M51 revisited: A genetic algorithm approach of its interaction history

  title={M51 revisited: A genetic algorithm approach of its interaction history},
  author={Christian Theis and Ch. Spinneker},
  journal={Astrophysics and Space Science},
Detailed models of observed interacting galaxies suffer from the extended parameter space. Here, we present results from our code MINGA which couples an evolutionary optimization strategy (a genetic algorithm) with a fast N-body method. MINGA allows for an automatic search of the optimal region(s) in parameter space within a few hours to a few days of CPU time on a modern PC by investigating of the order of 105 models. We demonstrate its applicability by modelling the HI intensity and velocity… 
Modeling the initial conditions of interacting galaxy pairs using Identikit
We develop and test an automated technique to model the dynamics of interacting galaxy pairs. We use Identikit (Barnes & Hibbard 2009, Barnes 2011) as a tool for modeling and matching the morphology
The evolution of interacting spiral galaxy NGC 5194
NGC 5194 (M51a) is a grand-design spiral galaxy and undergoing interactions with its companion. Here, we focus on investigating main properties of its star formation history (SFH) by constructing a
By combining test-particle and self-consistent techniques, a method to rapidly explore the parameter space of galactic encounters is developed and it is shown that it is usually possible to reproduce the morphology and kinematics of these encounters and that a good match strongly constrains the encounter parameters.
Evolutionary Computation in Astronomy and Astrophysics: A Review
Some promising applications in Evolutionary Computation are discussed and a general description of EC is included to provide a global perspective to the reader and some guidelines of application of EC techniques for future research are given.
Simulations of the star-forming molecular gas in an interacting M51-like galaxy
We present here the first of a series of papers aimed at better understanding the evolution and properties of giant molecular clouds (GMCs) in a galactic context. We perform high-resolution,
Measuring Dark Matter by Modeling Interacting Galaxies
The dark matter content of galaxies is usually determined from galaxies in dynamical equilibrium, mainly from rotationally supported galactic components. Such determinations restrict measurements to
Modelling the cosmic ray electron propagation in M 51
Cosmic ray electrons (CREs) are a crucial part of the ISM and are observed via synchrotron emission. While much modelling has been carried out on the CRE distribution and propagation of the Milky
The Interstellar Line of Sight to the Interacting Galaxy NGC 5195
We present moderately-high resolution echelle observations of the nucleus of NGC 5195, the line of sight to which samples intervening interstellar material associated with the outer spiral arm of
High-resolution, 3D radiative transfer modelling
Investigating the dust heating mechanisms in galaxies provides a deeper understanding of how the internal energy balance drives their evolution. Over the last decade, radiative transfer simulations
HI in Arp72 and similarities with M51-type systems
We present neutral hydrogen (H{\sc i}) observations with the Giant Metrewave Radio Telescope ({\it GMRT}) of the interacting galaxies NGC5996 and NGC5994, which make up the Arp72 system. Arp72 is an


Determination of the orbital parameters of the M 51 system using a genetic algorithm
Using an efficient method based on genetic algorithms, we have searched for an optimum set of parameters for the interaction between NGC 5194 (M 51) and NGC 5195. The preferred model is one where the
Multi-method-modeling of interacting galaxies I. A unique scenario for NGC 4449?
NGC 4449 is an active star-forming dwarf ga la xy of Magellanic type. From radio observations, van Woerden et al. ([CITE]) found an extended HI-halo around NGC 4449 which is at least a factor of 10
Determination of orbital parameters of interacting galaxies using a genetic algorithm - Description of the method and application to artificial data
A method for determining the orbital parameters of interacting pairs of galaxies is presented and evaluated using artificial data. The method consists of a genetic algorithm which can search
N-body model for M51 — I. Multiple encounter versus single passage?
A numerical survey of the encounter history of the interacting grand-design system M51 (NGC 5194/5195) is performed with a 3D multiple spherical polar grid code, where both components of the pair are
This paper presents new VLA observations in the 21 cm H I line of the Sc spiral galaxy M51 (NGC 5194) at resolutions ranging from 5 arcsec to 34 arcsec. The H I in the inner regions follows the
Galactic Bridges and Tails
This paper argues that the bridges and tails seen in some multiple galaxies are just tidal relics of close encounters. These consequences of the brief but violent tidal forces are here studied in a