The shape of dark matter haloes - II. The GALACTUS H I modelling & fitting tool

S. P. C. Peters, P. C. van der Kruit, R. J. Allen, K. C. Freeman

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)
192 Downloads (Pure)

Abstract

We present a new H I modelling tool called GALACTUS. The program has been designed to perform automated fits of disc-galaxy models to observations. It includes a treatment for the self-absorption of gas. The software has been released into the public domain. We describe the design philosophy and inner workings of the program. After this, we model the face-on galaxy NGC 2403 using both self-absorption and optically thin models, showing that self-absorption occurs even in face-on galaxies. These results are then used to model an edge-on galaxy. It is shown that the maximum surface brightness plateaus seen in Paper I of this series are indeed signs of self-absorption. The apparent H I mass of an edge-on galaxy can be drastically lower compared with that same galaxy seen face-on. The Tully-Fisher relation is found to be relatively free from self-absorption issues.
Original languageEnglish
Pages (from-to)21-31
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Volume464
Issue number1
DOIs
Publication statusPublished - Jan-2017

Keywords

  • galaxies: haloes
  • galaxies: kinematics and dynamics
  • galaxies: photometry
  • galaxies: spiral
  • galaxies: structure
  • DISTANCES
  • EMISSION
  • SPIRAL GALAXY NGC-2403
  • EDGE-ON GALAXIES
  • NEUTRAL HYDROGEN
  • DISK GALAXIES
  • APERTURE-SYNTHESIS
  • ROTATION CURVES
  • GAS
  • OPTIMIZATION

Cite this