Computational astrophysics refers to the methods and computing tools developed and used in

astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the h ...

research. Like

computational chemistry Computational chemistry is a branch of chemistry that uses computer simulation to assist in solving chemical problems. It uses methods of theoretical chemistry, incorporated into computer programs, to calculate the structures and properties of mo ...

computational physics Computational physics is the study and implementation of numerical analysis to solve problems in physics for which a quantitative theory already exists. Historically, computational physics was the first application of modern computers in science, ...

, it is both a specific branch of

theoretical astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the hea ...

and an interdisciplinary field relying on

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

, and wider

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which ...

. Computational astrophysics is most often studied through an applied mathematics or astrophysics programme at PhD level. Well-established areas of astrophysics employing computational methods include

magnetohydrodynamics Magnetohydrodynamics (MHD; also called magneto-fluid dynamics or hydromagnetics) is the study of the magnetic properties and behaviour of electrically conducting fluids. Examples of such magnetofluids include plasmas, liquid metals, ...

, astrophysical radiative transfer, stellar and

galactic Galactic is an American jam band from New Orleans, Louisiana. Origins and background Formed in 1994 as an octet (under the name Galactic Prophylactic) and including singer Chris Lane and guitarist Rob Gowen, the group was soon pared down to a ...

dynamics, and astrophysical

fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) a ...

. A recently developed field with interesting results is

numerical relativity Numerical relativity is one of the branches of general relativity that uses numerical methods and algorithms to solve and analyze problems. To this end, supercomputers are often employed to study black holes, gravitational waves, neutron stars a ...

Research

Many astrophysicists use computers in their work, and a growing number of astrophysics departments now have research groups specially devoted to computational astrophysics. Important research initiatives include the

US Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States. ...

(DoE) SciDAC collaboration for astrophysics"SciDAC Astrophysics Consortium"
Retrieved 8 March 2012. and the now defunct European AstroSim collaboration. A notable active project is the international Virgo Consortium, which focuses on cosmology. In August 2015 during the general assembly of the International Astronomical Union a new
commission C.B1 on Computational Astrophysics
was inaugurated, therewith recognizing the importance of astronomical discovery by computing. Important techniques of computational astrophysics include particle-in-cell (PIC) and the closely related particle-mesh (PM),

N-body simulations In physics and astronomy, an ''N''-body simulation is a simulation of a dynamical system of particles, usually under the influence of physical forces, such as gravity (see ''n''-body problem for other applications). ''N''-body simulations ...

, Monte Carlo methods, as well as grid-free (with

smoothed particle hydrodynamics Smoothed-particle hydrodynamics (SPH) is a computational method used for simulating the mechanics of continuum media, such as solid mechanics and fluid flows. It was developed by Gingold and Monaghan and Lucy in 1977, initially for astrophysi ...

(SPH) being an important example) and grid-based methods for fluids. In addition, methods from

numerical analysis Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods ...

for solving ODEs and PDEs are also used.

Simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model, models; the model represents the key characteristics or behaviors of the selected system or proc ...

of astrophysical flows is of particular importance as many objects and processes of astronomical interest such as stars and nebulae involve gases. Fluid computer models are often coupled with radiative transfer, (Newtonian) gravity, nuclear physics and (general) relativity to study highly energetic phenomena such as supernovae,

relativistic jets An astrophysical jet is an astronomical phenomenon where outflows of ionised matter are emitted as an extended beam along the axis of rotation. When this greatly accelerated matter in the beam approaches the speed of light, astrophysical jets bec ...

active galaxies An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not pro ...

and

gamma-ray bursts In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten millis ...

and are also used to model

stellar structure Stellar structure models describe the internal structure of a star in detail and make predictions about the luminosity, the color and the future evolution of the star. Different classes and ages of stars have different internal structures, reflec ...

, planetary formation, evolution of stars and of galaxies, and exotic objects such as neutron stars,

pulsars A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward E ...

magnetars A magnetar is a type of neutron star with an extremely powerful magnetic field (∼109 to 1011 T, ∼1013 to 1015 G). The magnetic-field decay powers the emission of high-energy electromagnetic radiation, particularly X-rays and gamma rays.War ...

and black holes.

Computer simulation Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...

s are often the only means to study stellar collisions,

galaxy merger Galaxy mergers can occur when two (or more) galaxies collide. They are the most violent type of galaxy interaction. The gravitational interactions between galaxies and the friction between the gas and dust have major effects on the galaxies ...

s, as well as

and black hole interactions. In recent years the field has made increasing use of

parallel Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster o ...

and high performance computers.

Tools

Computational astrophysics as a field makes extensive use of software and hardware technologies. These systems are often highly specialized and made by dedicated professionals, and so generally find limited popularity in the wider (computational) physics community.

Hardware

Like other similar fields, computational astrophysics makes extensive use of supercomputers and computer clusters . Even on the scale of a normal desktop it is possible to accelerate the hardware. Perhaps the most notable such

computer architecture In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the ...

built specially for astrophysics is the GRAPE (gravity pipe) in Japan. As of 2010, the biggest N-body simulations, such as DEGIMA, do

general-purpose computing on graphics processing units General-purpose computing on graphics processing units (GPGPU, or less often GPGP) is the use of a graphics processing unit (GPU), which typically handles computation only for computer graphics, to perform computation in applications traditiona ...

Software

Many codes and software packages, exist along with various researchers and consortia maintaining them. Most codes tend to be n-body packages or fluid solvers of some sort. Examples of n-body codes include ChaNGa, MODEST, nbodylab.org and Starlab. For hydrodynamics there is usually a coupling between codes, as the motion of the fluids usually has some other effect (such as gravity, or radiation) in astrophysical situations. For example, for SPH/N-body there is

GADGET A gadget is a mechanical device or any ingenious article. Gadgets are sometimes referred to as ''gizmos''. History The etymology of the word is disputed. The word first appears as reference to an 18th-century tool in glassmaking that was develop ...

and SWIFT; for grid-based/N-body RAMSES, ENZO, FLASH, and ART. AMUS

takes a different approach (called Noah's ArkPortegies Zwart et al., "A multiphysics and multiscale software environment for modeling astrophysical systems", NewA, 14, 369, (2009)) than the other packages by providing an interface structure to a large number of publicly available astronomical codes for addressing stellar dynamics, stellar evolution, hydrodynamics and radiative transport.

References

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Research

Tools

Hardware

Software

See also

References

Further reading