TESTING GALACTIC MAGNETIC FIELD MODELS USING NEAR-INFRARED POLARIMETRY

Journal Article · Tue Apr 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/749/1/71· OSTI ID:22020473

Pavel, Michael D; Clemens, D P

This work combines new observations of NIR starlight linear polarimetry with previously simulated observations in order to constrain dynamo models of the Galactic magnetic field. Polarimetric observations were obtained with the Mimir instrument on the Perkins Telescope in Flagstaff, AZ, along a line of constant Galactic longitude (l = 150 Degree-Sign ) with 17 pointings of the 10' Multiplication-Sign 10' field of view between -75 Degree-Sign < b < 10 Degree-Sign , with more frequent pointings toward the Galactic midplane. A total of 10,962 stars were photometrically measured and 1116 had usable polarizations. The observed distribution of polarization position angles with Galactic latitude and the cumulative distribution function of the measured polarizations are compared to predicted values. While the predictions lack the effects of turbulence and are therefore idealized, this comparison allows significant rejection of A0-type magnetic field models. S0 and disk-even halo-odd magnetic field geometries are also rejected by the observations, but at lower significance. New predictions of spiral-type, axisymmetric magnetic fields, when combined with these new NIR observations, constrain the Galactic magnetic field spiral pitch angle to -6 Degree-Sign {+-} 2 Degree-Sign .

• OSTI ID: 22020473
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 749; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AXIAL SYMMETRY
COSMOLOGICAL MODELS
COSMOLOGY
DISTRIBUTION FUNCTIONS
DUSTS
INCLINATION
MAGNETIC FIELDS
POLARIMETRY
POLARIZATION
RADIANT HEAT TRANSFER
STARS
TELESCOPES