IBEX Data Release 4
This fourth data release contains data used in the publication of McComas et al., 2012, "The First Three Years of IBEX Observations and Our Evolving
Heliosphere" . IBEX results, together with in situ observations from
the Voyager-1 and -2 spacecraft currently in the inner heliosheath,
other supporting observations from several spacecraft, and a broad
theory and modeling effort are producing a revolutionary new
understanding of the outer heliosphere and its interactions with the
local interstellar medium. In this release, we provide new ENA
observations from IBEX, covering its first, second and third years of science
operations. For questions about this or any other release, please email email@example.com.
Individual data directories and related skymaps by type may be accessed by selecting the IBEX instrument of interest in the buttons above and then selecting one of the particular type of skymaps in the table (and referred to in the paper). Each page will allow you to explore all the skymap images or subsets by energy type or flux.
To download the data release as a tar file or to go to a table of plots and data selections per instrument, click on one of the links below. To learn more about the structure and content of the files contained in the various released directories, a detailed description follows.
Data Directory Structure and Naming Conventions
Within the data directories there are subdirectories associated with each type of skymap. The following keywords or phrases embedded into the subdirectory names indicate the processing options used to create the skymaps.
- cg - Compton-Getting
- tabular - Survival Probabilities
- noSP - no Survival Probabilities
- ram - Ram direction
- antiram - Antiram direction
- mapx - x identifies a particular set of orbits spanning 6 months.
- yearx - x identifies a particular set of orbits spanning one year.
The 6-months and annual allsky maps are representative of the following IBEX orbits and dates:
||Start-End of Orbits or Arcs
||12/25/2008 – 06/26/2009
|| 06/26/2009 – 12/26/2009
||12/26/2009 – 06/26/2010
|| 06/26/2010 – 12/26/2010
||12/26/2010 – 06/25/2011
|| 06/25/2011 – 12/24/2011
Within each subdirectory there are a number of files associated with each sensor energy range that were used to create the skymap. File names that end with .txt (except -desc.txt) contain ASCII representations of particular data products. The data product with the file name "hv60.hide-trp-flux100-hi-2-ener.txt", for instance, identifies a flux (at 1 AU or at 100 AU if survival probabilities were applied) related file produced from the Hi instrument direct events (hide), triple (trp) coincidence types, energy sensor (2), with a type of 'energy' output data (ener), and that it is ASCII text data (.txt). The skymap plots with the .png suffix, accessible through the links in the "Plots" table below, are based on various calculations using these data products.
The -desc.txt files contain summary descriptions of the types and names of data files used to produce the plot files. Here is a listing of hv60.hide-trp-flux100-hi-2-desc.txt to illustrate:
Flux transported from 1 AU to 1.0 AU
|Samples per Pixel
|Total Counts Data
|Raw Orbit Data
Pixel Size: 6.000 x 6.000 degrees
|Constructed from file(s):
|. . .
With additional parameters:
data spread 6 spin-ward 7 sun-ward degrees
with range 7 spin-ward 7 sun-ward degrees
variance weighting disabled
exposure weighting enabled
nearest neighbor disabled
Normal de-ram corrections
Longitude-aligned orbit frames
Sun-ward range decreases towards NEP
Additional supporting files:
. . .
. . .
. . .
plot_title: 60d: hv60 hide trp
ener_title: ~0.71 keV
NOTE: Intermediate files, such as those listed as 'Constructed from" or "Additional supporting", are not provided as part of the Data Release.
Mono-Energetic Global Flux Maps
Some of the directories also contain a set of variable energy maps interpolated/extrapolated to a fixed energy.
The energy chosen is that of the center of the ESA channel in the s/c frame. These file
names are similar to the variable energy file names. E.g. hv60.hide-trp-mono_80-1.11-flux, is the hv60 cull, the hide data type (direct events from Hi), coincidence type
trp (triples), extrapolated to energy 1.11 keV (ESA channel 3).
There are fewer members to this family of products:
- flux: the flux estimate
- fvar: the variance (sigma squared) of the estimate
- fsnr: the signal-to-noise (flux/sigma) of the estimate
- desc: processing options
- parm-0: which contains the average spectral slope.
Each individual data product file features a header describing the processing options used to create it. Here is the header from one such file. int the data file, the comment header would be followed by an array of numbers formatted per line based on the numbers 30x60 (30 rows by 60 columns) in the first line, or 30 rows of declination by 60 columns of right ascension values. The data value units are provided in either the "desc=" or "title=" entries.
# Sat Sep 1 19:53:41 2012
# -s matrix
# -0 dec (addresses incr. downwards)
# -1 ra (addresses incr. left->right)
# h_min=0.000000 h_max=559.000000 h_title='Total Counts'
# min_0=-90 max_0=90 num_0=30 title_0='Dec (deg)'
# min_1=0 max_1=360 num_1=60 title_1='R.A. (deg)'
# desc="'flux (ENAs / cm^2 s sr keV)'"
# skyframe=ECLIPJ2000 posframe=J2000
# chat=0 smearspread='0/0/0' calc='0/0/0'
# frame_epoch=914629271.873 resp_class=hi_triple zaxis_ra_deg=+274.476346 zaxis_dec_deg=-22.782473
# ram_ra_deg=+187.1048 ram_dec_deg=-3.4879 mtype_list='05,0A,0E' energy_list='12'
# rate_factor='1000' bg_rate=0.05870 bg_rvar=.0000012100 e_nominal='0.71'
# g_factor='0.000406114' inv_method='it3ptfive,20,0.5,f,h,1.5625' meth_opts='20,0.500000,f,h,1.562500'
Spectral figures in the paper were derived from maps at different energies.
Combined maps were calculated as:
(example of combining the first three maps)
;Weights (exposure times)
;Combined fluxes, Variances, signal-to-noise
flux=flux1*wt1 + flux2*wt2 + flux3*wt3
var=var1*(wt1)^2 + var2*(wt2)^2 + var3*(wt3)^2
snr=flux/( sqrt(var) )