Area 1: An Overview of Evidence for the National Approach to Professional Learning in Education

This report reviews published literature on the way that countries around the globe have organised and systematised professional learning for teachers in a time of curriculum change. It first reviews country specific literature and then presents evidence on the organisation of professional learning from more general literature, which is more concerned with improvements in practice. All literature used is either from peer-reviewed journals or from academic books. The literature was found by using scholarly search engines, searching under various terms indicating professional learning. In this way literature was uncovered that will be used to support or to question the approach that the Welsh Government takes towards professional learning in education

A new diabatization scheme for direct quantum dynamics : procrustes diabatization

We present a new scheme for diabatizing electronic potential energy surfaces, for use within the recently implemented direct-dynamics grid-based (DD-GB) class of computational nuclear quantum dynamics methods (DD-SM and DD-MCTDH), called Procrustes diabatization. Calculations on the well-studied molecular systems LiF and the butatriene cation, using both Procrustes diabatization and the previously implemented propagation and projection diabatization schemes, have allowed detailed comparisons to be made which indicate that the new method combines the best features of the older approaches; it generates smooth surfaces which cross at the correct molecular geometries, reproduces interstate couplings accurately and hence allows the correct modelling of non-adiabatic dynamics

Radiative cooling of swept up gas in AGN-driven galactic winds and its implications for molecular outflows

We recently used hydro-chemical simulations to demonstrate that molecular outflows observed in luminous quasars can be explained by molecule formation within the AGN wind. However, these simulations cover a limited parameter space, due to their computational cost. We have therefore developed an analytic model to follow cooling in the shocked ISM layer of an AGN wind. We explore different ambient densities ($1-10^{4} \, \rm{cm}^{-3}$), density profile slopes ($0-1.5$), AGN luminosities ($10^{44}-10^{47} \, \rm{erg} \, \rm{s}^{-1}$), and metallicities ($0.1-3 \rm{Z}_{\odot}$). The swept up gas mostly cools within ~1 Myr. Based on our previous simulations, we predict that this gas would produce observable molecular outflows. The instantaneous momentum boost initially increases as the outflow decelerates. However, it reaches a maximum of $\approx$20, due to work done against the gravitational potential. The predicted time-averaged observational estimate of the molecular outflow momentum boost reaches a maximum of $\approx1-2$, partly due to our assumed molecular fraction, 0.2, but also because the instantaneous and observational, time-averaged definitions are not equivalent. Thus recent observational estimates of order unity momentum boosts do not necessarily rule out energy-driven outflows. Finally, we find that dust grains are likely to re-form by accretion of metals after the shocked ISM layer has cooled, assuming that a small fraction of dust grains swept up after this layer has cooled are able to mix into the cool phase, and assuming that grain growth remains efficient in the presence of the strong AGN radiation field. This would enable rapid molecule formation, as assumed in our models.Comment: 22 pages, 16 figures (including appendices). Accepted for publication in MNRA

The origin of fast molecular outflows in quasars: molecule formation in AGN-driven galactic winds

We explore the origin of fast molecular outflows that have been observed in Active Galactic Nuclei (AGN). Previous numerical studies have shown that it is difficult to create such an outflow by accelerating existing molecular clouds in the host galaxy, as the clouds will be destroyed before they can reach the high velocities that are observed. In this work, we consider an alternative scenario where molecules form in-situ within the AGN outflow. We present a series of hydro-chemical simulations of an isotropic AGN wind interacting with a uniform medium. We follow the time-dependent chemistry of 157 species, including 20 molecules, to determine whether molecules can form rapidly enough to produce the observed molecular outflows. We find H$_2$ outflow rates up to 140 M$_\odot$ yr$^{-1}$, which is sensitive to density, AGN luminosity, and metallicity. We compute emission and absorption lines of CO, OH and warm (a few hundred K) H$_2$ from the simulations in post-processing. The CO-derived outflow rates and OH absorption strengths at solar metallicity agree with observations, although the maximum line of sight velocities from the model CO spectra are a factor $\approx$2 lower than is observed. We derive a CO (1-0) to H$_2$ conversion factor of $\alpha_{\rm{CO} (1-0)}$ = 0.13 M$_\odot$ (K km s$^{-1}$ pc$^2$)$^{-1}$, 6 times lower than is commonly assumed in observations of such systems. We find strong emission from the mid-infrared lines of H$_2$. The mass of H$_2$ traced by this infrared emission is within a few per cent of the total H$_2$ mass. This H$_2$ emission may be observable by JWST.Comment: 30 pages, 21 figures (including appendices), resubmitted to MNRAS following referee's report. Some results have changed from the previous version, in particular for warm H2 emission (see Figs. 5 and 13

The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies

We present a series of hydrodynamic simulations of isolated galaxies with stellar mass of $10^{9} \, \rm{M}_{\odot}$. The models use a resolution of $750 \, \rm{M}_{\odot}$ per particle and include a treatment for the full non-equilibrium chemical evolution of ions and molecules (157 species in total), along with gas cooling rates computed self-consistently using the non-equilibrium abundances. We compare these to simulations evolved using cooling rates calculated assuming chemical (including ionisation) equilibrium, and we consider a wide range of metallicities and UV radiation fields, including a local prescription for self-shielding by gas and dust. We find higher star formation rates and stronger outflows at higher metallicity and for weaker radiation fields, as gas can more easily cool to a cold (few hundred Kelvin) star forming phase under such conditions. Contrary to variations in the metallicity and the radiation field, non-equilibrium chemistry generally has no strong effect on the total star formation rates or outflow properties. However, it is important for modelling molecular outflows. For example, the mass of H$_{2}$ outflowing with velocities $> 50 \, \rm{km} \, \rm{s}^{-1}$ is enhanced by a factor $\sim 20$ in non-equilibrium. We also compute the observable line emission from CII and CO. Both are stronger at higher metallicity, while CII and CO emission are higher for stronger and weaker radiation fields respectively. We find that CII is generally unaffected by non-equilibrium chemistry. However, emission from CO varies by a factor of $\sim 2 - 4$. This has implications for the mean $X_{\rm{CO}}$ conversion factor between CO emission and H$_{2}$ column density, which we find is lowered by up to a factor $\sim 2.3$ in non-equilibrium, and for the fraction of CO-dark molecular gas.Comment: 26 pages, 16 figures, accepted for publication in MNRAS. Minor changes relative to v

Direct quantum dynamics using grid-based wavefunction propagation and machine-learned potential energy surfaces

We describe a method for performing nuclear quantum dynamics calculations using standard, grid-based algorithms, including the multi configurational time-dependent Hartree (MCTDH) method, where the potential energy surface (PES) is calculated “on-the-fly”. The method of Gaussian process regression (GPR) is used to construct a global representation of the PES using values of the energy at points distributed in molecular configuration space during the course of the wavepacket propagation. We demonstrate this direct dynamics approach for both an analytical PES function describing 3-dimensional proton transfer dynamics in malonaldehyde, and for 2- and 6-dimensional quantum dynamics simulations of proton transfer in salicylaldimine. In the case of salicylaldimine we also perform calculations in which the PES is constructed using Hartree-Fock calculations through an interface to an ab initio electronic structure code. In all cases, the results of the quantum dynamics simulations are in excellent agreement with previous simulations of both systems, yet do not require prior fitting of a PES at any stage. Our approach (implemented in a development version of the Quantics package) opens a route to performing accurate quantum dynamics simulations via wavefunction propagation of many-dimensional molecular systems in a direct and efficient manner

Non-equilibrium chemistry and cooling in the diffuse interstellar medium - I. Optically thin regime

An accurate treatment of the multiphase interstellar medium (ISM) in hydrodynamic galaxy simulations requires that we follow not only the thermal evolution of the gas, but also the evolution of its chemical state, including its molecular chemistry, without assuming chemical (including ionisation) equilibrium. We present a reaction network that can be used to solve for this thermo-chemical evolution. Our model follows the evolution of all ionisation states of the 11 elements that dominate the cooling rate, along with important molecules such as H2 and CO, and the intermediate molecular species that are involved in their formation (20 molecules in total). We include chemical reactions on dust grains, thermal processes involving dust, cosmic ray ionisation and heating and photochemical reactions. We focus on conditions typical for the diffuse ISM, with densities of 10^-2 cm^-3 < nH < 10^4 cm^-3 and temperatures of 10^2 K < T < 10^4 K, and we consider a range of radiation fields, including no UV radiation. In this paper we consider only gas that is optically thin, while paper II considers gas that becomes shielded from the radiation field. We verify the accuracy of our model by comparing chemical abundances and cooling functions in chemical equilibrium with the photoionisation code Cloudy. We identify the major coolants in diffuse interstellar gas to be CII, SiII and FeII, along with OI and H2 at densities nH > 10^2 cm^-3. Finally, we investigate the impact of non-equilibrium chemistry on the cooling functions of isochorically or isobarically cooling gas. We find that, at T < 10^4 K, recombination lags increase the electron abundance above its equilibrium value at a given temperature, which can enhance the cooling rate by up to two orders of magnitude. The cooling gas also shows lower H2 abundances than in equilibrium, by up to an order of magnitude.Comment: 26 pages, 13 figures, accepted for publication in MNRAS. Corrected an error in figure 2. Supplementary material can be found at http://noneqism.strw.leidenuniv.n

Improved on-the-fly MCTDH simulations with many-body-potential tensor decomposition and projection diabatisation

We have recently demonstrated how potential energy surface (PES) interpola- tion methods such as kernel ridge regression (KRR), can be combined with accu- rate wavefunction time-propagation methods, specifically the multi-configuration time- dependent Hartree (MCTDH) method, to generate a new “on-the-fly” MCTDH scheme (DD-MCTDH) which does not require the pre-fitting of the PES which is normally re- quired by MCTDH. Specifically, we have shown how our DD-MCTDH strategy can be used to model non-adiabatic dynamics in a 4-mode/2-state model of pyrazine, with ab initio electronic structure calculations performed directly during propagation, requir- ing around 100 hours of computer wall-time. In this Article, we show how the efficiency and accuracy of DD-MCTDH can be dramatically improved further still by: (i) using systematic tensor decompositions of the KRR PES, and (ii) using a novel scheme for di- abatisation within the framework of configuration interaction (CI) methods which only requires local adiabatic electronic states, rather than non-adiabatic coupling matrix el- ements. The result of these improvements is that our latest version of DD-MCTDH can perform a 12-mode/2-state simulation of pyrazine, with PES evaluations at CAS level, in just 29-90 hours on a standard desktop computer; this work therefore represents an enormous step towards direct quantum dynamics with MCTDH

The multiphase circumgalactic medium traced by low metal ions in EAGLE zoom simulations

We explore the circumgalactic metal content traced by commonly observed low ion absorbers, including C II, SiII, SiIII, SiIV, and MgII. We use a set of cosmological hydrodynamical zoom simulations run with the EAGLE model and including a non-equilibrium ionization and cooling module that follows 136 ions. The simulations of z ≈ 0.2 L* (M200= 1011.7- 1012.3M⊙) haloes hosting star-forming galaxies and group-sized (M200= 1012.7- 1013.3M⊙) haloes hosting mainly passive galaxies reproduce key trends observed by the COS-Halos survey - low ion column densities show 1) little dependence on galaxy-specific star formation rate, 2) a patchy covering fraction indicative of 104K clumps with a small volume filling factor, and 3) a declining covering fraction as impact parameter increases from 20-160kpc. Simulated Si II, Si III, Si IV, CII, and C III column densities show good (mostly within 0.3 dex) agreement with observations, while MgII is under-predicted. Low ions trace a significant metal reservoir, ≈108M⊙, residing primarily at 10-100kpc from star-forming and passive central galaxies. These clumps preferentially flow inwards and most will accrete onto the central galaxy within the next several Gyr, while a small fraction are entrained in strong outflows. A multiphase structure describes the inner CGM ( 0.5R200) tracing virial temperature gas around L* galaxies. Our simulations support previous ionization models indicating that cloud covering factors decline while densities and pressures show little decline with increasing impact parameter (typically < 0.3 dex from 40 to 160 kpc). We find the cool clumps have lower pressures than the ambient medium they are embedded in, and discuss that numerical effects within the hydrodynamic solver likely play a role. © 2018 The Author(s)

Unravelling the photoprotection properties of mycosporine amino acid motifs

Photoprotection from harmful ultraviolet (UV) radiation exposure is a key problem in modern society. Mycosporine like amino acids found in fungi, cyanobacteria, macroalgae, phytoplankton and humans, are already presenting a promising form of natural photoprotection in sunscreen formulations. Using time-resolved transient electronic absorption spectroscopy and guided by complementary ab initio calculations, we help to unravel how the core structures of these molecules perform under UV irradiation. Through such detailed insight into the relaxation mechanisms of these ubiquitous molecules, we hope to inspire new thinking in developing next generation sun protecting molecules