From: NASA HQ
Posted: Monday, September 27, 2010
WASHINGTON -- NASA will host a media teleconference at 1 p.m. EDT, on Wednesday, Sept. 29, to discuss new information about the boundary of our solar system obtained from the agency's Interstellar Boundary Explorer (IBEX) spacecraft.
The briefing participants are:
- Arik Posner, IBEX program scientist, Heliophysics Division, Science Mission Directorate, NASA Headquarters in Washington
- Nathan Schwadron, IBEX science operations lead and associate professor at the University of New Hampshire in Durham
- David McComas, IBEX principal investigator and assistant vice president of the Space Science and Engineering Division at Southwest Research Institute in San Antonio
- Merav Opher, associate professor, George Mason University in Fairfax, Va.
Reporters can receive dial-in information by sending an email to JD Harrington at email@example.com. Requests must include reporter's name, affiliation, and telephone number.
Audio of the teleconference will be streamed live at: http://www.nasa.gov/newsaudio
At the beginning of the briefing, related images will be available online at: http://www.nasa.gov/ibex
Comparisons of the Interstellar Magnetic Field Directions obtained from the IBEX Ribbon and Interstellar Polarizations
Priscilla C. Frisch, B-G Andersson, Andrei Berdyugin, Herbert O. Funsten, Mario Magalhaes, David J. McComas, Vilppu Piirola, Nathan A. Schwadron, Jonathan D. Slavin, Sloane J. Wiktorowicz Comments: Accepted for publication in the Astrophysical Journal. 25 pages, 5 figures
Subjects: Galaxy Astrophysics (astro-ph.GA)
Variations in the spatial configuration of the interstellar magnetic field (ISMF) near the Sun can be constrained by comparing the ISMF direction at the heliosphere found from the Interstellar Boundary Explorer spacecraft (IBEX) observations of a 'Ribbon' of energetic neutral atoms (ENAs), with the ISMF direction derived from optical polarization data for stars within ~40 pc. Using interstellar polarization observations towards ~30 nearby stars within 90 deg of the heliosphere nose, we find that the best fits to the polarization position angles are obtained for a magnetic pole directed towards ecliptic coordinates of lambda, beta 263 deg, 37 deg (or galactic coordinates of L,B 38 deg, 23deg), with uncertainties of +/- 35 deg, based on the broad minimum of the best fits and the range of data quality. This magnetic pole is 33 deg from the magnetic pole that is defined by the center of the arc of the ENA Ribbon. The IBEX ENA ribbon is seen in sightlines that are perpendicular to the ISMF as it drapes over the heliosphere. The similarity of the polarization and Ribbon directions for the local ISMF suggest that the local field is coherent over scale sizes of tens of parsecs. The ISMF vector direction is nearly perpendicular to the flow of local ISM through the local standard of rest, supporting a possible local ISM origin related to an evolved expanding magnetized shell. The local ISMF direction is found to have a curious geometry with respect to the cosmic microwave background dipole moment.
Other Related articles
- A possible generation mechanism for the IBEX ribbon from outside the heliosphere, astro-ph
- Scatter-free pickup ions beyond the heliopause as a model for the Interstellar Boundary Explorer (IBEX) ribbon, astro-ph
- Energetic Neutral Atoms: An Additional Source for Heliospheric Pickup Ions, SAO/NASA Astrophysics Data System (ADS)
- Can IBEX Identify Variations in the Galactic Environment of the Sun Using Energetic Neutral Atoms?, SAO/NASA Astrophysics Data System (ADS)
- Stability of a Pickup Ion Ring-beam Population in the Outer Heliosheath: Implications for the IBEX Ribbon, SAO/NASA Astrophysics Data System (ADS)
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