RH 1.5D: a massively parallel code for multi-level radiative transfer with partial frequency redistribution and Zeeman polarisation

Abstract

The emergence of three-dimensional magneto-hydrodynamic (MHD) simulations of stellar atmospheres has sparked a need for efficient radiative transfer codes to calculate detailed synthetic spectra. We present RH 1.5D, a massively parallel code based on the RH code and capable of performing Zeeman polarised multi-level non-local thermodynamical equilibrium (NLTE) calculations with partial frequency redistribution for an arbitrary amount of chemical species. The code calculates spectra from 3D, 2D or 1D atmospheric models on a column-by-column basis (or 1.5D). While the 1.5D approximation breaks down in the cores of very strong lines in an inhomogeneous environment, it is nevertheless suitable for a large range of scenarios and allows for faster convergence with finer control over the iteration of each simulation column. The code scales well to at least tens of thousands of CPU cores, and is publicly available. In the present work we briefly describe its inner workings, strategies for convergence optimisation, its parallelism, and some possible applications.

6 pages, 3 figures. A&A in press. Updated version reflects changes in latest proofs

References in corpus (20)

• The stellar atmosphere simulation code Bifrost
• Radiative MHD simulation of sunspot structure
• Numerical simulation of the three-dimensional structure and dynamics of the non-magnetic solar chromosphere
• The Stagger-grid: A Grid of 3D Stellar Atmosphere Models - I. Methods and General Properties
• The formation of IRIS diagnostics II. The formation of the Mg II h&k lines in the solar atmosphere
• Spectroscopic Signatures of Convection in the Spectrum of Procyon. Fundamental Parameters and Iron Abundance
• 3D Hydrodynamical Simulations of Surface Convection in Red Giant Stars. Impact on spectral line formation and abundance analysis
• The formation of IRIS diagnostics I. A quintessential model atom of Mg II and general formation properties of the Mg II h&k lines
• Magnetic flux emergence in granular convection: Radiative MHD simulations and observational signatures
• Twisted flux tube emergence from the convection zone to the corona
• The formation of IRIS diagnostics. III. Near-ultraviolet Spectra and Images
• PORTA: A three-dimensional multilevel radiative transfer code for modeling the intensity and polarization of spectral lines with massively parallel computers
• The quiet solar atmosphere observed and simulated in NaD1
• Spicule-like structures observed in 3D realistic MHD simulations
• Improvements to Stellar Structure Models, Based on a Grid of 3D Convection Simulations. I. $T(\tau )$-Relations
• Fast approximation of angle-dependent partial redistribution in moving atmospheres
• Energy transport, overshoot, and mixing in the atmospheres of M-type main- and pre-main-sequence objects
• 3D LTE spectral line formation with scattering in red giant stars
• 3-D non-LTE radiative transfer effects in Fe I lines: II. Line formation in 3-D radiation hydrodynamic simulations
• Sulphur abundances from the SI near-infrared triplet at 1045 nm

Cited by in corpus (80)

• On the generation of solar spicules and Alfvénic waves
• Non-LTE oxygen line formation in 3D hydrodynamic model stellar atmospheres
• Bombs and flares at the surface and lower atmosphere of the Sun
• The Formation of IRIS diagnostics. IV. The Mg II triplet lines as a new diagnostic for lower chromospheric heating
• Continuum Enhancements in the Ultraviolet, the Visible and the Infrared during the X1 flare on 2014 March 29
• Intermittent reconnection and plasmoids in UV bursts in the low solar atmosphere
• Ellerman bombs and UV bursts: transient events in chromospheric current sheets
• 3D NLTE analysis of the most iron-deficient star, SMSS0313-6708
• Data-driven Radiative Hydrodynamic Modeling of the 2014 March 29 X1.0 Solar Flare
• Investigating the response of loop plasma to nanoflare heating using RADYN simulations
• Transverse Wave Induced Kelvin-Helmholtz Rolls in Spicules
• IRIS Observations of the Mg II h & k Lines During a Solar Flare
• Partial redistribution in 3D non-LTE radiative transfer in solar atmosphere models
• Chromospheric Extension of the MURaM Code
• IRIS observations of short-term variability in moss associated with transient hot coronal loops
• A parameter study for modeling MgII h and k emission during solar flares
• The Formation of IRIS Diagnostics. VII. The Formation of the OI 135.56 nm Line in the Solar Atmosphere
• Modeling Mg II h, k and Triplet Lines at Solar Flare Ribbons
• The Lightweaver Framework for NLTE Radiative Transfer in Python
• Sunrise III: Overview of Observatory and Instruments
• Solar Ellerman Bombs in 1-D Radiative Hydrodynamics
• RADYN simulations of non-thermal and thermal models of Ellerman bombs
• The Sun at millimeter wavelengths -- II. Small-scale dynamic events in ALMA Band 3
• Non-LTE Calculations of the Fe I 6173 Å Line in a Flaring Atmosphere
• Semi-empirical model atmospheres for the chromosphere of the sunspot penumbra and umbral flashes
• Bridging the Gap: Capturing the Ly$\alpha$ Counterpart of a Type-II Spicule and its Heating Evolution with VAULT2.0 and IRIS Observations
• Efficient Calculation of Non-Local Thermodynamic Equilibrium Effects in Multithreaded Hydrodynamic Simulations of Solar Flares
• Multi thermal atmosphere of a mini solar flare during magnetic reconnection observed with IRIS
• Investigation of Relationship Between High-Energy X-ray Sources and Photospheric and Helioseismic Impacts of X1.8 Solar Flare of October 23, 2012
• Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
• Umbral chromospheric fine structure and umbral flashes modelled as one: the corrugated umbra
• Modelling of Mg II lines in solar prominences
• ALMA and IRIS Observations of the Solar Chromosphere I: an On-Disk Type II Spicule
• Prospects of Detecting Non-thermal Protons in Solar Flares via Lyman Line Spectroscopy: Revisiting the Orrall-Zirker Effect
• The non-LTE formation of the Fe I 6173 A line in the solar atmosphere
• Mg ii h&k spectra of an enhanced network region simulated with the MURaM-ChE code. Results using 1.5D synthesis
• Evidence of multithermal nature of spicular downflows. Impact on solar atmospheric heating
• Non-thermal electrons from solar nanoflares
• The Formation of IRIS Diagnostics. IX. The Formation of the C I 135.58 Line in the Solar Atmosphere
• The Response of the Lyman-Alpha Line in Different Flare Heating Models
• Formal Solutions for Polarized Radiative Transfer. IV. Numerical Performances in Practical Problems
• Statistical Study of Chromospheric Evaporation in Impulsive Phase of Solar Flares
• Diagnostic of Homologous Solar Surge Plasma as observed by IRIS and SDO
• Spatio-temporal evolution of Hanle and Zeeman synthetic polarization in a chromospheric spectral line
• Chromospheric Heating from Local Magnetic Growth and Ambipolar Diffusion Under Non-Equilibrium Conditions
• Response of SDO/HMI observables to heating of the solar atmosphere by precipitating high-energy electrons
• A Statistical Study of IRIS Observational Signatures of Nanoflares and Non-thermal Particles
• The dynamic chromosphere: pushing the boundaries of observations and models
• Statistical analysis of the Si I 6560.58 Å line observed by CHASE
• Chromospheric emission from nanoflare heating in RADYN simulations
• Opacity distribution functions for stellar spectra synthesis
• Constraining the systematics of (acoustic) wave heating estimates in the solar chromosphere
• An approximate recipe of chromospheric radiative losses for solar flares
• Formation of H$\epsilon$ in the solar atmosphere
• Solar Flare Irradiance: Observations and Physical Modeling
• Non-Equilibrium Spectrum Formation Affecting Solar Irradiance
• Radiative Hydrodynamic Simulations of the Spectral Characteristics of Solar White-light Flares
• On the Importance of Ca II Photoionisation by the Hydrogen Lyman Transitions in Solar Flare Models
• The key role of solar dynamics in the chromospheric Hanle polarization
• Stratification of canopy magnetic fields in a plage region. Constraints from a spatially-regularized weak-field approximation method
• Evaluation of different recipes for chromospheric radiative losses in solar flares
• An Assessment of and Solution to the Intensity Diffusion Error Intrinsic to Short-Characteristic Radiative Transfer Methods
• Infrared diagnostics of the solar magnetic field with Mg I 12 $\mu$m lines: forward-model results
• High Resolution Observations of the Low Atmospheric Response to Small Coronal Heating Events in an Active Region Core
• Comparison of chromospheric diagnostics in a 3D model atmosphere: H$\alpha$ linewidth and mm continua
• Ca ii 854.2 nm in an enhanced network region simulated with MURaM-ChE
• Non-LTE Calculations of the Mg I 12.32 $\mu$m Line in a Flaring Atmosphere
• Solar Atmosphere Radiative Transfer Model Comparison based on 3D MHD simulations
• Connecting Atmospheric Properties and Synthetic Emission of Shock Waves Using 3D RMHD Simulations of Quiet Sun
• Observations of pores and surrounding regions with CO 4.66 μm lines by BBSO/CYRA
• Jacobian-Free Newton-Krylov method for multilevel NLTE radiative transfer problems
• EMISSA: Exploring millimetre indicators of solar-stellar activity III. Comparison of Ca II indices and millimetre continua in a 3D model atmosphere
• Accelerated particle beams in a 3D simulation of the quiet Sun. Lower atmospheric spectral diagnostics
• Young M dwarfs flare activity model: Towards better exoplanetary atmospheric characterisation
• Small-scale energetic phenomena in Hε: Ellerman bombs, UV bursts, and small flares
• Multi-height Identification of Sausage and Fluting Eigenmodes in a Solar Pore
• Effects of spatial resolution on inferences of atmospheric quantities from simulations
• Cause of chromospheric opposite polarity intrusions discovered in Sunrise III/SCIP data: MURaM-ChE simulations point to twisted flux ropes
• Irregular grids for 3D NLTE radiative transfer in stellar atmospheres
• Revisiting the Spectral Features of Ellerman Bombs and UV Bursts. I. Radiative Hydrodynamic Simulations