Co-evolution of Dust and Chemistry in Galaxy Simulations with a Resolved Interstellar Medium

Hu, Chia-Yu; Sternberg, A.; Dishoeck, E. F. van

doi:10.48550/arxiv.2301.05247

Cited by 3 publications

(1 citation statement)

References 66 publications

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“…We also show the possible observational bands for future COMAP phases considered in simulated scenarios in this work, as well as the specific target and interloper components (solid and dotted boxes respectively) for reionisation-epoch CO LIM observations. molecular gas and dust in dense environments (cf., e.g., [31,32]), CO measurements at these high redshifts will provide important insights into cooling and heating mechanisms governing star formation at the very inception of the star-forming cosmic web. The addition of instrumentation outside the 26-34 GHz COMAP Pathfinder frequency range is thus transformative, not incremental.…”

Section: Jcap12(2023)024mentioning

confidence: 99%

Constraining the halo-ISM connection through multi-transition carbon monoxide line-intensity mapping

Chung

2023

J. Cosmol. Astropart. Phys.

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Line-intensity mapping (LIM) surveys will characterise the cosmological large-scale structure of emissivity in a range of atomic and molecular spectral lines, but existing literature rarely considers whether these surveys can recover excitation properties of the tracer gas species, such as the carbon monoxide (CO) molecule. Combining basic empirical and physical assumptions with the off-the-shelf Radex radiative transfer code or a Gaussian process emulator of Radex outputs, we devise a basic dark matter halo model for CO emission by tying bulk CO properties to halo properties, exposing physical variables governing CO excitation as free parameters. The CO Mapping Array Project (COMAP) is working towards a multi-band survey programme to observe both CO(1–0) and CO(2–1) at z ∼ 7. We show that this programme, as well as a further `Triple Deluxe' extension to higher frequencies covering CO(3–2), is fundamentally capable of successfully recovering the connection between halo mass and CO abundances, and constraining the molecular gas kinetic temperature and density within the star-forming interstellar medium in ways that single-transition CO LIM cannot. Given a fiducial thermal pressure of ∼ 104 K cm-3 for molecular gas in halos of ∼ 1010 M ⊙, simulated multi-band COMAP surveys successfully recover the thermal pressure within 68% interval half-widths of 0.5–0.6 dex. Construction of multi-frequency LIM instrumentation to access multiple CO transitions is crucial in harnessing this capability, as part of a cosmic statistical probe of gas metallicity, dust chemistry, and other physical parameters in star-forming regions of the first galaxies and proto-galaxies out of reionisation.

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Section: Jcap12(2023)024mentioning

confidence: 99%

Constraining the halo-ISM connection through multi-transition carbon monoxide line-intensity mapping

Chung

2023

J. Cosmol. Astropart. Phys.

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Effects of dust grain size distribution on the abundances of CO and H2 in galaxy evolution

Hirashita

2023

Monthly Notices of the Royal Astronomical Society

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We model the effect of grain size distribution in a galaxy on the evolution of CO and H2 abundances. The formation and dissociation of CO and H2 in typical dense clouds are modelled in a manner consistent with the grain size distribution. The evolution of grain size distribution is calculated based on our previous model, which treats the galaxy as a one-zone object but includes various dust processing mechanisms in the interstellar medium (ISM). We find that typical dense clouds become fully molecular (H2) when the dust surface area increases by shattering while an increase of dust abundance by dust growth in the ISM is necessary for a significant rise of the CO abundance. Accordingly, the metallicity dependence of the CO-to-H2 conversion factor, XCO, is predominantly driven by dust growth. We also examine the effect of grain size distribution in the galaxy by changing the dense gas fraction, which controls the balance between coagulation and shattering, clarifying that the difference in the grain size distribution significantly affects XCO even if the dust-to-gas ratio is the same. The star formation time-scale, which controls the speed of metal enrichment also affects the metallicity at which the CO abundance rapidly increases (or XCO drops). We also propose dust-based formulae for XCO, which need further tests for establishing their usefulness.

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The minimum mass for star formation by dynamical fragmentation: dependence on epoch, dust abundance, and environment

Whitworth,

Priestley,

Wünsch

et al. 2024

Monthly Notices of the Royal Astronomical Society

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We estimate the minimum mass for a star formed by dynamical collapse and fragmentation, as a function of epoch, dust abundance, and environment. Epoch is parametrised by redshift, zred, through the variation in the temperature of the cosmic microwave background. Dust abundance is parametrised by the mass-fraction in dust, ZD, with the additional simplifying assumption that the intrinsic properties of dust do not change with ZD, only the amount of dust. Environment is parametrised by the energy-density of the ambient suprathermal radiation fields through a dilution factor ω⋆ (applied to a blackbody radiation field at T⋆ = 104 K). The critical condition is that a spherical proto-fragment should be able to cool, and therefore contract, fast enough to detach from neighbouring proto-fragments. The minimum mass increases with increasing redshift, increasing dust abundance, and increasing suprathermal background. Values in the range from MMIN ∼ 0.002 M⊙ to MMIN ∼ 0.2 M⊙ are obtained at the extremes of the parameter ranges we have considered (0 ≤ zred ≤ 8, 0.00016 < ZD < 0.04 and 10−15 ≤ ω⋆ ≤ 10−8). Our results agree quite well with the predictions of detailed numerical simulations invoking similar redshifts and dust abundances, but our estimates are somewhat lower; we attribute this difference to resolution issues and the small-number statistics from the simulations. The increased minimum masses predicted at high redshift and/or high suprathermal background result in significantly bottom-light IMFs, and therefore low mass-to-light ratios, provided that the dust abundance is not too low. The changes due to high suprathermal background may be particularly important for star formation in galactic nuclei and at high redshift.

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Co-evolution of Dust and Chemistry in Galaxy Simulations with a Resolved Interstellar Medium

Cited by 3 publications

References 66 publications

Constraining the halo-ISM connection through multi-transition carbon monoxide line-intensity mapping

Constraining the halo-ISM connection through multi-transition carbon monoxide line-intensity mapping

Effects of dust grain size distribution on the abundances of CO and H2 in galaxy evolution

The minimum mass for star formation by dynamical fragmentation: dependence on epoch, dust abundance, and environment

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