SUBARU/HICIAO HK_S imaging of LKHα 330 - multi-band detection of the gap and spiral-like structures

We present H- and K_s-bands observations of the LkHα 330 disk with a multi-band detection of the large gap and spiral-like structures. The morphology of the outer disk (r ∼0^′′ . 3) at PA=0–45^◦ and PA=180–290^◦ are likely density wave-induced spirals and comparison between our observational results and simulations suggests a planet formation. We have also investigated the azimuthal profiles at the ring and the outer-disk regions as well as radial profiles in the directions of the spiral-like structures and semi-major axis. Azimuthal analysis shows a large variety in wavelength and implies that the disk has non-axisymmetric dust distributions. The radial profiles in the major-axis direction (PA=271^◦) suggest that the outer region (r ≥ 0^′′ . 25) may be influenced by shadows of the inner region of the disk. The spiral-like directions (PA=10^◦ and 230^◦) show different radial profiles, which suggests that the surfaces of the spiral-like structures are highly flared and/or have different dust properties. Finally, a color-map of the disk shows a lack of an outer eastern region in the H-band disk, which may hint the presence of an inner object that casts a directional shadow onto the disk.