Synthetic CO, H2 and HI surveys of the Galactic 2nd Quadrant, and the properties of molecular gas

Abstract

We present CO, H2, HI and HISA distributions from a set of simulations of grand design spirals including stellar feedback, self-gravity, heating and cooling. We replicate the emission of the 2nd Galactic Quadrant by placing the observer inside the modelled galaxies and post process the simulations using a radiative transfer code, so as to create synthetic observations. We compare the synthetic datacubes to observations of the 2nd Quadrant of the Milky Way to test the ability of the current models to reproduce the basic chemistry of the Galactic ISM, as well as to test how sensitive such galaxy models are to different recipes of chemistry and/or feedback. We find that models which include feedback and self-gravity can reproduce the production of CO with respect to H2 as observed in our Galaxy, as well as the distribution of the material perpendicular to the Galactic plane. While changes in the chemistry/feedback recipes do not have a huge impact on the statistical properties of the chemistry in the simulated galaxies, we find that the inclusion of both feedback and self-gravity are crucial ingredients, as our test without feedback failed to reproduce all of the observables. Finally, even though the transition from H2 to CO seems to be robust, we find that all models seem to underproduce molecular gas, and have a lower molecular to atomic gas fraction than is observed. Nevertheless, our fiducial model with feedback and self-gravity has shown to be robust in reproducing the statistical properties of the basic molecular gas components of the ISM in our Galaxy.

arXiv commentAccepted for publication in MNRAS

References in corpus (31)

• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Planck 2013 results. I. Overview of products and scientific results
• The Neutral Atomic Phases of the ISM in the Galaxy
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• SPLASH: An interactive visualisation tool for Smoothed Particle Hydrodynamics simulations
• The VLA Galactic Plane Survey
• GASS: The Parkes Galactic All-Sky Survey. I. Survey Description, Goals, and Initial Data Release
• The Southern Galactic Plane Survey: HI Observations and Analysis
• A Herschel [CII] Galactic plane survey I: the global distribution of ISM gas components
• Simulating the formation of molecular clouds. I. Slow formation by gravitational collapse from static initial conditions
• Ultraviolet Survey of CO and H_2 in Diffuse Molecular Clouds: The Reflection of Two Photochemistry Regimes in Abundance Relationships
• The GALFA-HI Survey: Data Release 1
• CO-dark gas and molecular filaments in Milky Way type galaxies
• Modeling CO Emission: I. CO as a Column Density Tracer and the X-Factor in Molecular Clouds
• The Exciting Lives of Giant Molecular Clouds
• The properties of the ISM in disc galaxies with stellar feedback
• The Atomic-to-Molecular Transition in Galaxies. III. A New Method for Determining the Molecular Content of Primordial and Dusty Clouds
• Direct Measurement of the Ratio of Carbon Monoxide to Molecular Hydrogen in the Diffuse Interstellar Medium
• Modeling CO Emission: II. The Physical Characteristics that Determine the X factor in Galactic Molecular Clouds
• The formation of molecular clouds in spiral galaxies
• The Effelsberg-Bonn HI Survey (EBHIS)
• The ISM in spiral galaxies: can cooling in spiral shocks produce molecular clouds?
• A Self-Absorption Census of Cold HI Clouds in the Canadian Galactic Plane Survey
• The morphology of the Milky Way - I. Reconstructing CO maps from simulations in fixed potentials
• Three Dimensional Hydrodynamic Simulations of Multiphase Galactic Disks with Star Formation Feedback: II. Synthetic HI 21 cm Line Observations
• "Missing Link" Clouds in the Southern Galactic Plane Survey
• Three-dimensional molecular line transfer: A simulated star-forming region
• Modeling the physical and excitation conditions of the molecular envelope of NGC 7027
• CO in HI Self-Absorbed Clouds in Perseus
• A Synthetic 21-cm Galactic Plane Survey of an SPH Galaxy Simulation
• The structure of HI in galactic disks: Simulations vs observations

Cited by in corpus (26)

• The origin of fast molecular outflows in quasars: molecule formation in AGN-driven galactic winds
• SILCC-Zoom: The dynamical and chemical evolution of molecular clouds
• CHIMPS: the ${}^{13}$CO/C${}^{18}$O (J=3-2) Heterodyne Inner Milky Way Plane Survey
• The environmental dependence of the X_CO conversion factor
• The integrated properties of the molecular clouds from the JCMT CO(3-2) High Resolution Survey
• SILCC-Zoom: H${}_2$ and CO-dark gas in molecular clouds -- The impact of feedback and magnetic fields
• What can simulated molecular clouds tell us about real molecular clouds?
• Structure distribution and turbulence in self-consistently supernova-driven ISM of multiphase magnetized galactic discs
• The X_CO conversion factor from galactic multiphase ISM simulations
• The SEDIGISM survey: Molecular clouds in the inner Galaxy
• Metallicity dependence of the H/H${}_2$ and C${}^{+}$/C/CO distributions in a resolved self-regulating interstellar medium
• The effects of metallicity, UV radiation and non-equilibrium chemistry in high-resolution simulations of galaxies
• The Physical Drivers and Observational Tracers of CO-to-H2 Conversion Factor Variations in Nearby Barred Galaxy Centers
• Different studies of the global pitch angle of the Milky Way's spiral arms
• Dependence of $X_{\mathrm{CO}}$ on metallicity, intensity, and spatial scale in a self-regulated interstellar medium
• Simulations of the flocculent spiral M33: what drives the spiral structure?
• Synthetic observations of star formation and the interstellar medium
• PHANGS-JWST First Results: The Dust Filament Network of NGC 628 and its Relation to Star Formation Activity
• Recovering interstellar gas properties with HI spectral lines: A comparison between synthetic spectra and 21-SPONGE
• Populating H${}_2$ and CO in galaxy simulation with dust evolution
• The Molecular Structures of Local Arm and Perseus Arm in the Galactic Region of l=[139.75,149.75]${}^{\circ }$, b=[-5.25,5.25]${}^{\circ }$
• An Outer Arm in the Second Galactic Quadrant: Structure
• Comparing the Properties of GMCs in M33 from Simulations and Observations
• Reproducing the CO-to-H${}_2$ conversion factor in cosmological simulations of Milky Way-mass galaxies
• The role of previous generations of stars in triggering star formation and driving gas dynamics
• A SOFIA Survey of [CII] in the galaxy M51 II. [CII] and CO kinematics across spiral arms