Resolving the Dust-to-Metals Ratio and CO-to-H${}_2$ Conversion Factor in the Nearby Universe

Abstract

We investigate the relationship between the dust-to-metals ratio (D/M) and the local interstellar medium environment at ~2 kpc resolution in five nearby galaxies: IC342, M31, M33, M101, and NGC628. A modified blackbody model with a broken power-law emissivity is used to model the dust emission from 100 to 500 um observed by Herschel. We utilize the metallicity gradient derived from auroral line measurements in HII regions whenever possible. Both archival and new CO rotational line and HI 21 cm maps are adopted to calculate gas surface density, including new wide field CO and HI maps for IC342 from IRAM and the VLA, respectively. We experiment with several prescriptions of CO-to-H${}_2$ conversion factor, and compare the resulting D/M-metallicity and D/M-density correlations, both of which are expected to be non-negative from depletion studies. The D/M is sensitive to the choice of the conversion factor. The conversion factor prescriptions based on metallicity only yield too much molecular gas in the center of IC342 to obtain the expected correlations. Among the prescriptions tested, the one that yields the expected correlations depends on both metallicity and surface density. The 1-$\sigma$ range of the derived D/M spans 0.40-0.58. Compared to chemical evolution models, our measurements suggest that the dust growth time scale is much shorter than the dust destruction time scale. The measured D/M is consistent with D/M in galaxy-integrated studies derived from infrared dust emission. Meanwhile, the measured D/M is systematically higher than the D/M derived from absorption, which likely indicates a systematic offset between the two methods.

22 pages, 8 figures, 4 tables; accepted by ApJ

References in corpus (25)

• The NumPy array: a structure for efficient numerical computation
• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• HyperLEDA. III. The catalogue of extragalactic distances
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• Evolution of interstellar dust and stardust in the solar neighbourhood
• The Cosmic Baryon and Metal Cycles
• A z=0 Multi-wavelength Galaxy Synthesis I: A WISE and GALEX Atlas of Local Galaxies
• CHAOS I: Direct Chemical Abundances for HII Regions in NGC 628
• Dust and Gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. I. Dust Properties and Insights into the Origin of the Submm Excess Emission
• Mapping metallicity variations across nearby galaxy disks
• PHANGS CO kinematics: disk orientations and rotation curves at 150 pc resolution
• A Wide-field High Resolution HI Mosaic of Messier 31: I. Opaque Atomic Gas and Star Formation Rate Density
• Modelling Dust Evolution in Galaxies with a Multiphase, Inhomogeneous ISM
• Dust and Gas in the Magellanic Clouds from the HERITAGE Herschel Key Project. II. Gas-to-Dust Ratio Variations across ISM Phases
• The dust budget crisis in high-redshift submillimetre galaxies
• Dust origin in late-type dwarf galaxies: ISM growth vs. type II supernovae
• Physical Properties of Molecular Clouds at 2 parsec Resolution in the Low-Metallicity Dwarf Galaxy NGC 6822 and the Milky Way
• Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: The KINGFISH Sample
• Full-disc ${}^{13}$CO(1-0) mapping across nearby galaxies of the EMPIRE survey and the CO-to-H${}_2$ conversion factor
• Dust-depletion sequences in damped Lyman-α absorbers: a unified picture from low-metallicity systems to the Galaxy
• Dust scaling relations in a cosmological simulation
• Infrared Tip of the Red Giant Branch and Distances to the Maffei/IC 342 Group
• Thermal and nonthermal dust sputtering in hydrodynamical simulations of the multiphase interstellar medium
• METAL: The Metal Evolution, Transport, and Abundance in the Large Magellanic Cloud Hubble program. I. Overview and Initial Results
• Metal Abundances and Depletions in the Neutral Interstellar Medium of Galaxies: the Local Volume as a Laboratory

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• METAL: The Metal Evolution, Transport, and Abundance in the Large Magellanic Cloud Hubble program. III. Interstellar Depletions, Dust-to-Metal, and Dust-to-Gas Ratios Versus Metallicity
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• The Galactic Dust-Up: Modeling Dust Evolution in FIRE
• Star Formation and Molecular Gas Diagnostics with Mid- and Far-Infrared Emission
• Euclid: Early Release Observations -- Deep anatomy of nearby galaxies
• Dust temperature uncertainties hamper the inference of dust and molecular gas masses from the dust continuum emission of quiescent high-redshift galaxies
• A Dusty Locale: Evolution of Galactic Dust Populations from Milky Way to Dwarf-Mass Galaxies
• Benchmarking Dust Emission Models in M101
• Dynamical effects of the radiative stellar feedback on the H I-to-H2 transition
• The effects of local stellar radiation and dust depletion on non-equilibrium interstellar chemistry
• The Karl G. Jansky Very Large Array Local Group L-band Survey (LGLBS)
• Dust emissivity in resolved spiral galaxies
• Kpc-scale properties of dust temperature in terms of dust mass and star formation activity
• Effects of dust sources on dust attenuation properties in IllustrisTNG galaxies at $z\sim 7$
• The intrinsic reddening of the Magellanic Clouds as traced by background galaxies -- III. The Large Magellanic Cloud
• Effects of dust grain size distribution on the abundances of CO and H${}_2$ in galaxy evolution
• A sensitive, high-resolution, wide-field IRAM NOEMA CO(1-0) survey of the very nearby spiral galaxy IC 342
• CO-to-H${}_2$ conversion factor and grain size distribution through the analysis of ${\alpha }_{\mathrm{CO}}$-$q_{\mathrm{PAH}}$ relation
• Ashes of FIRE: Modeling Dust Grain Size Evolution in the Local Group with FIRE
• Revealing the Connection Between the Filamentary Hierarchy and Star Cluster Formation in a Simulated NGC 628 Galaxy