The Interstellar Magnetic Field Close to the Sun II

Abstract

A key indicator of the galactic environment of the Sun is provided by the magnetic field in the interstellar medium (ISM), which influences the shape of the heliosphere. The direction of the nearby interstellar magnetic field (ISMF) is determined from starlight polarized in the ISM. The local ISMF direction is found from the ISMF direction that provides the best fit to the polarization position angles of nearby stars, using weighted fits to the data. New polarization observations are included in the analysis. The best-fitting ISMF is close to the magnetic field direction traced by the center of the Ribbon of energetic neutral atoms, discovered by the Interstellar Boundary Explorer spacecraft. Both the magnetic field and kinematics of the local ISM are consistent with a scenario where the local ISM is a fragment of the Loop I superbubble. An ordered component of the local ISMF is found in a region where PlanetPol data show that polarization increases with distance. It extends to within 8 parsecs of the Sun and implies a weak curvature in the nearby ISMF. Variations from the ordered component indicate turbulence of +/-23 deg. The local ISMF is generally uniform in direction over spatial scales of 8-200 parsecs so that it appears similar to interarm magnetic fields. The best-fitting ISMF direction also agrees with the position of tail-in spatial asymmetries in GeV-TeV galactic cosmic rays. The peculiar geometrical relation between the CMB dipole moment, the heliosphere nose, and local ISMF is supported by these new results. Radiative torques are not likely to play a role in grain alignment for these polarizations.

Accepted by the Astrophysical Journal. Changes from version 1 include addition of an appendix and fixing typos

References in corpus (13)

• Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
• Tracing Magnetic Fields with Aligned Grains
• The Structure of the Local Interstellar Medium V: Electron Densities
• Discovery of Localized Regions of Excess 10-TeV Cosmic Rays
• The Efficiency of Grain Alignment in Dense Interstellar Clouds: A Reassessment of Constraints from Near Infrared Polarization
• A New Model For The Loop-I (The North Polar Spur) Region
• The Boundary Conditions of the Heliosphere: Photoionization Models Constrained by Interstellar and In Situ Data
• Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation
• The Interstellar H Flow: Updated Analysis of SOHO/SWAN Data
• Angle-dependent radiative grain alignment; Confirmation of a magnetic field - radiation anisotropy angle dependence on the efficiency of interstellar grain alignment
• Circular polarization survey of intermediate polars I. Northern targets in the range 17h<R.A.<23h
• Simulations of Mixed Morphology Supernova Remnants With Anisotropic Thermal Conduction
• Implications of Interstellar Dust and Magnetic Field at the Heliosphere

Cited by in corpus (37)

• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Modeling the magnetized Local Bubble from dust data
• Anisotropy of TeV Cosmic Rays and the Outer Heliospheric Boundaries
• Constraining the properties of the magnetic turbulence in the Geminga region using HAWC $\gamma$-ray data
• Reconciling cosmic ray diffusion with Galactic magnetic field models
• A high-sensitivity polarimeter using a ferro-electric liquid crystal modulator
• Astrophysical Shrapnel: Discriminating Among Near-Earth Stellar Explosion Sources of Live Radioactive Isotopes
• The Local Bubble: a magnetic veil to our Galaxy
• Charting the Interstellar Magnetic Field causing the Interstellar Boundary Explorer (IBEX) Ribbon of Energetic Neutral Atoms
• A radio-polarisation and rotation measure study of the Gum Nebula and its environment
• A Ground-Based Albedo Upper Limit for HD 189733b from Polarimetry
• Constraints on Axion-like Particles from a Hard $X$-ray Observation of Betelgeuse
• The interstellar cloud surrounding the Sun: a new perspective
• The Galactic Magneto-Ionic Medium Survey: Moments of the Faraday Spectra
• The return of the bow shock
• The intrinsic and interstellar broadband linear polarization of nearby FGK dwarfs
• Anisotropic Cosmic Ray Diffusion and its Implications for Gamma-Ray Astronomy
• Local Bubble contribution to the 353-GHz dust polarized emission
• Cosmic Ray Small Scale Anisotropies and Local Turbulent Magnetic Fields
• Is Voyager 1 Inside an Interstellar Flux Transfer Event?
• Large-Scale Cosmic-Ray Anisotropy as a Probe of Interstellar Turbulence
• Electromagnetic forces on a relativistic spacecraft in the interstellar medium
• TeV Cosmic-Ray Anisotropy from the Magnetic Field at the Heliospheric Boundary
• Magnetic fields and cosmic ray anisotropies at TeV energies
• Evidence for an interstellar dust filament in the outer heliosheath
• Interstellar Dust Close to the Sun
• Measurements and implications of cosmic ray anisotropies from TeV to trans-EeV energies
• Probing Oort Cloud and Local Interstellar Medium Properties via Dust Produced in Cometary Collisions
• The Origin of the Cluster of Local Interstellar Clouds
• Investigating the IBEX Ribbon Structure a Solar Cycle Apart
• Observation of TeV-PeV cosmic ray anisotropy with IceCube, IceTop and AMANDA
• Detecting Pulsar Polarization below 100 MHz with the Long Wavelength Array
• An analytical model for the magnetic field in the thick shell of Galactic bubbles with uniform initial conditions
• Connecting the interstellar magnetic field at the heliosphere to the Loop I superbubble
• TeV-PeV Cosmic-Ray Anisotropy and Local Interstellar Turbulence
• MHD flows at astropauses and in astrotails
• Cosmic ray propagation in the interstellar magnetic fields