122 research outputs found
Sub-Arcsecond Near-Infrared Images of Massive Star Formation Region NGC 6334 V
We present high spatial resolution (0\farcs3) polarimetric images in the
and bands and direct images in the and bands of the NGC 6334
V infrared nebulae. The images show complex structures including the
multi-shells and various knots in the nebulae. The appearances and colors of
the eastern and western nebulae differ considerably. Our polarization images
also show differences between the illuminating sources of the nebulae: the
eastern nebula is illuminated by a deeply embedded mid-infrared source, KDJ 4,
and the western nebula by our newly detected near-infrared source, WN-A1. The
degree of polarization of the nebulae is very large, up to 70% at and 60%
at , which is consistent with a single scattering of near-infrared radiation
from each source at the walls of the mass outflows
Microwave-magnetic-field-induced magnetization excitation and assisted switching of antiferromagnetically coupled magnetic bilayer with perpendicular magnetization
Subaru near infrared coronagraphic images of T Tauri
High angular resolution near-infrared (JHK) adaptive optics images of T Tau were obtained with the infrared camera Coronagraphic Imager with Adaptive Optics (CIAO) mounted on the 8.2m Subaru Telescope in 2002 and 2004. The images resolve a complex circumstellar structure around a multiple system. We resolved T Tau Sa and Sb as well as T Tau N and S. The estimated orbit of T Tau Sb indicates that it is probably bound to T Tau Sa. The K band flux of T Tau S decreased by ˜ 1.7 Jy in 2002 November compared with that in 2001 mainly because T Tau Sa became fainter. The arc-like ridge detected in our near-infrared images is consistent with what is seen at visible wavelengths, supporting the interpretation in previous studies that the arc is part of the cavity wall seen relatively pole-on. Halo emission is detected out to ˜2\u27\u27from T Tau N. This may be light scattered off the common envelope surrounding the T Tauri multiple system
Polarimetric Imaging of Large Cavity Structures in the Pre-transitional Protoplanetary Disk around PDS 70: Observations of the disk
We present high resolution H-band polarized intensity (PI; FWHM = 0."1: 14
AU) and L'-band imaging data (FWHM = 0."11: 15 AU) of the circumstellar disk
around the weak-lined T Tauri star PDS 70 in Centaurus at a radial distance of
28 AU (0."2) up to 210 AU (1."5). In both images, a giant inner gap is clearly
resolved for the first time, and the radius of the gap is ~70 AU. Our data show
that the geometric center of the disk shifts by ~6 AU toward the minor axis. We
confirm that the brown dwarf companion candidate to the north of PDS 70 is a
background star based on its proper motion. As a result of SED fitting by Monte
Carlo radiative transfer modeling, we infer the existence of an optically thick
inner disk at a few AU. Combining our observations and modeling, we classify
the disk of PDS 70 as a pre-transitional disk. Furthermore, based on the
analysis of L'-band imaging data, we put an upper limit mass of companions at
~30 to ~50MJ within the gap. Taking account of the presence of the large and
sharp gap, we suggest that the gap could be formed by dynamical interactions of
sub-stellar companions or multiple unseen giant planets in the gap.Comment: accepted by APJ
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