Seven Years of Imaging the Global Heliosphere with IBEX

IBEX Data Release 10

Dave McComas (Princeton University)

The Interstellar Boundary Explorer (IBEX) has now operated in space for seven years and returned nearly continuous observations that have led to scientific discoveries and reshaped our entire understanding of the outer heliosphere and its interaction with the local interstellar medium. This data release extends prior work by adding the 2014-2015 data for the first time and improving prior correction methods. The data, maps, and documentation provided here represent the tenth major release of IBEX data, providing a complete seven year set of Energetic Neutral Atom (ENA) observations from ~0.1 to 6 keV.

To download the entire data release as a zip file or to go to a table of plot directories and data selections for either IBEX-Lo or IBEX-Hi, click on one of the links below. To learn more about the structure and content of the files contained within the release, a detailed description follows. For questions about this or any other release, please email ibex_datareleases@lists.sr.unh.edu.

A detailed description and initial analysis of these maps is presented in McComas et al. 2017 (ApJS, In Press).

Data Directory Structure and Naming Conventions

The data in this release are separated into six-month and one-year segments, which represent the following IBEX orbits and dates:

The 6-month and annual allsky maps are representative of the following IBEX orbits and dates:

Year Skymap # Start-End of Orbits or Arcs Dates
1 Map1 11-34 12/25/2008 – 06/25/2009
1 Map2 35-58 06/25/2009 – 12/25/2009
2 Map3 59-82 12/25/2009 – 06/26/2010
2 Map4 83-106 06/26/2010 – 12/26/2010
3 Map5 107-130a 12/26/2010 – 06/25/2011
3 Map6 130b-150a 06/25/2011 – 12/24/2011
4 Map7 150b-170a 12/24/2011 – 06/22/2012
4 Map8 170b-190b 06/22/2012 – 12/26/2012
5 Map9 191a-210b 12/26/2012 – 06/26/2013
5 Map10 211a-230b 06/26/2013 – 12/26/2013
6 Map11 231a-250b 12/26/2013 – 06/26/2014
6 Map12 251a-270b 06/26/2014 – 12/24/2014
7 Map13 271a-290b 12/24/2014 – 06/24/2015
7 Map14 291a-310b 06/24/2015 – 12/23/2015

Along with each set of individual maps, we provide the 7-year combined map for that category, as well as a combined set of ENA maps in equatorial and galactic coordinate systems for the broader astrophysical community.

Map directories are named using keywords that indicate the type of data they contain:

  • cg - Compton-Getting corrections have been applied to the data to account for the speed of the spacecraft relative to the direction of arrival of the ENAs.
  • tabular - survival probability corrections have been applied to the data to account for the loss of ENAs due to radiation pressure, photoionization and ionization via charge exchange with solar wind protons as they stream through the heliosphere. This correction scales the data out from IBEX at 1 AU to ~100 AU.
  • noSP - no survival probability corrections have been applied to the data.
  • ram - data was collected when the spacecraft was ramming into the incoming ENAs.
  • antiram - data was collected when the spacecraft was moving away from the incoming ENAs.
  • mapx - x identifies a particular set of orbits spanning 6 months.
  • yearx - x identifies a particular set of orbits spanning one year.
  • single - data was collected over the course of the entire seven-year span.

Filename Description

Data and map files are named using additional keywords that indicate the type of data they contain:

  • hide - IBEX-Hi direct events
  • lode - IBEX-Lo direct events
  • hi-n - data from the nth energy bin of IBEX-Hi
  • lo-n - data from the nth energy bin of IBEX-Lo
  • trp - triple coincidence
  • mono - Compton-Getting corrected data
  • flux - flux data
  • fsnr - signal/noise data
  • ener - energies data
  • numb - samples per pixel
  • fexp - total time exposure data
  • cnts - total counts data
  • fraw- raw orbit data
  • fvar- flux variances

File Headers

The first number in the first line of each data file gives the number of lines taken up by the header followed by the number of rows times the number of columns in the data (i.e. 30X60 indicates 30 rows of declination by 60 columns of right ascension values). The keyword “h_title” gives the description of the data and the units used.

IBEX Hi Observing Energetic Neutral Atoms In a Higher Range of Energies

Plots and Data Directories

6-month Compton-Getting Corrected Maps

Compton-Getting maps adjust values after correcting for the speed of the spacecraft in relation to the direction of arrival of the ENAs.

The data directories:

hvset_cg_single

hvset_cg_map1

hvset_cg_map2

hvset_cg_map3

hvset_cg_map4

hvset_cg_map5

hvset_cg_map6

hvset_cg_map7

hvset_cg_map8

hvset_cg_map9

hvset_cg_map10

hvset_cg_map11

hvset_cg_map12

hvset_cg_map13

hvset_cg_map14

6-month Maps

These maps represent the data before any corrections are made for speed of spacecraft or survival probability.

The data directories:

hvset_single

hvset_map1

hvset_map2

hvset_map3

hvset_map4

hvset_map5

hvset_map6

hvset_map7

hvset_map8

hvset_map9

hvset_map10

hvset_map11

hvset_map12

hvset_map13

hvset_map14

Yearly Maps, Ram Direction

These maps include data recorded from times when the aperture was pointed towards the hemisphere of the spacecraft’s motion. The maps do not include survival probability corrections.

The data directories:

Without Compton-Getting

hvset_noSP_ram_single

hvset_noSP_ram_year1

hvset_noSP_ram_year2

hvset_noSP_ram_year3

hvset_noSP_ram_year4

hvset_noSP_ram_year5

hvset_noSP_ram_year6

hvset_noSP_ram_year7

With Compton-Getting

hvset_noSP_ram_cg_single

hvset_noSP_ram_cg_year1

hvset_noSP_ram_cg_year2

hvset_noSP_ram_cg_year3

hvset_noSP_ram_cg_year4

hvset_noSP_ram_cg_year5

hvset_noSP_ram_cg_year6

hvset_noSP_ram_cg_year7

Yearly Maps, AntiRam
Direction

These maps include data recorded at times when the aperture was pointed away from the hemisphere of the spacecraft’s motion. The maps do not include survival probability corrections.

The data directories:

Without Compton-Getting

hvset_noSP_antiram_single

hvset_noSP_antiram_year1

hvset_noSP_antiram_year1

hvset_noSP_antiram_year2

hvset_noSP_antiram_year3

hvset_noSP_antiram_year4

hvset_noSP_antiram_year5

hvset_noSP_antiram_year6

hvset_noSP_antiram_year7

With Compton-Getting

hvset_noSP_antiram_cg_single

hvset_noSP_antiram_cg_year1

hvset_noSP_antiram_cg_year2

hvset_noSP_antiram_cg_year3

hvset_noSP_antiram_cg_year4

hvset_noSP_antiram_cg_year5

hvset_noSP_antiram_cg_year6

hvset_noSP_antiram_cg_year7

6-months, Compton-Getting and
Survival Probability Corrected Maps

Compton-Getting Tabular Maps adjust values after correcting for the speed of the spacecraft in relation to the direction of arrival of the ENAs and include adjustments taking into account ENA survival probability as they move from the outer heliosphere to 1 AU (location of IBEX).

The data directories:

hvset_cg_tabular_single

hvset_cg_tabular_map1

hvset_cg_tabular_map2

hvset_cg_tabular_map3

hvset_cg_tabular_map4

hvset_cg_tabular_map5

hvset_cg_tabular_map6

hvset_cg_tabular_map7

hvset_cg_tabular_map8

hvset_cg_tabular_map9

hvset_cg_tabular_map10

hvset_cg_tabular_map11

hvset_cg_tabular_map12

hvset_cg_tabular_map13

hvset_cg_tabular_map14

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

Survival Probability Lookup Maps

Survival Probability Maps account for the loss (extinction) of ENAs due to radiation pressure, photoionization and ionization via charge exchange with solar wind protons.

The data directories:

hvset_tabular_single

hvset_tabular_map1

hvset_tabular_map2

hvset_tabular_map3

hvset_tabular_map4

hvset_tabular_map5

hvset_tabular_map6

hvset_tabular_map7

hvset_tabular_map8

hvset_tabular_map9

hvset_tabular_map10

hvset_tabular_map11

hvset_tabular_map12

hvset_tabular_map13

hvset_tabular_map14

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

Yearly Maps, Survival Probability Corrected, Ram Direction

These maps include survival probability corrected data recorded from times when the aperture was pointed towards the hemisphere of the spacecraft’s motion.

The data directories:

With Compton-Getting

hvset_tabular_ram_cg_single

hvset_tabular_ram_cg_year1

hvset_tabular_ram_cg_year2

hvset_tabular_ram_cg_year3

hvset_tabular_ram_cg_year4

hvset_tabular_ram_cg_year5

hvset_tabular_ram_cg_year6

hvset_tabular_ram_cg_year7

Without Compton-Getting

hvset_tabular_ram_single

hvset_tabular_ram_year1

hvset_tabular_ram_year2

hvset_tabular_ram_year3

hvset_tabular_ram_year4

hvset_tabular_ram_year5

hvset_tabular_ram_year6

hvset_tabular_ram_year7

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

Yearly Maps, Survival Probability Corrected, Antiram Direction

These maps include survival probability corrected data recorded from times when the aperture was pointed away from the hemisphere of the spacecraft’s motion.

The data directories:

With Compton-Getting

hvset_tabular_antiram_cg_single

hvset_tabular_antiram_cg_year1

hvset_tabular_antiram_cg_year2

hvset_tabular_antiram_cg_year3

hvset_tabular_antiram_cg_year4

hvset_tabular_antiram_cg_year5

hvset_tabular_antiram_cg_year6

hvset_tabular_antiram_cg_year7

Without Compton-Getting

hvset_tabular_antiram_single

hvset_tabular_antiram_year1

hvset_tabular_antiram_year2

hvset_tabular_antiram_year3

hvset_tabular_antiram_year4

hvset_tabular_antiram_year5

hvset_tabular_antiram_year6

hvset_tabular_antiram_year7

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

ENA Maps in Equatorial and Galactic Coordinates

These maps in equatorial and galactic coordinate systems are for the use of the broader astrophysical community:

hvset_tabular_ram_equatorial_single

hvset_tabular_antiram_cg_single

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

All Hi Data Directories

All IBEX Hi Data Directories

IBEX Lo Observing Energetic Neutral Atoms In a Lower Range of Energies

Plots and Data Directories

6-month Maps

These maps represent the data before any corrections are made for speed of spacecraft or survival probability.

The data directories:

lvset_h_single

lvset_h_map1

lvset_h_map2

lvset_h_map3

lvset_h_map4

lvset_h_map5

lvset_h_map6

lvset_h_map7

lvset_h_map8

lvset_h_map9

lvset_h_map10

lvset_h_map11

lvset_h_map12

lvset_h_map13

lvset_h_map14

Survival Probability Lookup Maps

Survival Probability Maps account for the loss (extinction) of ENAs due to radiation pressure, photoionization and ionization via charge exchange with solar wind protons.

The data directories:

lvset_h_tabular_single

lvset_h_tabular_map1

lvset_h_tabular_map2

lvset_h_tabular_map3

lvset_h_tabular_map4

lvset_h_tabular_map5

lvset_h_tabular_map6

lvset_h_tabular_map7

lvset_h_tabular_map8

lvset_h_tabular_map9

lvset_h_tabular_map10

lvset_h_tabular_map11

lvset_h_tabular_map12

lvset_h_tabular_map13

lvset_h_tabular_map14

Note: Survival probability correction procedures are documented in Appendix B in McComas et al. 2017.

All Lo Data Directories

All IBEX Lo Data Directories

Calculation Notes for Users to Combine Multiple Maps:

Combining different maps is done by accounting for the statistical uncertainties and time exposure weighting. Below is an example of combining three different maps.
ENA Exposure times for the three ENA maps: tau1, tau2, tau3;
ENA fluxes for the three ENA maps: flux1, flux2, flux3;
ENA flux variances for the three ENA maps: var1, var2, var3;
We now calculate the weights from the exposure times as,
wt1=tau1/(tau1+tau2+tau3)
wt2=tau2/(tau1+tau2+tau3)
wt3=tau3/(tau1+tau2+tau3)
Combined fluxes and propagated variances are then determined using:
combined_flux=flux1*wt1 + flux2*wt2 + flux3*wt3
combined_var=var1*(wt1)^2 + var2*(wt2)^2 + var3*(wt3)^2