Observation of interstellar polarization at 2.2 and 3.8 microns
T. Nagata;
ApJ, 1990, 348, L13
ABSTRACT:Interstellar linear polarization has been observed in the K (2.2 micron) and L-prime (3.8 micron) bands for 30 stars.
The K band
results generally agree with the previous measurements.
The L-prime
polarization, obtained for the first time, is larger for most stars than Serkowski's
(1974) and Wilking's (1980) empirical formulas predict.
From these
observations, a power-law dependence of polarization of about wavelength exp-2 in
the wavelength range of 1.25-2.2 microns is proposed; this dependence is
similar to that of interstellar extinction.
The decrease of polarization
from K to L-prime is even slower than this power-law.
This might be also
similar to the extinction law, but confirmation by further observations is
necessary.
KEYWORDS: infrared astronomy, interstellar matter, linear polarization, interstellar extinction, line spectra, power series
PERSOKEY:polarisation, nir, extinction, ,
CODE: nagata90