, coincidence type, and spin phase.  Data for each full ~15s spacecraft spin are given at each of 60 spin phases in sequential records, with the J2000 right ascension and declination for look directions corresponding to each spin phase being given in the corresponding record.  Also included in each record are a time tag (seconds since 00:00 UT of January 6, 1980), the IBEX location, ENA energy band and coincidence type.  Positive species identifications are not made, but most arriving ENA's are hydrogen atoms.  Data files are given for each 8-day orbit and for each of the 6 IBEX-Hi energy bands.

Each data file has header material describing the words in the data records.  The TS_description.txt file in the parent directory should be studied to more fully understand these low level data.  File naming is addressed in the readme two directory levels up.