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Modelling the early evolution of magnetic flux ropes (MFRs) in the solar atmosphere is crucial for understanding their destabilization and eruption mechanism. Identifying the relevant magnetic field lines in simulation data, however, is not straightforward. In previous work an extraction and tracking method was developed to facilitate this task. Here, we present the corresponding graphical user interface (GUI), called GUITAR (GUI for Tracking and Analysing flux Ropes), with the aim to offer a variety of tools to the community for identifying and tracking MFRs. The starting point is a map of a selected proxy parameter for MFRs, e.g., a map of the twist-parameter Tw, current density, etc. We showcase how the GUITAR tools can be used to disentangle a multi-MFR system and facilitate in-depth analysis of their properties and evolution by applying them on a time-dependent data-driven magnetofrictional model (TMFM) simulation of solar active region AR12473. We show the MFR extraction using Tw maps, together with targeted use of mathematical morphology algorithms and discuss the evolution of the system.

Stars falling too close to massive black holes in the centers of galaxies can be torn apart by the strong tidal forces. Simulating the subsequent feeding of the black hole with disrupted material has proved challenging because of the range of timescales involved. Here we report a set of simulations that capture the relativistic disruption of the star, followed by 1 yr of evolution of the returning debris stream. These reveal the formation of an expanding asymmetric bubble of material extending to hundreds of au—an outflowing Eddington envelope with an optically thick inner region. Such outflows have been hypothesized as the reprocessing layer needed to explain optical/UV emission in tidal disruption events but never produced self-consistently in a simulation. Our model broadly matches the observed light curves with low temperatures, faint luminosities, and line widths of 10,000–20,000 km s ^−1 .

Stars approaching supermassive black holes can be tidally disrupted. Despite being expected to emit X-rays, tidal disruption events (TDEs) have been largely observed in optical bands, which is poorly understood. In this Letter, we simulate the tidal disruption of a 1 M _⊙ main-sequence star on an eccentric ( e = 0.95) orbit with a periapsis distance 1 or 5 times smaller than the tidal radius ( β = 1 or 5) using general relativistic smoothed particle hydrodynamics. We follow the simulation for up to 1 yr postdisruption. We show that accretion disks in eccentric TDEs are masked by unbound material outflowing at ∼10,000 km s ^−1 . Assuming electron scattering opacity, this material would be visible as a ∼100 au photosphere at ∼10 ^4 K, in line with observations of candidate TDEs.

The Solar MAgnetic Connection HAUS1 tool (Solar-MACH) is an open-source tool completely written in Python that derives and visualizes the spatial configuration and solar magnetic connection of different observers (i.e., spacecraft or planets) in the heliosphere at different times. For doing this, the magnetic connection in the interplanetary space is obtained by the classic Parker Heliospheric Magnetic Field (HMF). In close vicinity of the Sun, a Potential Field Source Surface (PFSS) model can be applied to connect the HMF to the solar photosphere. Solar-MACH is especially aimed at providing publication-ready figures for the analyses of Solar Energetic Particle events (SEPs) or solar transients such as Coronal Mass Ejections (CMEs). It is provided as an installable Python package (listed on PyPI and conda-forge), but also as a web tool at solar-mach.github.io that completely runs in any web browser and requires neither Python knowledge nor installation. The development of Solar-MACH is open to everyone and takes place on GitHub, where the source code is publicly available under the BSD 3-Clause License. Established Python libraries like sunpy and pfsspy are utilized to obtain functionalities when possible. In this article, the Python code of Solar-MACH is explained, and its functionality is demonstrated using real science examples. In addition, we introduce the overarching SERPENTINE project, the umbrella under which the recent development took place.

Solar Energetic Particles (SEPs) are charged particles accelerated within the solar atmosphere or the interplanetary space by explosive phenomena such as solar flares or Coronal Mass Ejections (CMEs). Once injected into the interplanetary space, they can propagate towards Earth, causing space weather related phenomena. For their analysis, interplanetary in situ measurements of charged particles are key. The recently expanded spacecraft fleet in the heliosphere not only provides much-needed additional vantage points, but also increases the variety of missions and instruments for which data loading and processing tools are needed. This manuscript introduces a series of Python functions that will enable the scientific community to download, load, and visualize charged particle measurements of the current space missions that are especially relevant to particle research as time series or dynamic spectra. In addition, further analytical functionality is provided that allows the determination of SEP onset times as well as their inferred injection times. The full workflow, which is intended to be run within Jupyter Notebooks and can also be approachable for Python laymen, will be presented with scientific examples. All functions are written in Python, with the source code publicly available at GitHub under a permissive license. Where appropriate, available Python libraries are used, and their application is described.

PyThea is a newly developed open-source Python software package that provides tools to reconstruct coronal mass ejections (CMEs) and shocks waves in three dimensions, using multi-spacecraft remote-sensing observations. In this article, we introduce PyThea to the scientific community and provide an overview of the main functionality of the core software package and the web application. This package has been fully built in Python, with extensive use of libraries available within this language ecosystem. PyThea package provides a web application that can be used to reconstruct CMEs and shock waves. The application automatically retrieves and processes remote-sensing observations, and visualizes the imaging data that can be used for the analysis. Thanks to PyThea, the three-dimensional reconstruction of CMEs and shock waves is an easy task, with final products ready for publication. The package provides three widely used geometrical models for the reconstruction of CMEs and shocks, namely, the graduated cylindrical shell (GCS) and an ellipsoid/spheroid model. It also provides tools to process the final fittings and calculate the kinematics. The final fitting products can also be exported and reused at any time. The source code of PyThea package can be found in GitHub and Zenodo under the GNU General Public License v3.0. In this article, we present details for PyThea‘s python package structure and its core functionality, and we show how this can be used to perform three-dimensional reconstruction of coronal mass ejections and shock waves.

We use numerical simulations of circumplanetary disks to determine the boundary between disks that are radially truncated by the tidal potential and those where gas escapes the Hill sphere. We consider a model problem, in which a coplanar circumplanetary disk is resupplied with gas at an injection radius smaller than the Hill radius. We evolve the disk using the Phantom smoothed particle hydrodynamics code until a steady state is reached. We find that the most significant dependence of the truncation boundary is on the disk aspect ratio H / R . Circumplanetary disks are efficiently truncated for H / R ≲ 0.2. For H / R ≃ 0.3, up to about half of the injected mass, depending on the injection radius, flows outward through the decretion disk and escapes. As expected from analytic arguments, the conditions ( H / R and Shakura–Sunyaev α ) required for tidal truncation are independent of planet mass. A simulation with larger α = 0.1 shows stronger outflow than one with α = 0.01, but the dependence on transport efficiency is less important than variations of H / R . Our results suggest two distinct classes of circumplanetary disks: tidally truncated thin disks with dust-poor outer regions, and thicker actively decreting disks with enhanced dust-to-gas ratios. Applying our results to the PDS 70 c system, we predict a largely truncated circumplanetary disk, but it is possible that enough mass escapes to support an outward flow of dust that could explain the observed disk size.

We report a detailed analysis of interplanetary flux ropes observed at Venus and subsequently at Earth's Lagrange L1 point between June 15 and 17, 2012. The observation points were separated by about 0.28 AU in radial distance and 5° in heliographic longitude at this time. The flux ropes were associated with three coronal mass ejections (CMEs) that erupted from the Sun on June 12–14, 2012 (SOL2012-06-12, SOL2012-06-13, and SOL2012-06-14). We examine the CME–CME interactions using in-situ observations from the almost radially aligned spacecraft at Venus and Earth, as well as using heliospheric modeling and imagery. The June 14 CME reached the June 13 CME near the orbit of Venus and significant interaction occurred before they both reached Earth. The shock driven by the June 14 CME propagated through the June 13 CME and the two CMEs coalesced, creating the signatures of one large, coherent flux rope at L1. We discuss the origin of the strong interplanetary magnetic fields related to this sequence of events, the complexity of interpreting solar wind observations in the case of multiple interacting CMEs, and the coherence of the flux ropes at different observation points.

Amorphous formulation technologies to improve oral absorption of poorly soluble active pharmaceutical ingredients (APIs) have become increasingly prevalent. Currently, polymer-based amorphous formulations manufactured by spray drying, hot melt extrusion (HME), or co-precipitation are most common. However, these technologies have challenges in terms of the successful stabilization of poor glass former compounds in the amorphous form. An alternative approach is mesoporous silica, which stabilizes APIs in non-crystalline form via molecular adsorption inside nano-scale pores. In line with these considerations, two poor glass formers, haloperidol and carbamazepine, were formulated as polymer-based solid dispersion via HME and with mesoporous silica, and their stability was compared under accelerated conditions. Changes were monitored over three months with respect to solid-state form and dissolution. The results were supported by solid-state nuclear magnetic resonance spectroscopy (SS-NMR) and scanning electron microscopy (SEM). It was demonstrated that mesoporous silica was more successful than HME in the stabilization of the selected poor glass formers. While both drugs remained non-crystalline during the study using mesoporous silica, polymer-based HME formulations showed recrystallization after one week. Thus, mesoporous silica represents an attractive technology to extend the formulation toolbox to poorly soluble poor glass formers.

In this article, techniques for separating mixtures of insoluble compounds are discussed with respect to the small quantities found in laboratory preparations, as opposed to industrial quantities. The techniques include separations based on density, surface area and differences in particle size. Also discussed are simple apparatus, readily available in the laboratory or from commercial suppliers, for achieving these techniques. [ABSTRACT FROM AUTHOR]

The structure, synthesis and magnetic properties of three new complex cobalt hydroxyl oxalates are presented, showing a modification of the 2-D double layer hydroxide structure. Co12(OH)18(ox)3(pip) [ox = oxalate, C2O42−; pip = piperazine, C4N2H10] (1), is essentially built from brucite-like layers with a one ninthdepletion of the octahedral sites and a preservation of a trigonal crystallographic symmetry. ACo28(OH)43(ox)6Br2(H2O)2[A = Na (2), K (3)] are similarly composed of a brucite-like layer with three nineteenthsdepletion of octahedral sites, again preserving a trigonal symmetry. Both 2and 3show a small degree of structural disorder within the framework. All of these compounds have alternating layers of a mineral-like metal hydroxide structure and a metal oxalate coordination network, with the depletion in the hydroxyl layers being templated by the coordination network. Magnetic studies of 1reveal a metamagnetic character, with the onset of an antiferromagnetic phase below Tc= 23.5 K (H= 0 G), and a first order antiferromagnet to metamagnet transition at Hc= 500–1000 G (T= 20–6 K). Compound 3shows a more conventional ferrimagnetic ordering below 33(±1) K with a small coercive field of 107(±5) G at 10 K. [ABSTRACT FROM AUTHOR]

Crystals of a cobalt(ii) 3-amino-1,2,4-triazolate; Co2Cl(C2N4H3)3, 1 can be formed from a hydrothermal synthesis. X-Ray crystallography shows an extended 3-dimensional network structure within a hexagonal space group with a = 9.9655(7) and c = 7.7523(7) Å. The data reveal an orientational disorder to the ligand. Structural considerations suggest that the ligand orientation is strongly correlated in 1-dimension, but the nature and length scale of the 2-dimensional order is not obvious. The structure is discussed in terms of three key structural models, two of which are crystallographically ordered, while the third is disordered in 2-dimensions. The effect of ligand orientation on the network topology has profound effects on the expected magnetic behaviour, with the two fully ordered models having either antiferromagnetic or ferrimagnetically ordered ground states. The magnetism of 1 is complex. It shows an antiferromagnetically coupled paramagnetic phase above ∼5.3 K. Below ∼4.5 K we see a ferrimagnetically ordered state (Hcoer = 50 Oe, Mrem = 1830 Oe cm3 mol−1, Msat = 3450 Oe cm3 mol−1 at 2 K). In the intermediate temperature range 4.5 to 5.3 K we see unusual behaviour with evidence of rapid, low-energy relaxation of the magnetisation. The unusual relationship between the structure and the magnetism of 1 is discussed in detail. [ABSTRACT FROM AUTHOR]

This paper presents splash, a publicly available interactive visualisation tool for Smoothed Particle Hydrodynamics (SPH) simulations. Visualisation of SPH data is more complicated than for grid-based codes because the data are defined on a set of irregular points and therefore requires a mapping procedure to a two dimensional pixel array. This means that, in practise, many authors simply produce particle plots which offer a rather crude representation of the simulation output. Here we describe the techniques and algorithms which are utilised in splash in order to provide the user with a fast, interactive and meaningful visualisation of one, two and three dimensional SPH results. [ABSTRACT FROM AUTHOR]

Six new iron arsenate framework structures, Fe2As2O7·2H2O, [Fe6As8O32H4]2−(1,4-butanediamininium2+)·2H2O, [Fe4As6O22H2]2−(piperazinium2+), [Fe5As5O24H4]2−(piperazinium2+)·2H2O, [Fe6As7O31H5]2−(dabco2+) and LiFeAsO4OH have been synthesised under hydrothermal conditions. Incorporation of the amine cation templates leads to more open framework geometries and, in contrast to iron phosphates which have topologies based on PO4 tetrahedra, the iron arsenate structures typically contain protonated As(O,OH)4 units. The magnetic properties of the iron arsenates studied show Curie–Weiss behaviours with maxima in the χ(T) vs.T plots in the range 10–50 K. [ABSTRACT FROM AUTHOR]