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.

arXiv commentMNRAS accepted; 11 pages, 12 figures

References in corpus (21)

• The VLA Galactic Plane Survey
• Modelling discontinuities and Kelvin-Helmholtz instabilities in SPH
• The Southern Galactic Plane Survey: HI Observations and Analysis
• GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release
• Molecular Cloud Formation Behind Shock Waves
• HI Narrow Line Absorption in Dark Clouds
• GMC formation by agglomeration and self gravity
• The Disruption and Fueling of M33
• The ISM in spiral galaxies: can cooling in spiral shocks produce molecular clouds?
• Magnetically Dominated Strands of Cold Hydrogen in the Riegel-Crutcher Cloud
• Effects of Magnetic Field Strength and Orientation on Molecular Cloud Formation
• A Self-Absorption Census of Cold HI Clouds in the Canadian Galactic Plane Survey
• The Transition from Atomic to Molecular Hydrogen in Interstellar Clouds: 21cm Signature of the Evolution of Cold Atomic Hydrogen in Dense Clouds
• Molecular gas, CO, and star formation in galaxies: emergent empirical relations, feedback, and the evolution of very gas-rich systems
• Magnetic fields and the dynamics of spiral galaxies
• Spiral shocks and the formation of molecular clouds in a two phase medium
• Low-Velocity Halo Clouds
• "Missing Link" Clouds in the Southern Galactic Plane Survey
• A peculiar HI cloud near the distant globular cluster Pal 4
• The Milky Way's dark matter halo appears to be lopsided
• CO in HI Self-Absorbed Clouds in Perseus

Cited by in corpus (12)

• Dawes Review 4: Spiral Structures in Disc Galaxies
• The properties of the ISM in disc galaxies with stellar feedback
• What can simulated molecular clouds tell us about real molecular clouds?
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Synthetic observations of star formation and the interstellar medium
• 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 structure of HI in galactic disks: Simulations vs observations
• 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
• Adaptive image ray-tracing for astrophysical simulations