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We present the spatially resolved relationship between the dust-to-gas mass ratio (DGR) and gas-phase metallicity (⁠|$Z_{\rm gas}$| or 12 + log(O/H)) (i.e. DGR– |$Z_{\rm gas}$| relation) of 11 nearby galaxies with a large-metallicity range (1.5 dex of 12 + log(O/H)) at (sub-)kpc scales. We used the large field-of-view (⁠|$\gtrsim$| 3 arcmin) optical pseudo-Integral Field Spectroscopy data taken by the TYPHOON/Progressive Integral Step Method survey, covering the optical size of galaxies, combining them with multiwavelength data [far-ultrviolet (UV) to far-infrared (IR), CO, and H  i 21 cm radio]. A large scatter of DGR in the intermediate-metallicity galaxies (8.0 |$\lt $| 12 + log(O/H) |$\lt $| 8.3) is found, which is in line with dust evolution models, where grain growth begins to dominate the mechanism of dust mass accumulation. In the lowest metallicity galaxy of our sample, Sextans A (12 + log(O/H) |$\lt $| 7.6), the star-forming regions have significantly higher DGR values (by 0.5–2 dex) than the global estimates from literature at the same metallicity, but aligns with the DGR values from metal depletion method from damped Lyman alpha systems and high hydrogen gas density regions of Sextans A. Using dust evolution models with a Bayesian Monte Carlo Markov Chain approach suggests: (1) a high supernova dust yield and (2) a negligible amount of photofragmentation by UV radiation, although we note that our sample in the low-metallicity regime is limited to Sextans A. On the other hand, it is also possible that while metallicity influences DGR, gas density also plays a role, indicating an early onset of dust grain growth in the dust mass build-up process despite its low metallicity. [ABSTRACT FROM AUTHOR]

Most star formation in the local Universe occurs in spiral galaxies, but their origin remains an unanswered question. Various theories have been proposed to explain the development of spiral arms, each predicting different spatial distributions of the interstellar medium. This study maps the star formation rate (SFR) and gas-phase metallicity of nine spiral galaxies with the TYPHOON survey to test two dominating theories: density wave theory and dynamic spiral theory. We discuss the environmental effects on our galaxies, considering reported environments and merging events. Taking advantage of the large field of view covering the entire optical disc, we quantify the fluctuation of SFR and metallicity relative to the azimuthal distance from the spiral arms. We find higher SFR and metallicity in the trailing edge of NGC 1365 (by 0.117 and 0.068 dex, respectively) and NGC 1566 (by 0.119 and 0.037 dex, respectively), which is in line with density wave theory. NGC 2442 shows a different result with higher metallicity (0.093 dex) in the leading edge, possibly attributed to an ongoing merging. The other six spiral galaxies show no statistically significant offset in SFR or metallicity, consistent with dynamic spiral theory. We also compare the behaviour of metallicity inside and outside the corotation radius (CR) of NGC 1365 and NGC 1566. We find comparable metallicity fluctuations near and beyond the CR of NGC 1365, indicating gravitational perturbation. NGC 1566 shows the greatest fluctuation near the CR, in line with the analytic spiral arms. Our work highlights that a combination of mechanisms explains the origin of spiral features in the local Universe. [ABSTRACT FROM AUTHOR]

We measure the ionized gas velocity dispersions of star-forming galaxies in the MAGPI survey (⁠|$z\sim 0.3$|⁠) and compare them with galaxies in the SAMI (⁠|$z\sim 0.05$|⁠) and KROSS (⁠|$z\sim 1$|⁠) surveys to investigate how the ionized gas velocity dispersion evolves. For the first time, we use a consistent method that forward models galaxy kinematics from |$z=0$| to |$z=1$|⁠. This method accounts for spatial substructure in emission line flux and beam smearing. We investigate the correlation between gas velocity dispersion and galaxy properties to understand the mechanisms that drive gas turbulence. We find that in both MAGPI and SAMI galaxies, the gas velocity dispersion more strongly correlates with the star-formation rate surface density (⁠|$\Sigma _{\rm SFR}$|⁠) than with a variety of other physical properties, and the average gas velocity dispersion is similar, at the same |$\Sigma _{\rm SFR}$|⁠ , for SAMI, MAGPI, and KROSS galaxies. The results indicate that mechanisms related to |$\Sigma _{\rm SFR}$| could be the dominant driver of gas turbulence from |$z\sim 1$| to |$z\sim 0$|⁠ , for example, stellar feedback and/or gravitational instability. The gas velocity dispersion of MAGPI galaxies is also correlated with the non-rotational motion of the gas, illustrating that in addition to star-formation feedback, gas transportation and accretion may also contribute to the gas velocity dispersion for galaxies at |$z\sim 0.3$|⁠. KROSS galaxies only have a moderate correlation between gas velocity dispersion and |$\Sigma _{\rm SFR}$| and a higher scatter of gas velocity dispersion with respect to |$\Sigma _{\rm SFR}$|⁠ , in agreement with the suggestion that other mechanisms, such as gas transportation and accretion, are relatively more important at higher redshift galaxies. [ABSTRACT FROM AUTHOR]

Stellar feedback-driven outflows are important regulators of the gas–star formation cycle. However, resolving outflow physics requires high-resolution observations that can only be achieved in very nearby galaxies, making suitable targets rare. We present the first results from the new VLT/MUSE large programme MAUVE (MUSE and ALMA Unveiling the Virgo Environment), which aims to understand the gas–star formation cycle within the context of the Virgo cluster environment. Outflows are a key part of this cycle, and we focus on the peculiar galaxy NGC 4383, which hosts a |$\sim\!\! 6\,$| kpc bipolar outflow fuelled by one of Virgo's most H  i -rich discs. The spectacular MUSE data reveal the clumpy structure and complex kinematics of the ionized gas in this M82-like outflow at 100 pc resolution. Using the ionized gas geometry and kinematics, we constrain the opening half-angle to θ = 25–35°, while the average outflow velocity is |$\sim\!\! 210\ \text{km} \, \text{s}^{-1}$|⁠. The emission line ratios reveal an ionization structure where photoionization is the dominant excitation process. The outflowing gas shows a marginally elevated gas-phase oxygen abundance compared to the disc but lower than the central starburst, highlighting the contribution of mixing between the ejected and entrained gas. Making some assumptions about the outflow geometry, we estimate an integrated mass outflow rate of |$\sim\!\! 1.8~\mathrm{M}_{\odot } \, \mathrm{yr}^{-1}$| and a corresponding mass-loading factor in the range of 1.7–2.3. NGC 4383 is a useful addition to the few nearby examples of well-resolved outflows, and will provide a useful baseline for quantifying the role of outflows within the Virgo cluster. [ABSTRACT FROM AUTHOR]

Geostatistical methods are powerful tools for understanding the spatial structure of the metallicity distribution of galaxies, and enable construction of accurate predictive models of the 2D metallicity distribution. However, so far these methods have only been applied to very high spatial resolution metallicity maps, leaving it uncertain if they will work on lower quality data. In this study, we apply geostatistical techniques to high-resolution spectroscopic maps of three local galaxies convolved to eight different spatial resolutions ranging from ∼40 pc to ∼1 kpc per pixel. We fit a geostatistical model to the data at all resolutions, and find that for metallicity maps where small-scale structure is visible by eye (with ≳10 resolution elements per R e), all parameters, including the metallicity correlation scale, can be recovered accurately. At all resolutions tested, we find that point metallicity predictions from such a geostatistical model outperform a circularly symmetric metallicity gradient model. We also explore dependence on the number of data points, and find that N ≳ 100 spatially resolved metallicity values are sufficient to train a geostatistical model that yields more accurate metallicity predictions than a radial gradient model. Finally, we investigate the potential detrimental effects of having spaxels smaller than an individual H  ii region by repeating our analysis with metallicities integrated over H  ii regions. We see that spaxel-based measurements have more noise, as expected, but the underlying spatial metallicity distribution can be recovered regardless of whether spaxels or integrated regions are used. [ABSTRACT FROM AUTHOR]

Spiral structures are important drivers of the secular evolution of disc galaxies, however, the origin of spiral arms and their effects on the development of galaxies remain mysterious. In this work, we present two three-armed spiral galaxies at z ∼ 0.3 in the Middle Age Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey. Taking advantage of the high spatial resolution (∼0.6 arcsec) of the Multi-Unit Spectroscopic Explorer (MUSE), we investigate the two-dimensional (2D) distributions of different spectral parameters: Hα, gas-phase metallicity, and D4000. We notice significant offsets in Hα (∼0.2 dex) and gas-phase metallicities (∼0.05 dex) among the spiral arms, downstream and upstream of MAGPI 1202197197 (SG 1202). This observational signature suggests the spiral structure in SG 1202 is consistent with arising from density wave theory. No azimuthal variation in Hα or gas-phase metallicities is observed in MAGPI 1204198199 (SG 1204), which can be attributed to the tighter spiral arms in SG 1204 than SG 1202, coming with stronger mixing effects in the disc. The absence of azimuthal D4000 variation in both galaxies suggests the stars at different ages are well mixed between the spiral arms and distributed around the disc regions. The different azimuthal distributions in Hα and D4000 highlight the importance of time-scales traced by various spectral parameters when studying 2D distributions in spiral galaxies. This work demonstrates the feasibility of constraining spiral structures by tracing interstellar medium (ISM) and stellar population at z ∼ 0.3, with a plan to expand the study to the full MAGPI survey. [ABSTRACT FROM AUTHOR]

We report spatially resolved dust properties of the quasar host galaxy BRI1335−0417 at redshift z  = 4.4 constrained by the Atacama Large Millimetre/submillimetre Array observations. The dust temperature map, derived from a greybody fit to rest frame 90 and 161 μ m continuum images, shows a steep increase towards the centre, reaching 57.1 ± 0.3 K and a flat median profile at the outer regions of ∼38 K. Image decomposition analysis reveals the presence of a point source in both dust continuum images spatially coincident with the highest temperature peak and the optical quasar position, which we attribute to warm dust heated by an active galactic nucleus (AGN). We show that a model including this warm component along with cooler dust heated by star formation describes the global spectral energy distribution better than a single-component model, with dust temperatures of 87.1 |$^{+34.1}_{-18.3}$| K (warm component) and 52.6 |$^{+10.3}_{-11.0}$| K (cold component). The star-formation rate (SFR) estimated from the cold dust component is |$1700_{-400}^{+500}\ \mathrm{M}_\odot$|  yr−1, a factor of three smaller than previous estimates due to a large AGN contribution (⁠|$53^{+14}_{-15}$| per cent). The unresolved warm dust component also explains the steep temperature gradient, as the temperature profile derived after the point source subtraction is flat. The point source subtraction also reduces the estimated central SFR surface density ΣSFR by over a factor of three. With this correction, spatially resolved measurements of ΣSFR and the surface gas mass density Σgas form a roughly linear sequence in the Kennicutt–Schmidt diagram with a constant gas depletion time of 50–200 Myr. The demonstrated AGN-host galaxy decomposition reveals the importance of spatially resolved data for accurate measurements of quasar host galaxy properties, including dust temperature, SFRs, and size. [ABSTRACT FROM AUTHOR]

Bars play an important role in mixing material in the inner regions of galaxies and stimulating radial migration. Previous observations have found evidence for the impact of a bar on metallicity gradients but the effect is still inconclusive. We use the TYPHOON/PrISM survey to investigate the metallicity gradients along and beyond the bar region across the entire star-forming disc of five nearby galaxies. Using emission line diagrams to identify star-forming spaxels, we recover the global metallicity gradients ranging from −0.0162 to −0.073 dex kpc−1 with evidence that the galactic bars act as an agent in affecting in situ star formation as well as the motions of gas and stars. We observe cases with a 'shallow-steep' metallicity radial profile, with evidence of the bar flattening the metallicity gradients inside the bar region (NGC 5068 and NGC 1566) and also note instances where the bar appears to drive a steeper metallicity gradient producing 'steep-shallow' metallicity profiles (NGC 1365 and NGC 1744). For NGC 2835, a 'steep-shallow' metallicity gradient break occurs at a distance ∼4 times the bar radius, which is more likely driven by gas accretion to the outskirt of the galaxy instead of the bar. The variation of metallicity gradients around the bar region traces the fluctuations of star formation rate surface density in NGC 1365, NGC 1566, and NGC 1744. A larger sample combined with hydrodynamical simulations is required to further explore the diversity, and the relative importance of different ISM mixing mechanisms on the gas-phase metallicity gradients in local galaxies. [ABSTRACT FROM AUTHOR]

The metallicity of diffuse ionized gas (DIG) cannot be determined using strong emission line diagnostics, which are calibrated to calculate the metallicity of H  ii regions. Because of this, resolved metallicity maps from integral field spectroscopy (IFS) data remain largely incomplete. In this paper (the second of a series), we introduce the geostatistical technique of universal kriging, which allows the complete 2D metallicity distribution of a galaxy to be reconstructed from metallicities measured at H  ii regions, accounting for spatial correlations between nearby data points. We apply this method to construct high-fidelity metallicity maps of the local spiral galaxy NGC 5236 using data from the TYPHOON/PrISM survey. We find significant correlation in the metallicity of H  ii regions separated by up to 0.4–1.2 kpc. Predictions constructed using this method were tested using cross-validation in H  ii regions, and we show that they outperform significantly interpolation based on metallicity gradients. Furthermore, we apply kriging to predict the metallicities in regions dominated by DIG emission, considering seven additional spiral galaxies with high resolution (≲100 pc) metallicity maps. We compare kriging maps to DIG metallicities computed with novel ionization corrections, and find that such corrections introduce a systematic offset of up to ±0.1 dex for any individual galaxy, with a scatter of 0.02–0.07 dex for the sample. Overall we recommend universal kriging, together with a calibrated geostatistical model, as the superior method for inferring the metallicities of DIG-dominated regions in local spiral galaxies, demonstrating further the potential of applying geostatistical methods to spatially resolved galaxy observations. [ABSTRACT FROM AUTHOR]