Holdship, J;
Viti, S;
Haworth, TJ;
Ilee, JD;
(2021)
Chemulator: Fast, accurate thermochemistry for dynamical models through emulation.
Astronomy & Astrophysics
, 653
, Article A76. 10.1051/0004-6361/202140357.
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Abstract
Context. Chemical modelling serves two purposes in dynamical models: accounting for the effect of microphysics on the dynamics and providing observable signatures. Ideally, the former must be done as part of the hydrodynamic simulation but this comes with a prohibitive computational cost that leads to many simplifications being used in practice. / Aims. We aim to produce a statistical emulator that replicates a full chemical model capable of solving the temperature and abundances of a gas through time. This emulator should suffer only a minor loss of accuracy when compared to a full chemical solver and would have a fraction of the computational cost allowing it to be included in a dynamical model. / Methods. The gas-grain chemical code UCLCHEM was updated to include heating and cooling processes, and a large dataset of model outputs from possible starting conditions was produced. A neural network was then trained to map directly from inputs to outputs. / Results. Chemulator replicates the outputs of UCLCHEM with an overall mean squared error (MSE) of 1.7 × 10−4 for a single time step of 1000 yr, and it is shown to be stable over 1000 iterations with an MSE of 3 × 10−3 on the log-scaled temperature after one timzze step and 6 × 10−3 after 1000 time steps. Chemulator was found to be approximately 50 000 times faster than the time-dependent model it emulates but can introduce a significant error to some models.
| Type: | Article |
|---|---|
| Title: | Chemulator: Fast, accurate thermochemistry for dynamical models through emulation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/202140357 |
| Publisher version: | https://doi.org/10.1051/0004-6361/202140357 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | astrochemistry / methods: numerical / methods: statistical / hydrodynamics |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10130876 |
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