IBEX's Enigmatic Ribbon in the sky and its many possible sources

McComas, D. J.; Lewis, W. S.; Schwadron, N. A.

doi:10.1002/2013rg000438

Cited by 89 publications

(46 citation statements)

References 126 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Illustrated in Figure 14 are sky maps for the five IBEX-Hi energy steps, produced by combining all 10 maps produced in IBEX's first 5 years of observations (McComas et al 2014b). These sky maps currently represent the "best" average ENA flux measurements observed at ∼1 AU, in the heliospheric reference frame, and the IBEX data have been corrected in both energy and angle for the Compton-Getting effect (McComas et al , 2012b.…”

Section: Global Observations: Ibex Measurementsmentioning

confidence: 99%

Faltering Steps Into the Galaxy: The Boundary Regions of the Heliosphere

Zank

2015

Annu. Rev. Astron. Astrophys.

125

View full text Add to dashboard Cite

The interaction of the heliosphere with the local interstellar medium (LISM) results in a complicated series of boundary regions. The Voyager 1 and 2 spacecraft are exploring these distant boundaries in situ, as is the Interstellar Boundary Explorer from 1 AU, which measures energetic neutral atoms created in the distant reaches of the heliosphere and LISM. Lyman-α absorption and backscatter measurements also probe the structure and physics of the interface of the heliosphere and LISM. We survey the suite of observations, the underlying theory, and the resulting models that describe the boundary regions of the solar wind and LISM. 449

show abstract

Section: Global Observations: Ibex Measurementsmentioning

confidence: 99%

Faltering Steps Into the Galaxy: The Boundary Regions of the Heliosphere

Zank

2015

Annu. Rev. Astron. Astrophys.

125

View full text Add to dashboard Cite

show abstract

“…While the origin of the ribbon is still under debate (see McComas et al 2014b for a recent review), the globally distributed flux is assumed to originate largely from the IHS (e.g., Gruntman et al 2001;Fahr et al 2007;Heerikhuisen et al 2008;Prested et al 2008;Schwadron et al 2011; for OHS sources, see e.g., Izmodenov et al 2009;Prested et al 2010;Opher et al 2013;Desai et al 2014;Zirnstein et al 2014). Analyses of IBEX allsky ENA spectra revealed that the majority of the plasma producing ENAs observed over the IBEX energy range can be represented by kappa functions, with the kappa index varying between 1.5 and 2.5 (Livadiotis et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Using Kappa Functions to Characterize Outer Heliosphere Proton Distributions in the Presence of Charge-Exchange

Zirnstein

McComas

2015

ApJ

Self Cite

View full text Add to dashboard Cite

Kappa functions have long been used in the analysis and modeling of suprathermal particles in various space plasmas. In situ observations of the supersonic solar wind show its distribution contains a cold ion core and powerlaw tail, which is well-represented by a kappa function. In situ plasma observations by Voyager, as well as observations of energetic neutral atom (ENA) spectra by the Interstellar Boundary Explorer (IBEX), showed that the compressed and heated inner heliosheath (IHS) plasma beyond the termination shock can also be represented by a kappa function. IBEX exposes the IHS plasma properties through the detection of ENAs generated by chargeexchange in the IHS. However, charge-exchange modifies the plasma as it flows through the IHS, and makes it difficult to ascertain the parent proton distribution. In this paper we investigate the evolution of proton distributions, initially represented by a kappa function, that experience losses due to charge-exchange in the IHS. In the absence of other processes, it is no longer representable by a single kappa function due to the energydependent, charge-exchange process. While one can still fit a kappa function to the evolving proton distribution over limited energy ranges, this yields fitting parameters (pseudo-density, pseudo-temperature, pseudo-kappa index) that depend on the energy range of the fit. We discuss the effects of fitting a kappa function to the IHS proton distribution over limited energy ranges, its dependence on the initial proton distribution properties at the termination shock, and implications for understanding the observations.

show abstract

“…Additional discussion of the secondary ENA process and other ENA populations is found in Izmodenov et al (2009) and Chalov et al (2010). For a recent review of processes that may create the IBEX ribbon, see McComas et al (2014).…”

Section: Introductionmentioning

confidence: 99%

Low Energy Neutral Atoms From the Heliosheath

Fuselier

Allegrini

Bzowski

et al. 2014

ApJ

Self Cite

View full text Add to dashboard Cite

In the heliosheath beyond the termination shock, low energy (<0.5 keV) neutral atoms are created by charge exchange with interstellar neutrals. Detecting these neutrals from Earth's orbit is difficult because their flux is reduced substantially by ionization losses as they propagate from about 100 to 1 AU and because there are a variety of other signals and backgrounds that compete with this weak signal. Observations from IBEX-Lo and -Hi from two opposing vantage points in Earth's orbit established a lower energy limit of about 0.1 keV on measurements of energetic neutral atoms (ENAs) from the heliosphere and the form of the energy spectrum from about 0.1 to 6 keV in two directions in the sky. Below 0.1 keV, the detailed ENA spectrum is not known, and IBEX provides only upper limits on the fluxes. However, using some assumptions and taking constraints on the spectrum into account, we find indications that the spectrum turns over at an energy between 0.1 and 0.2 keV.

show abstract

IBEX's Enigmatic Ribbon in the sky and its many possible sources

Cited by 89 publications

References 126 publications

Faltering Steps Into the Galaxy: The Boundary Regions of the Heliosphere

Faltering Steps Into the Galaxy: The Boundary Regions of the Heliosphere

Using Kappa Functions to Characterize Outer Heliosphere Proton Distributions in the Presence of Charge-Exchange

Low Energy Neutral Atoms From the Heliosheath

Contact Info

Product

Resources

About