7 papers
Pair Discharges and Radio Emission from Millisecond-Pulsar and White-Dwarf Magnetospheres
Tuomo Salmi, Joonas Nättilä
Coherent radio emission is observed from compact astrophysical objects with relatively weak magnetic fields, including millisecond pulsars and white dwarfs, the latter being propos…
Pair Discharges and Radio Emission from Pulsar Magnetospheres
Joonas Nättilä, Tuomo Salmi
Radio pulsars can power their coherent radio emission through intermittent plasma discharges in magnetospheric gaps. The nonlinear coupling between particle acceleration, quantum e…
Machine-Learning Characterization of Intermittency in Relativistic Pair Plasma Turbulence: Single and Double Sheet Structures
Trung Ha, Joonas Nättilä, Jordy Davelaar +1
The physics of turbulence in magnetized plasmas remains an unresolved problem. The most poorly understood aspect is intermittency -- spatio-temporal fluctuations superimposed on th…
aweSOM: a CPU/GPU-accelerated Self-organizing Map and Statistically Combined Ensemble Framework for Machine-learning Clustering Analysis
Trung Ha, Joonas Nättilä, Jordy Davelaar
We introduce aweSOM, an open-source Python package for machine learning (ML) clustering and classification, using a Self-organizing Maps (SOM) algorithm that incorporates CPU/GPU a…
Scale Statistics of Current Sheets in Relativistic Collisionless Plasma Turbulence
Roberto F. Serrano, Joonas Nättilä, Vladimir Zhdankin
We analyze distributions of the spatial scales of coherent intermittent structures -- current sheets -- obtained from fully kinetic, two-dimensional simulations of relativistic pla…
Radiative plasma simulations of black hole accretion flow coronae in the hard and soft states
Joonas Nättilä
Stellar-mass black holes in x-ray binary systems are powered by mass transfer from a companion star. The accreted gas forms an accretion disk around the black hole and emits x-ray…