Recognizing the fingerprints of the Galactic bar: a quantitative approach to comparing model (l,v) distributions to observation

Abstract

We present a new method for fitting simple hydrodynamical models to the (l,v) distribution of atomic and molecular gas observed in the Milky Way. The method works by matching features found in models and observations. It is based on the assumption that the large-scale features seen in (l,v) plots, such as ridgelines and the terminal velocity curve, are influenced primarily by the underlying large-scale Galactic potential and are only weakly dependent on local ISM heating and cooling processes. In our scheme one first identifies by hand the features in the observations: this only has to be done once. We describe a procedure for automatically extracting similar features from simple hydrodynamical models and quantifying the "distance" between each model's features and the observations. Application to models of the Galactic Bar region (|l|<30deg) shows that our feature-fitting method performs better than χ^2 or envelope distances at identifying the correct underlying galaxy model.

Accepted for publication in MNRAS

References in corpus (5)

• Gas flow models in the Milky Way embedded bars
• Cloud and Star Formation in Disk Galaxy Models with Feedback
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Three-dimensional extinction mapping using Gaussian random fields
• Multiplicity of nuclear dust lanes and dust lane shocks in the Milky Way bar

Cited by in corpus (10)

• Distribution and kinematics of atomic and molecular gas inside the Solar circle
• The morphology of the Milky Way - II. Reconstructing CO maps from disc galaxies with live stellar distributions
• The volumetric star formation law in the Milky Way
• The Milky Way's bar structural properties from gravitational waves
• Young stars as tracers of a barred-spiral Milky Way
• HyGAL: Characterizing the Galactic ISM with observations of hydrides and other small molecules -- I. Survey description and a first look toward W3(OH), W3 IRS5 and NGC 7538 IRS1
• Extending the view of ArH+ chemistry in diffuse clouds
• Revealing Gas Inflows towards the Galactic Central Molecular Zone
• HyGAL: Characterizing the Galactic ISM with observations of hydrides and other small molecules II. The absorption line survey with the IRAM 30 m telescope
• One-kpc Expanding Cylinder of HI-Gas around the Galactic Center