Near-infrared multiwavelength imaging polarimetry of the low-mass proto-stellar object HL Tauri
(Research Note)
Murakawa, K., Oya, S., Pyo, T.-S., and Ishii, M.
A&A, 492, pg.731–734 (2008)
Abstract
We present the JHK-band high-resolution polarimetric images of the low-mass proto-stellar object HL Tau using the adaptive opticsequipped
CIAO instrument on the Subaru telescope. Our polarization images show a butterfly-shaped polarization disk with an
~0".9 + 3".0 extension. In the nebula, where polarization vectors are centro-symmetrically aligned, the polarization is as high as PJ
~ 30%,
PH ~ 42%, and PK ~ 55%. On the other hand, low polarizations of P < 3% in the J, H, and K bands and a low color excess ratio
of EJ−H/EH−K = 1.1 compared to the standard cloud value of 1.75 are detected towards the central star. We estimated the upper
limit of the grain sizes amax to be 0.4 μm in the nebula and >~
0.7 μm in the line of sight towards the central star. Our high-resolution
polarimetric data, which spatially resolves the polarization disk, provides us with important information about grain growth in the
region close to the central star.
You can get this publication ...