Implications of Interstellar Dust and Magnetic Field at the Heliosphere

TL;DR

This paper explores how interstellar dust and magnetic fields influence the heliosphere and potentially contaminate cosmic microwave background observations, revealing consistent magnetic field orientations and their implications.

Contribution

It provides new insights into the magnetic field structure near the heliosphere and its effects on interstellar dust and CMB foreground contamination.

Findings

Interstellar dust grains are deflected along magnetic field lines.

The magnetic field near the heliosphere is inclined by ~55-65 degrees to the galactic plane.

CMB dipole and quadrupole alignments relate to the heliosphere's magnetic environment.

Abstract

Tiny interstellar dust grains causing the polarization of light from the nearest stars are deflected sideways in the outer heliosheath regions, along with the interstellar magnetic field. Observations of optical polarization of stars beyond the heliosphere nose, suggest the direction of the upwind interstellar magnetic field is relatively constant. The polarizations of nearby stars and offset angle between HeI and HeI flowing into the heliosphere have position angles in galactic coordinates of 30- 40 deg, indicating a local magnetic field direction inclined by ~55 deg and ~65 deg, respectively, with respect to the galactic and ecliptic planes. The hot and cold poles of the measured Cosmic Microwave Background (CMB) dipole moment are nearly symmetric around the heliosphere nose direction, and the v^{22} quadrupole vector is directed towards the heliosphere nose. The area vectors of the CMB quadrupole and ocotopole moments are directed towards the band perpendicular to the ecliptic plane formed by the alternate locations for the 3 kHz emissions detected by Voyagers 1 and 2. In the upwind direction, the position angle of the null plane separating the CMB dipole hot and cold poles is nearly aligned with the interstellar magnetic field direction at the Sun. Heliospheric foreground contamination of the low-$\ell$ CMB modes now requires detailed study.