An artist’s rendition of our heliosphere, showing the outward-flowing solar wind and the various boundary regions (Photo : NASA/IBEX/Adler Planetarium)
A mystical ribbon of particles surrounds the region of space between our solar system and interstellar space. Located at the edge of the heliosphere, it has baffled scientists as to what the nature and cause of such a cosmic phenomenon could be. A newly proposed "retention model" suggests that the ribbon is the result of charged particles escaping as neutral atoms.
The study, titled "Spatial Retention Of Ions Producing The IBEX Ribbon," was published Feb. 4 in The Astrophysical Journal.
IBEX stands for the Interstellar Boundary Explorer, which is the "first spacecraft designed to collect data across the entire sky about the heliosphere and its boundary," according to the mission statement on the IBEX website. IBEX measures particles instead of light, and detected a ribbon that surrounds the edge of our solar system.
The reason behind ribbon lies with energetic neutral atoms (ENAs) that the sun spits out. Some of the ENAs end up hitting neutral atoms in the heliopause region (the edge of the heliosphere) and become charged again. These ions then end up accumulating in the area around the magnetic field surrounding our solar system. Wherever the magnetic field is perpendicular to the motion of the recharged particles, some of the ones that get scattered lose their charge and reenter space as secondary ENAs - it's this process that creates the strange ribbon.
"The syrup you pour on a pancake piles up before slowly oozing out to the sides," IBEX principal investigator and assistant vice president of the SwRI Space Science and Engineering Division Dr. David McComas said.
"The secondary ENAs coming into the solar system after having been temporarily trapped in a region just outside the solar system do the same thing. As they pile up and get trapped or retained, they produce higher fluxes of ENAs from this region and form the bright ribbon seen by IBEX."