Probing Magnetic Fields in Protostars with near-IR Polarimetry

Barbara Whitney

University of Wisconsin-Madison

High-Resolution Observations (IRAS 04302+2247)

Data from Lucas & Roche (1997)

K-bandd = 140 pc0.3” resolution

Model for IRAS 04302+2247

Whitney & Wolff (2002)

K-bandd = 140 pc0.3” resolution

K-band polarization maps, no B-field

Pl = -6.9% PV = 0Integrated polarization:

Axial field (along z)

Pl = +2.7% PV = 0Integrated:

Whitney & Wolff 2002

Galli-Shu + toroid field

B j = exp[-z/a](Br2 + Bq

2)1/2

V = 6%Pl = Q = -8%

Galli-Shu + toroid field

Integrated:

Galli-Shu + toroid field

B j = exp[-z/a](b rcyl)-1.5 (Br2 + Bq

2)1/2

V = 3%Pl = Q = -16%

Galli-Shu + toroid field

Integrated: