Infrared Polarization in the Direction to the Galactic Center (original) (raw)

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Abstract

Infrared polarimetric observations were made in the K-band (2.2 μm) for 15 discrete sources and at 10 positions in the diffuse component distributed within 20' from the galactic center. For the discrete sources, photometric measurements were also made in I' J, H, K, L', and M bands. The amplitudes of polarization PK(%) of the discrete sources are linearly proportional to the color excesses E(H – K). The position angles of the polarization also change systematically with H – K, showing a jump at H – K = 1.0 mag. We interpret this as a change in the magnetic field configuration at the corresponding distance (≳5 kpc), Polarizations of the diffuse component are fairly uniform in the inner 30 pc of the galactic center, being indicative that the polarization is generated preferentially outside the central core. Adopting E(H – K) as a distance scale, the nature of the interstellar polarization is inferred along the line of sight to the galactic center.

Publication:

Publications of the Astronomical Society of Japan

Pub Date:

March 1983

DOI:

10.1093/pasj/35.1.101

Bibcode:

1983PASJ...35..101K

Keywords: