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Discs around young planets, so-called circumplanetary discs (CPDs), are essential for planet growth, satellite formation, and planet detection. We study the millimetre and centimetre emission from accreting CPDs by using the simple $alpha$ disc model. We find that it is easier to detect CPDs at shorter radio wavelengths (e.g. $lambdalesssim$ 1 mm). For example, if the system is 140 pc away from us, deep observations (e.g. 5 hours) at ALMA Band 7 (0.87 mm) are sensitive to as small as 0.03 lunar mass of dust in CPDs. If the CPD is around a Jupiter mass planet 20 AU away from the host star and has $alphalesssim 0.001$, ALMA can detect this disc when it accretes faster than $10^{-10} M_{odot}/yr$. ALMA can also detect the minimum mass sub-nebulae disc if such a disc exists around a young planet in YSOs. However, to distinguish the embedded compact CPD from the circumstellar disc material, we should observe circumstellar discs with large gaps/cavities using the highest resolution possible. We also calculate the CPD fluxes at VLA bands, and discuss the possibility of detecting radio emission from jets/winds launched in CPDs. Finally we argue that, if the radial drift of dust particles is considered, the drifting timescale for millimetre dust in CPDs can be extremely short. It only takes 10$^2$-10$^{3}$ years for CPDs to lose millimetre dust. Thus, for CPDs to be detectable at radio wavelengths, mm-sized dust in CPDs needs to be replenished continuously, or the disc has a significant fraction of micron-sized dust or a high gas surface density so that the particle drifting timescale is long, or the radial drift is prevented by other means (e.g. pressure traps).
We investigated the formation and evolution of satellite systems in a cold, extended circumplanetary disc around a 10 $M_{rm{Jupiter}}$ gas giant which was formed by gravitational instability at 50,AU from its star. The disc parameters were from a 3D
Like the magnetised planets in our Solar System, magnetised exoplanets should emit strongly at radio wavelengths. Radio emission directly traces the planetary magnetic fields and radio detections can place constraints on the physical parameters of th
We present three-dimensional simulations with nested meshes of the dynamics of the gas around a Jupiter mass planet with the JUPITER and FARGOCA codes. We implemented a radiative transfer module into the JUPITER code to account for realistic heating
Protoplanetary disc systems observed at radio wavelengths often show excess emission above that expected from a simple extrapolation of thermal dust emission observed at short millimetre wavelengths. Monitoring the emission at radio wavelengths can b
Two planetary mass objects in the far outer Solar System --- collectively referred to here as Planet X --- have recently been hypothesized to explain the orbital distribution of distant Kuiper Belt Objects. Neither planet is thought to be exceptional