A Synthetic 21-cm Galactic Plane Survey of an SPH Galaxy Simulation

Abstract

We have created synthetic neutral hydrogen (HI) Galactic Plane Survey data cubes covering 90 degrees < l < 180 degrees, using a model spiral galaxy from SPH simulations and the radiative transfer code TORUS. The density, temperature and other physical parameters are fed from the SPH simulation into TORUS, where the HI emissivity and opacity are calculated before the 21-cm line emission profile is determined. Our main focus is the observation of Outer Galaxy `Perseus Arm' HI, with a view to tracing atomic gas as it encounters shock motions as it enters a spiral arm interface, an early step in the formation of molecular clouds. The observation of HI self-absorption features at these shock sites (in both real observations and our synthetic data) allows us to investigate further the connection between cold atomic gas and the onset of molecular cloud formation.

MNRAS accepted; 11 pages, 12 figures

References in corpus (8)

• The VLA Galactic Plane Survey
• Modelling discontinuities and Kelvin-Helmholtz instabilities in SPH
• GMC formation by agglomeration and self gravity
• The ISM in spiral galaxies: can cooling in spiral shocks produce molecular clouds?
• Magnetically Dominated Strands of Cold Hydrogen in the Riegel-Crutcher Cloud
• The Transition from Atomic to Molecular Hydrogen in Interstellar Clouds: 21cm Signature of the Evolution of Cold Atomic Hydrogen in Dense Clouds
• Magnetic fields and the dynamics of spiral galaxies
• A peculiar HI cloud near the distant globular cluster Pal 4

Cited by in corpus (7)

• Dawes Review 4: Spiral Structures in Disc Galaxies
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Synthetic CO, H2 and HI surveys of the Galactic 2nd Quadrant, and the properties of molecular gas
• Recovering interstellar gas properties with HI spectral lines: A comparison between synthetic spectra and 21-SPONGE
• On the accuracy of HI observations in molecular clouds -- More cold HI than thought?
• The Shape of Dark Matter Haloes III. Kinematics and Structure of the HI disc
• Drivers of asymmetry in synthetic H I emission-line profiles of galaxies in the EAGLE simulation