Composite images of PDS 70 in pseudo color. The left panel shows previous ALMA observations at 0.87 mm, and the right panel shows new ALMA observations at 3 mm. The composite image combines millimeter/submillimeter continuum images with ALMA (red), an infrared continuum image from W. M. Keck Observatory (green), and an optical image of a hydrogen emission line taken with the VLT (blue). The images show that the dust emissions observed with ALMA form a ring-like structure outside the planets detected by Keck and the VLT. At a wavelength of 3 mm, the dust emission can be seen prominently concentrated in the northwest direction (upper right of the image). Credit: ALMA (ESO/NAOJ/NRAO), W. M. Keck Observatory, VLT (ESO), K. Doi (MPIA)
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