TY - JOUR
T1 - Following the interstellar magnetic field from the heliosphere into space with polarized starlight
AU - Frisch, P. C.
AU - Berdyugin, A. B.
AU - Piirola, V.
AU - Magalhaes, A. M.
AU - Seriacopi, D. B.
AU - Ferrari, T.
AU - Santos, F. P.
AU - Schwadron, N. A.
AU - Funsten, H. O.
AU - McComas, D. J.
AU - Heiles, C. E.
N1 - Funding Information:
This research has been supported by the NASA Explorer program through support for the IBEX mission and by the ERC Advanced Grant Hot-Mol ERC-2011-AdG-291659. AMM is grateful for support from FAPESP (grant no. 2010/19694-4) and CNP (Research Grant). DBS is grateful for support from CAPES (Phd scholarship). We are grateful to the Institute for Astronomy at the University of Hawaii (IfA) for the allocation of IfA time for observations at the T60 and UH88 telescopes, and to LNA, Brazil, for the allocation of observing time at the Observatorio do Pico dos Dias (OPD).
Publisher Copyright:
© Published under licence by IOP Publishing Ltd.
PY - 2016/11/22
Y1 - 2016/11/22
N2 - Starlight linearly polarized by aligned interstellar dust grains provides the necessary data for tracing the structure of the very local interstellar magnetic field (ISMF). Two methods have been developed to recover the ISMF direction from polarized starlight, using data from an ongoing polarization survey. Both methods rely on the probability distribution function for polarized light. Method 1 calculates the ISMF direction from polarization position angles regardless of the data accuracy, while Method 2 relies on high-probability data points. The ISMF direction Bibex recovered by Method 1 corresponds to the closest ISMF to the heliosphere, traced by the center of the IBEX Ribbon arc. Method 2 reveals a new direction for the more distant ISMF, B new, toward l=41.1° ± 4.1° and b= 25.8° ± 3.0°, which differs by 30.4° ± 5.6° from the IBEX ISMF direction. Polarizations of filament stars that are located within 25° of a pole of Bnew, where background polarizations would be minimal, show the highest statistical probabilities of tracing the filament ISMF. The IBEX ISMF direction orders the kinematics of interstellar clouds within 15 pc, and B new must therefore dominate beyond 15 pc. These new data are consistent with the location of the Sun in the rim of an expanding superbubble shell associated with the evolved Loop I superbubble.
AB - Starlight linearly polarized by aligned interstellar dust grains provides the necessary data for tracing the structure of the very local interstellar magnetic field (ISMF). Two methods have been developed to recover the ISMF direction from polarized starlight, using data from an ongoing polarization survey. Both methods rely on the probability distribution function for polarized light. Method 1 calculates the ISMF direction from polarization position angles regardless of the data accuracy, while Method 2 relies on high-probability data points. The ISMF direction Bibex recovered by Method 1 corresponds to the closest ISMF to the heliosphere, traced by the center of the IBEX Ribbon arc. Method 2 reveals a new direction for the more distant ISMF, B new, toward l=41.1° ± 4.1° and b= 25.8° ± 3.0°, which differs by 30.4° ± 5.6° from the IBEX ISMF direction. Polarizations of filament stars that are located within 25° of a pole of Bnew, where background polarizations would be minimal, show the highest statistical probabilities of tracing the filament ISMF. The IBEX ISMF direction orders the kinematics of interstellar clouds within 15 pc, and B new must therefore dominate beyond 15 pc. These new data are consistent with the location of the Sun in the rim of an expanding superbubble shell associated with the evolved Loop I superbubble.
UR - http://www.scopus.com/inward/record.url?scp=85007358347&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85007358347&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/767/1/012010
DO - 10.1088/1742-6596/767/1/012010
M3 - Conference article
AN - SCOPUS:85007358347
SN - 1742-6588
VL - 767
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012010
T2 - 15th Annual International Astrophysics Conference: The Science of Ed Stone: Celebrating his 80th Birthday, AIAC 2016
Y2 - 4 April 2016 through 8 April 2016
ER -