* Astronomy

Blobrana · L

RE: IBEX Mission

Blobrana · L

A Major Step Forward in Explaining the Ribbon in Space Discovered by NASAs IBEX Mission

724750main1_1_AP_IBEX_combined_1.74-670.jpg

The vast edges of our solar system - the boundary at the edge of our heliosphere where material streaming out from the sun interacts with the galactic material - is essentially invisible. It emits no light and no conventional telescope can see it. However, particles from inside the solar system bounce off this boundary and neutral atoms from that collision stream inward. Those particles can be observed by instruments on NASAs Interstellar Boundary Explorer (IBEX). Since those atoms act as fingerprints for the boundary from which they came, IBEX can map that boundary in a way never before done. In 2009, IBEX saw something in that map that no one could explain: a vast ribbon dancing across this boundary that produced many more energetic neutral atoms than the surrounding areas.
Read more

Blobrana · L

IBEX: Observing the Sun's Horizon

The Interstellar Boundary Explorer, or IBEX, is the first mission designed to map the entire region of the boundary of our Solar System. As charged particles from the Sun, called the "solar wind," flow outward well beyond the orbits of the planets, they collide with the material between the stars, called the "interstellar medium" (ISM). These interactions create energetic neutral atoms (ENAs), particles with no charge that move very quickly. This region emits no light that can be collected by conventional telescopes so, instead, IBEX, measures the particles that happen to be travelling inward from the boundary. IBEX contains two detectors designed to collect and measure ENAs, providing data about the mass, location, direction of origin, and energy of these particles. From these data, maps of the boundary are created. IBEX's sole, focused science objective is to discover the nature of the interactions between the solar wind and the interstellar medium at the edge of our Solar System.

Blobrana · L

IBEX - New Observations of Interstellar Matter - Briefing Materials

NASA will host a Science Update to discuss new analysis from NASA's Interstellar Boundary Explorer (IBEX) spacecraft of material from outside our solar system and the interstellar boundary region that surrounds our home in space.
Read more

Blobrana · L

Back in October 2009, we announced IBEXs first major science results, including the observation of what has become known as the "IBEX Ribbon." Since that time, IBEX has been detecting energetic neutral atoms coming from the boundary of our Solar System and from regions of our Earths magnetosphere, and we have periodically updated the IBEX website with information on these topics.
Read more

Blobrana · L

A NASA spacecraft has uncovered the solar system's "nose," which points in the direction our sun is moving through the Milky Way galaxy, astronomers say.

In 2009 IBEX revealed a vast ribbon of atoms snaking its way along the solar system's edge. While intriguing, this ribbon was preventing astronomers from mapping the entire heliosphere.
Now Nathan Schwadron of the University of New Hampshire and his team have finally been able to digitally subtract the intense emissions given off by this mysterious ribbon, revealing the heliosphere's nose. This feature, like the bow of a ship, appears at the leading edge of the windsock-like heliosphere.
Read more

Blobrana · L

IBEX Ribbon

Blobrana · L

RE: IBEX Mission

Blobrana · L

IBEX ribbon

Blobrana · L

Title: A possible generation mechanism for the IBEX ribbon from outside the heliosphere
Authors: S. Grzedzielski (1), M. Bzowski (1), A. Czechowski (1), H.O. Funsten (2), D.J. McComas (3), N.A. Schwadron (4) ((1) Space Research Centre PAS, Warsaw, Poland, (2) Los Alamos National Lab, Los Alamos NM, (3) Southwest Research Institute, San Antonio TX, (4) Boston University, Boston MA)

The brightest and most surprising feature in the first all-sky maps of Energetic Neutral Atoms (ENA) emissions (0.2-6 keV) produced by the Interstellar Boundary Explorer (IBEX) is an almost circular ribbon of a ~140{\deg} opening angle, centred at (l,b) = (33{\deg}, 55{\deg}), covering the part of the celestial sphere with the lowest column densities of the Local Interstellar Cloud (LIC). We propose a novel interpretation of the IBEX results based on the idea of ENA produced by charge-exchange between the neutral H atoms at the nearby edge of the LIC and the hot protons of the Local Bubble (LB). These ENAs can reach the Sun's vicinity because of very low column density of the intervening LIC material. We show that a plane-parallel or slightly curved interface layer of contact between the LIC H atoms (n_H = 0.2 cm^-3, T = 6000-7000 K) and the LB protons (n_p = 0.005 cm^-3, T ~ 10^6 K), together with indirect contribution coming from multiply-scattered ENAs from the LB, may be able to explain both the shape of the ribbon and the observed intensities provided that the edge is < (500-2000) AU away, the LIC proton density is (correspondingly) < (0.04-0.01) cm^-3, and the LB contains ~1% of non-thermal protons over the IBEX energy range. If this model is correct, then IBEX, for the first time, has imaged in ENAs a celestial object from beyond the confines of the heliosphere and can directly diagnose the plasma conditions in the LB.

Read more (487kb, PDF)