Computational Astrophysics

This new Transnational Access Activities will provide new opportunities for European researchers to access free of charge complex computational astrophysical simulations, models and tools to simulate, compare, and analyse X-ray and gamma-ray data. The offered access will stimulate and enhance the knowledge of high-energy astrophysics across Europe. It will be of great interest to relatively inexperienced users in small institutes, and to observers that aim to gain new knowledge in computational astrophysics to model their data. The selection process will ensure that the best scientific use of the TNA is made and that the selected TNA site matches the needs of the user. The support will be provided by at least one person, for several hours a day, by means of tutorials, hands-on sessions, and models tailored to the users’ needs. After the visit, a point of contact at the TNA site will still be available for follow-up discussions.

All visits are fully supported for travel and subsistence expenses.


Visits can be carried out at the following infrastructures:

Department of Astronomy of the University of Geneva

The Department of Astronomy of the University of Geneva has a long experience in space missions, in particular with high-energy astrophysics missions, such as Integral. It further participates in activities related to the ESA L-class ATHENA mission, and other future space projects (e.g., XRISM, THESEUS, SPICA, eXTP, LISA, K-EUSO, etc). Scientific activities in high-energy astrophysics are focused around active galactic nuclei, X-ray binaries, galaxy clusters, and stars. The Department of Astronomy participated in the ASTRO-H/HITOMI mission, and was hosting the HITOMI European Science Support Center, and is now in the XRISM mission, expected to be launched in 2021 (in the midst of the period covered by this project).
Services currently offered by the infrastructure: the Department of Astronomy started the development of a multi-purpose tool to simulate X-ray interactions with matter. The code, called RefleX is publicly available. RefleX can simulate a vast variety of geometrical configurations and physical conditions; it is able to produce spectra, images and light curves. Visitors will be able to get familiar with the RefleX tool and will receive support into applying RefleX to their science case, including in the case of advanced usage, like the generation of Xspec models.


INAF – Astronomical Observatory of Trieste

The Astronomical Observatory of Trieste (OATs) is one of the laboratories of the INAF. INAF-OATs has a long experience in carrying out cosmological hydrodynamical simulations of galaxy clusters and in comparing the thermodynamical and chemodynamical properties of the simulated intra-cluster medium (ICM) with X-ray observations. The group has developed software packages to extract mock X-ray observations of galaxy clusters from numerical simulations. This expertise has been recently applied to generate mocks Athena X-IFU observations of simulated clusters, and mock WFI images to evaluate the instrument capabilities to extract entropy profiles of distant clusters and groups.
Services currently offered by the infrastructure: The following services will be provided to visitors: i) access to raw data of cosmological hydrodynamical simulations of galaxy clusters; ii) training on the physical processes included in the simulation code (e.g. star formation, stellar evolution, chemical enrichment, feedback from SNe and AGN); iii) training on low-level postprocessing analysis products and software tools: users will become familiar with the procedures to extract intrinsic physical properties of the ICM, to be compared with results from X-ray observations; iv) access to mock X-ray event files generated by synthetic observations of simulated galaxy clusters: such event files can be generated by already developed X-ray simulators which account for the energy-dependent PSF and response functions for different X-ray telescopes.


INAF-Osservatorio Astronomico di Palermo (INAF/OAPa)

The Palermo Astronomical Observatory (OAPa) is one of the research centres of INAF. OAPa hosts the HPC facility SCAN (Computing System for Numerical Astrophysics). The facility consists of three clusters Linux, each based in 64-cores.  Sound experience and the skills necessary to optimize magnetohydrodynamic (MHD) and hydrodynamic (HD) codes for efficient execution on HPC systems, and to develop and apply numerical models to the study of astrophysical plasma, such as that present in the solar and stellar coronae, young stellar objects, and supernova remnants are available. The OAPa group has also a long-term experience in analyzing and interpreting the model results in terms of observable quantities and it has an excellent experience on multi-wavelength data analysis and interpretation.
Services currently offered by the infrastructure: OAPa researchers offer tools developed for the synthesis of emission in different wavelength bands from the models in post-processing. In the framework of this project, two TNA are offered focussing on: 1) accretion/ejection processes in young stellar objects and 2) physics of SNRs and cosmic rays acceleration at shock fronts of SNRs. During the visit, the users will interact with local researchers to develop and test HD/MHD models, and to synthesize emission in different wavelength bands from the model results for a comparison with actual observations. The users will have access to the HPC SCAN facility to setup and test the simulations and to run medium size 2D/3D simulations.


Leiden Observatory, Leiden University

Leiden’s research covers most of astronomy, including high-energy astrophysics. Computational astrophysics is a key research area in which multiple groups at Leiden are active. Recent, cosmological, hydrodynamical simulations projects (co-)led by Leiden include OWLS, Cosmo-OWLS, EAGLE and BAHAMAS. In addition to simulations of representative volumes, Leiden astronomers have developed sets of simulations that zoom in on individual objects, such as the C-EAGLE cluster simulations. New computational techniques and simulations are continuously under development.
Services currently offered by the infrastructure: Leiden Observatory offers access to and help with the analysis of cosmological, hydrodynamical simulations. The suite currently includes simulations from the OWLS, Cosmo-OWLS, EAGLE, BAHAMAS and C-EAGLE projects. The simulations span a wide range of box sizes, resolutions, cosmologies, and galaxy formation scenarios. The EAGLE simulations have already been used in over 250 refereed papers. Software is available for the creation of virtual observations, including both X-ray absorption and X-ray emission. The simulations are particularly well-suited for X-ray studies of the intracluster and intragroup media and the warm-hot intergalactic medium.


University of Ferrara

The University of Ferrara has a long experience in the analysis and broadband modeling of gamma-ray burst prompt and multi-wavelength afterglow emission data, which began BeppoSAX (1996-2002). The local high-energy astrophysics group currently has access to several computing facilities, that have been used to model the fluxes observed at various wavelengths of GRB afterglows.
Services currently offered by the infrastructure:  The infrastructure proposes access to detailed broadband models with sophisticated codes that require high computing facilities. Some results were published in constraining the possible presence of GRB jets in superluminous SNe as well as constraining the properties of the jet associated to GW170817A. The tools can also help visitors model GRB afterglows as well as constrain the presence of relativistic explosions possibly associated to other classes of explosive sources, such as specific classes of SNe.


Physics Department- University of Bath

The University of Bath hosts a number of world experts on the observation and analysis of gamma-ray burst (GRBs) and other high-energy transients, and in relativistic hydrodynamics and simulation-based gamma-ray burst afterglow analysis on the theoretical side. Bath is a stakeholder in LSST, and part of UK-based and international networks on multi-messenger follow-up.
Services currently offered by the infrastructure: The group first conceived of methods to directly map synthetic light curves from high-resolution relativistic jet simulations, and is responsible for open-source analysis tools coupling this approach to Bayesian statistical methods. We offer training in the software package BOXFIT and training in and access to the package scalefit (not yet released publicly). BOXFIT couples jet dynamical simulations to a synchrotron radiation code for rapid computation of spectra and light curves on parallel machines, offering a testing lab for matching jet outflow morphologies and emission approaches to GRB data. Scalefit directly maps synthetic spectra from a sample of jet simulations, and can efficiently perform simulation-based broadband GRB afterglow fits on desktop machines. Simulation-based fitting methods are finding increased use in the community and have been the go-to approach for the initial modeling of the first electro-magnetic counterpart GRB to a gravitational wave trigger.


Universitäts-Sternwarte München, Ludwig-Maximilians Universität München

LMU – Universitäts-Sternwarte München (USM) has a long record for advancing codes for cosmological simulations, constructing and implementing physical processes into such codes. The group realized a suite of large scale cosmological boxes (among them the world largest, cosmological, hydro-dynamical simulation,, which are very well suited for a detailed study of the population of galaxies, small groups of galaxies, and especially galaxy clusters. The group also operates the cosmological web portal where data and mock observations for the simulations can be on the fly generated by the scientific community (
Services currently offered by the infrastructure:
The offered access will allow the scientists to fully exploit the online tools provided by USM. Visitors will be trained how to obtain and process also the raw simulation data which allows them to relate observational features or biases to dynamical or geometrical properties of the underlying objects (like galaxy clusters). They will also be trained how to produce idealized observations of various physical properties which would be accessible across other wavelengths. Overall, this will allow them to better relate their findings to the underlying, physical processes acting to form and evolve the visible, cosmological structures. Examples for such studies from the past ranges from studying how the additional X-ray emission of AGNs influences the expected galaxy cluster count rates in future X-ray surveys with the eROSITA instrument (to be launched in mid 2019) or how the different cosmological objects (like galaxies, clusters and AGNs) can be used to identify voids in future galaxy surveys like the EUCLID mission.


N. Copernicus Astronomical Centre Polish Academy of Science (CAMK PAN)

CAMK PAN is a leading astronomical institute in Poland. The main subjects of research are: stellar astrophysics, binary systems, circumstellar matter, dense matter and neutron stars, black holes, accretion processes, structure and evolution of active galaxies, cosmology, extrasolar planets. There are currently 34 faculty members, 18 post-docs, and 39 PhD students. The computer infrastructure includes cluster with 306 cores.
Services currently offered by the infrastructure: The CAMK PAN team has developed neutron star and accretion disk atmospheres models; they are available on our computational cluster. The visitor will be able to define a grid of models, and to apply them to X-ray satellites. Those models has been recently applied to estimate accuracy of neutron star mass and radius determination with Athena WFI detector. In addition, new ray-tracing code is also ready to use to include relativistic corrections for spectra emitted in the vicinity of black holes and neutron stars. Theory of illumination by hard X-rays including photoionization and coexistence of cold and hot phase in multi-phase medium is continuously developed in CAMK PAN, and can be directly used in any source with available multi-wavelength data.


European Gravitational Observatory

The EGO Consortium was founded by CNRS (France) and INFN (Italy) in 2000, to ensure the long-term scientific exploitation of the VIRGO interferometric antenna for gravitational-wave detection, as well as to foster European collaboration in that scientific field. NIKHEF became a member of the Consortium starting in 2021. EGO is a key player in the commissioning of the VIRGO detector, its operation, maintenance and upgrades. It has created and runs a computing centre for data analysis; promotes R&D activities useful for the detection of gravitational waves; carries out other research of common interest to the members of the Virgo Collaboration in the field of gravitation; promotes cooperation in the field of experimental and theoretical gravitational-wave research in Europe.
Services currently offered by the infrastructure: EGO in collaboration with the Virgo Collaboration, the University of Pisa, the Scuola Normale, the INFN and INGV in Pisa, will offer access to advanced approaches for:  (a) analysis of new sensor networks (robotic grids, fibre networks, seismological and atmospheric detectors) for the of suppression of noise and environmental monitoring of current and next-generation gravitational-wave detectors and interdisciplinary applications (seismology, atmospheric science, ecology); (b) data-quality and detector-characterisation techniques for gravitational-wave detectors; including data-intelligence techniques (e.g. “glitch” characterisation, “tendency” follow-up, semi-automatic detection through correlation of cause and effect) ; (c) development of a low-latency-alert framework for multi-messenger astronomy searches; (d) use of machine and deep learning for gravitational-wave analysis, improving signal-to-noise ratio with innovative solutions for the common analysis of the data of GW detectors and high-energy astrophysics instruments.