| 19th of October 2015 |
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| An ATCA survey of debris disks at 7 millimeters |
| by Sarah Maddison (Swinburne University) |
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Ricci et al.
(2015) use the Australia Telescope Compact Array to survey five nearby debris disks at a wavelength of 7 mm, including the famous edge-on disk of β
Pictoris, shown above, which is known to host at least one planet. These radio images result predominantly from thermal emission that is produced when the dusty disk surrounding the star absorbs the starlight and re-emits at radio wavelengths. The dust grains observed in debris disks are thought to be produced by collisions between km-sized "planetesimals", or comets and asteroids, leftover from the planet formation process. Because of their extremely faint emission, the km-sized planetesimals cannot be directly observed. However, information on their physical and dynamical properties can be extracted from the size distribution of the smaller dust grains, and radio emission from debris disks can be used to determine the size distribution of the grains in these disk. - The image shows the
debris disk around β Pictoris. Reference: Ricci, Maddison, Wilner, MacGregor, Ubach, Carpenter, Testi, 2015, ApJ, in press |