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We present the first statistical study of spatially integrated non-Gaussian stellar kinematics spanning 7 Gyr in cosmic time. We use deep, rest-frame optical spectroscopy of massive galaxies (stellar mass |$M_\star \gt 10^{10.5} \, \mathrm{M_\odot }$|⁠) at redshifts z = 0.05, 0.3, and 0.8 from the SAMI, MAGPI, and LEGA-C surveys, to measure the excess kurtosis h 4 of the stellar velocity distribution, the latter parametrized as a Gauss–Hermite series. We find that at all redshifts where we have large enough samples, h 4 anticorrelates with the ratio between rotation and dispersion, highlighting the physical connection between these two kinematic observables. In addition, and independently from the anticorrelation with rotation-to-dispersion ratio, we also find a correlation between h 4 and M ⋆, potentially connected to the assembly history of galaxies. In contrast, after controlling for mass, we find no evidence of independent correlation between h 4 and aperture velocity dispersion or galaxy size. These results hold for both star-forming and quiescent galaxies. For quiescent galaxies, h 4 also correlates with projected shape, even after controlling for the rotation-to-dispersion ratio. At any given redshift, star-forming galaxies have lower h 4 compared to quiescent galaxies, highlighting the link between kinematic structure and star-forming activity. [ABSTRACT FROM AUTHOR]

From a purely photometric perspective galaxies are generally decomposed into a bulge+disc system, with bulges being dispersion-dominated and discs rotationally supported. However, recent observations have demonstrated that such a framework oversimplifies complexity, especially if one considers galaxy kinematics. To address this issue we introduced with the GPU-based code bang a novel approach that employs analytical potential-density pairs as galactic components, allowing for a computationally fast, still reliable fit of the morphological and kinematic properties of galaxies. Here we apply bang to the SDSS-MaNGA survey, estimating key parameters such as mass, radial extensions, and dynamics, for both bulges and discs of +10 000 objects. We test our methodology against a smaller subsample of galaxies independently analysed with an orbit-based algorithm, finding agreement in the recovered total stellar mass. We also manage to reproduce well-established scaling relations, demonstrating how proper dynamical modelling can result in tighter correlations and provide corrections to standard approaches. Finally, we propose a more general way of decomposing galaxies into 'hot' and 'cold' components, showing a correlation with orbit-based approaches and visually determined morphological type. Unexpected tails in the 'hot-to-total' mass-ratio distribution are present for galaxies of all morphologies, possibly due to visual morphology misclassifications. [ABSTRACT FROM AUTHOR]

The observation of counter-rotation in galaxies (i.e. gas that rotates in the opposite direction to the stellar component or two cospatial stellar populations with opposite rotation) is becoming more commonplace with modern integral field spectroscopic surveys. In this paper, we explore the emergence of counter-rotation (both stellar and gaseous) in S0 galaxies from smoothed-particle hydrodynamics simulations of 1/10 mass ratio minor mergers between a ~1010.8 M⊙ disc galaxy with a bulge-to-total ratio of 0.17 and a gas-rich companion (gas-to-stellar mass fraction of 5.0). These simulations include a self-consistent treatment of gas dynamics, star formation, the production/destruction of H2 and dust and the time evolution of the interstellar radiation field. We explore the effect of retrograde versus prograde obits, gas and bulge mass fractions of the primary galaxy, and orbital parameters of the companion. The key requirement for producing counter-rotation in stars or gas in a merger remnant is a retrograde primary, while the relative spin of the companion affects only the radial extent of the accreted gas. We also find that including a significant amount of gas in the primary can prevent the emergence of counter-rotating gas, although accreted stars retain counter-rotation. Bulge mass and orbit have a secondary effect, generally influencing the final distribution of accreted stars and gas within the framework outlined above. In addition to our primary focus of counter-rotating components in galaxies, we also make some predictions regarding the SFRs, H2 distributions, and dust in minor-merger remnants. [ABSTRACT FROM AUTHOR]

We present first results from the KMOS Ultra-deep Rotation Velocity Survey (KURVS), aimed at studying the outer rotation curves shape and dark matter content of 22 star-forming galaxies at z ∼ 1.5. These galaxies represent 'typical' star-forming discs at z ∼ 1.5, being located within the star-forming main sequence and stellar mass-size relation with stellar masses 9.5 ≤ log(M ⋆/M⊙) ≤ 11.5. We use the spatially resolved H α emission to extract individual rotation curves out to 4 times the effective radius, on average, or ∼10–15 kpc. Most rotation curves are flat or rising between three and six disc scale radii. Only three objects with dispersion-dominated dynamics (v rot/σ0 ∼ 0.2) have declining outer rotation curves at more than 5σ significance. After accounting for seeing and pressure support, the nine rotation-dominated discs with v rot/σ0 ≥ 1.5 have average dark matter fractions of |$50 \pm 20{{\ \rm per\ cent}}$| at the effective radius, similar to local discs. Together with previous observations of star-forming galaxies at cosmic noon, our measurements suggest a trend of declining dark matter fraction with increasing stellar mass and stellar mass surface density at the effective radius. Measurements of simulated EAGLE galaxies are in quantitative agreement with observations up to log |$(M_{\star } R_{\rm eff}^{-2} /\mathrm{M_{\odot } kpc^{-2}}) \sim 9.2$|⁠ , and overpredict the dark matter fraction of galaxies with higher mass surface densities by a factor of ∼3. We conclude that the dynamics of typical rotationally-supported discs at z ∼ 1.5 is dominated by dark matter from effective radius scales, in broad agreement with cosmological models. The tension with observations at high stellar mass surface density suggests that the prescriptions for baryonic processes occurring in the most massive galaxies (such as bulge growth and quenching) need to be reassessed. [ABSTRACT FROM AUTHOR]

NGC 5291, an early-type galaxy surrounded by a giant H  i ring, is believed to be formed from collision with another galaxy. Several star forming complexes and tidal dwarf galaxies are distributed along the collisional ring which are sites of star formation in environments where extreme dynamical effects are involved. Dynamical effects can affect the star formation properties and the spatial distribution of star forming complexes along the tidal features. To study and quantify the star formation activity in the main body and in the ring structure of the NGC 5291 system, we use high spatial resolution FUV and NUV imaging observations from the Ultraviolet Imaging Telescope onboard AstroSat. A total of 57 star-forming knots are identified to be part of this interacting system out of which 12 are new detections (star forming complexes that lie inside the H  i contour) compared to the previous measurements from lower resolution UV imaging. We estimate the attenuation in UV for each of the resolved star-forming knots using the UV spectral slope β, derived from the FUV − NUV colour. Using the extinction corrected UV fluxes, we derive the star formation rate of the resolved star forming complexes. The extinction corrected total star formation rate of this system is estimated as 1.75 ± 0.04 |$\mathrm{M_\odot \, yr}^{-1}$|⁠. The comparison with dwarf galaxy populations (BCD, Sm, and dIm galaxies) in the nearby Universe shows that many of the knots in the NGC 5291 system have SFR values comparable to the SFR of BCD galaxies. [ABSTRACT FROM AUTHOR]

Aims. In this Virgo Environment Traced in CO (VERTICO) science paper, we aim to study how the star formation process depends on the galactic environment and gravitational interactions in the context of galaxy evolution. We explore the scaling relation between the star formation rate surface density (ΣSFR) and the molecular gas surface density (Σmol), also known as the Kennicutt-Schmidt relation, in a subsample of Virgo cluster spiral galaxies. Methods. We used new Atacama Compact Array and Total Power (ACA+TP) observations from the VERTICO-Atacama Large Millimeter/submillimeter Array (ALMA) Large Program at 720 pc resolution to resolve the molecular gas content, as traced by the 12CO (2 − 1) transition, across the disks of 37 spiral galaxies in the Virgo cluster. In combination with archival UV and IR observations used to determine the star formation rate (SFR), we estimated the parameters of the Kennicutt-Schmidt (KS) relation for the entire ensemble of galaxies, and within individual galaxies. Results. We find the KS slope for the entire population to be N = 0.97 ± 0.07, with a characteristic molecular gas depletion time of 1.86 Gyr for our full sample, which is in agreement with previous work in isolated, nearby star-forming galaxies. In individual galaxies, we find that the KS slope ranges between 0.69 and 1.40, and that typical star formation efficiencies of molecular gas can vary from galaxy to galaxy by a factor of ∼4. These galaxy-to-galaxy variations account for ∼0.20 dex in scatter in the ensemble KS relation, which is characterized by a 0.42 dex scatter. In addition, we find that the HI-deficient galaxies in the Virgo cluster show a steeper resolved KS relation and lower molecular gas efficiencies than HI-normal cluster galaxies. Conclusions. While the molecular gas content in galaxies residing in the Virgo cluster appears – to first order – to behave similarly to that in isolated galaxies, our VERTICO sample of galaxies shows that cluster environments play a key role in regulating star formation. The environmental mechanisms affecting the HI galaxy content also have a direct impact on the star formation efficiency of molecular gas in cluster galaxies, leading to longer depletion times in HI-deficient members. [ABSTRACT FROM AUTHOR]

Gas-phase metallicities of galaxies are typically measured through auroral or nebular emission lines, but metallicity also leaves an imprint on the overall spectral energy distribution (SED) of a galaxy and can be estimated through SED fitting. We use the ProSpect SED fitting code with a flexible parametric star formation history and an evolving metallicity history to self-consistently measure metallicities, stellar mass, and other galaxy properties for |$\sim 90\, 000$| galaxies from the Deep Extragalactic VIsible Legacy Survey (DEVILS) and Galaxy and Mass Assembly (GAMA) survey. We use these to trace the evolution of the mass–metallicity relation (MZR) and show that the MZR only evolves in normalization by |$\sim 0.1\,$| dex at stellar mass |$M_\star = 10^{10.5}\, \mathrm{M}_\odot$|⁠. We find no difference in the MZR between galaxies with and without SED evidence of active galactic nuclei emission at low redshifts (⁠|$z$| < 0.3). Our results suggest an anticorrelation between metallicity and star formation activity at fixed stellar mass for galaxies with |$M_\star \gt 10^{10.5}\, \mathrm{M}_\odot$| for |$z$| < 0.3. Using the star formation histories extracted using ProSpect we explore higher order correlations of the MZR with properties of the star formation history including age, width, and shape. We find that at a given stellar mass, galaxies with higher metallicities formed most of their mass over shorter time-scales, and before their peak star formation rate. This work highlights the value of exploring the connection of a galaxy's current gas-phase metallicity to its star formation history in order to understand the physical processes shaping the MZR. [ABSTRACT FROM AUTHOR]

In this work, we investigate how the central stellar metallicity ([Z/H]) of 1363 galaxies from the SAMI galaxy survey is related to their stellar mass and a proxy for the gravitational potential, |$\Phi = \log _{10}\left(\frac{M_*}{M_{\odot }} \right) - \log _{10}\left(\frac{r_e}{\mathrm{kpc}} \right)$|⁠. In agreement with previous studies, we find that passive and star-forming galaxies occupy different areas of the [Z/H]– M * plane, with passive galaxies having higher [Z/H] than star-forming galaxies at fixed mass (a difference of 0.23 dex at log10(M */M⊙) = 10.3). We show for the first time that all galaxies lie on the same relation between [Z/H] and Φ, and show that the offset in [Z/H] between passive and star-forming galaxies at fixed Φ is smaller than or equal to the offset in [Z/H] at fixed mass (an average Δ[Z/H] of 0.11 dex at fixed Φ compared to 0.21 dex at fixed mass). We then build a simple model of galaxy evolution to explain and understand our results. By assuming that [Z/H] traces Φ over cosmic time and that the probability that a galaxy quenches depends on both its mass and size, we are able to reproduce these offsets in stellar metallicity with a model containing instantaneous quenching. We therefore conclude that an offset in metallicity at fixed mass cannot by itself be used as evidence of slow quenching processes, in contrast to previous studies. Instead, our model implies that metal-rich galaxies have always been the smallest objects for their mass in a population. Our findings reiterate the need to consider galaxy size when studying stellar populations. [ABSTRACT FROM AUTHOR]

Using the eagle (Evolution and Assembly of GaLaxies and their Environments) suite of simulations, we demonstrate that both cold gas stripping and starvation of gas inflow play an important role in quenching satellite galaxies across a range of stellar and halo masses, M ⋆ and M 200. Quantifying the balance between gas inflows, outflows, and star formation rates, we show that even at z  = 2, only |$\approx 30{{\ \rm per\ cent}}$| of satellite galaxies are able to maintain equilibrium or grow their reservoir of cool gas – compared to |$\approx 50{{\ \rm per\ cent}}$| of central galaxies at this redshift. We find that the number of orbits completed by a satellite on first-infall to a group environment is a very good predictor of its quenching, even more so than the time since infall. On average, we show that intermediate-mass satellites with M ⋆ between will be quenched at |$10^{9}\, {\rm M}_{\odot }\, {\rm and}\, 10^{10}\, {\rm M}_{\odot }$| first pericenter in massive group environments, |$M_{200}\gt 10^{13.5}\, {\rm M}_{\odot }$|⁠ ; and will be quenched at second pericenter in less massive group environments, |$M_{200}\lt 10^{13.5}\, {\rm M}_{\odot }$|⁠. On average, more massive satellites (⁠|$M_{\star }\gt 10^{10}\, {\rm M}_{\odot }$|⁠) experience longer depletion time-scales, being quenched between first and second pericenters in massive groups, while in smaller group environments, just |$\approx 30{{\ \rm per\ cent}}$| will be quenched even after two orbits. Our results suggest that while starvation alone may be enough to slowly quench satellite galaxies, direct gas stripping, particularly at pericenters, is required to produce the short quenching time-scales exhibited in the simulation. [ABSTRACT FROM AUTHOR]

In this VERTICO early science paper we explore in detail how environmental mechanisms, identified in H i, affect the resolved properties of molecular gas reservoirs in cluster galaxies. The molecular gas is probed using ALMA ACA (+TP) observations of 12CO(2â€"1) in 51 spiral galaxies in the Virgo cluster (of which 49 are detected), all of which are included in the VIVA H i survey. The sample spans a stellar mass range of 9 ≤ log M ⋆ / M ⊙ ≤ 11. We study molecular gas radial profiles, isodensity radii, and surface densities as a function of galaxy H i deficiency and morphology. There is a weak correlation between global H i and H2 deficiencies, and resolved properties of molecular gas correlate with H i deficiency: galaxies that have large H i deficiencies have relatively steep and truncated molecular gas radial profiles, which is due to the removal of low-surface-density molecular gas on the outskirts. Therefore, while the environmental mechanisms observed in H i also affect molecular gas reservoirs, there is only a moderate reduction of the total amount of molecular gas. [ABSTRACT FROM AUTHOR]

We investigate changes in stellar population age and metallicity ([Z/H]) scaling relations for quiescent galaxies from intermediate redshift (0.60 ≤   |$z$| ≤ 0.76) using the LEGA-C Survey to low redshift (0.014 ≤   |$z$| ≤ 0.10) using the SAMI Galaxy Survey. Specifically, we study how the spatially integrated global age and metallicity of individual quiescent galaxies vary in the mass–size plane, using the stellar mass M * and a dynamical mass proxy derived from the virial theorem M D  ∝ σ2  R e. We find that, similarly to at low redshift, the metallicity of quiescent galaxies at 0.60 ≤   |$z$| ≤ 0.76 closely correlates with M / R e (a proxy for the gravitational potential or escape velocity), in that galaxies with deeper potential wells are more metal-rich. This supports the hypothesis that the relation arises due to the gravitational potential regulating the retention of metals by determining the escape velocity for metal-rich stellar and supernova ejecta to escape the system and avoid being recycled into later stellar generations. Conversely, we find no correlation between age and surface density (⁠|$M/R_\mathrm{e}^2$|⁠) at 0.60 ≤   |$z$| ≤ 0.76, despite this relation being strong at low redshift. We consider this change in the age– |$M/R_\mathrm{e}^2$| relation in the context of the redshift evolution of the star-forming and quiescent mass–size relations, and find our results are consistent with galaxies forming more compactly at higher redshifts and remaining compact throughout their evolution. Furthermore, galaxies appear to quench at a characteristic surface density that decreases with decreasing redshift. The |$z$| ∼  0 age– |$M/R_\mathrm{e}^2$| relation is therefore a result of building up the quiescent and star-forming populations with galaxies that formed at a range of redshifts and therefore a range of surface densities. [ABSTRACT FROM AUTHOR]

We investigate the mean locally measured velocity dispersions of ionized gas (σgas) and stars (σ*) for 1090 galaxies with stellar masses |$\log \, (M_{\!\ast }/M_{\odot }) \ge 9.5$| from the SAMI Galaxy Survey. For star-forming galaxies, σ* tends to be larger than σgas, suggesting that stars are in general dynamically hotter than the ionized gas (asymmetric drift). The difference between σgas and σ* (Δσ) correlates with various galaxy properties. We establish that the strongest correlation of Δσ is with beam smearing, which inflates σgas more than σ*, introducing a dependence of Δσ on both the effective radius relative to the point spread function and velocity gradients. The second strongest correlation is with the contribution of active galactic nuclei (AGN) (or evolved stars) to the ionized gas emission, implying that the gas velocity dispersion is strongly affected by the power source. In contrast, using the velocity dispersion measured from integrated spectra (σap) results in less correlation between the aperture-based Δσ (Δσap) and the power source. This suggests that the AGN (or old stars) dynamically heat the gas without causing significant deviations from dynamical equilibrium. Although the variation of Δσap is much smaller than that of Δσ, a correlation between Δσap and gas velocity gradient is still detected, implying that there is a small bias in dynamical masses derived from stellar and ionized gas velocity dispersions. [ABSTRACT FROM AUTHOR]

The kinematic morphology–density relation of galaxies is normally attributed to a changing distribution of galaxy stellar masses with the local environment. However, earlier studies were largely focused on slow rotators; the dynamical properties of the overall population in relation to environment have received less attention. We use the SAMI Galaxy Survey to investigate the dynamical properties of ∼1800 early and late-type galaxies with log (M ⋆/ M ⊙) > 9.5 as a function of mean environmental overdensity (Σ5) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above log (M ⋆/ M ⊙) > 10.5, we detect a higher fraction (∼3.4σ) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. We find similar results when using Σ5 as a tracer for environment. Focusing on the fast-rotator population, we also detect a significant correlation between galaxy kinematics and their stellar mass as well as the environment they are in. Specifically, by using inclination-corrected or intrinsic |$\lambda _{R_{\rm {e}}}$| values, we find that, at fixed mass, satellite galaxies on average have the lowest |$\lambda _{\, R_{\rm {e}},\rm {intr}}$|⁠ , isolated-central galaxies have the highest |$\lambda _{\, R_{\rm {e}},\rm {intr}}$|⁠ , and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean |$\lambda _{\, R_{\rm {e}},\rm {intr}}$| values as compared to galaxies at low environmental density. However, at fixed Σ5, the mean |$\lambda _{\, R_{\rm {e}},\rm {intr}}$| differences for low and high-mass galaxies are of similar magnitude as when varying Σ5 (⁠|$\Delta \lambda _{\, R_{\rm {e}},\rm {intr}} \sim 0.05$|⁠ , with σrandom = 0.025, and σ syst < 0.03). Our results demonstrate that after stellar mass, environment plays a significant role in the creation of slow rotators, while for fast rotators we also detect an independent, albeit smaller, impact of mass and environment on their kinematic properties. [ABSTRACT FROM AUTHOR]

We present redshift-zero synthetic observational data considering dust attenuation and dust emission for the 30 galaxies of the Auriga project, calculated with the skirt radiative transfer code. The post-processing procedure includes components for star-forming regions, stellar sources, and diffuse dust taking into account stochastic heating of dust grains. This allows us to obtain realistic high-resolution broad-band images and fluxes from ultraviolet (UV) to submillimetre (submm) wavelengths. For the diffuse dust component, we consider two mechanisms for assigning dust to gas cells in the simulation. In one case, only the densest or the coldest gas cells are allowed to have dust, while in the other case this condition is relaxed to allow a larger number of dust-containing cells. The latter approach yields galaxies with a larger radial dust extent and an enhanced dust presence in the interspiral regions. At a global scale, we compare Auriga galaxies with observations by deriving dust scaling relations using spectral energy distribution fitting. At a resolved scale, we make a multiwavelength morphological comparison with nine well-resolved spiral galaxies from the DustPedia observational data base. We find that for both dust assignment methods, although the Auriga galaxies show a good overall agreement with observational dust properties, they exhibit a slightly higher specific dust mass. The multiwavelength morphological analysis reveals a good agreement between the Auriga and the observed galaxies in the optical wavelengths. In the mid- and far-infrared wavelengths, Auriga galaxies appear smaller and more centrally concentrated in comparison to their observed counterparts. We publicly release the multi-observer images and fluxes in 50 commonly used broad-band filters. [ABSTRACT FROM AUTHOR]

We have entered a new era where integral-field spectroscopic surveys of galaxies are sufficiently large to adequately sample large-scale structure over a cosmologically significant volume. This was the primary design goal of the SAMI Galaxy Survey. Here, in Data Release 3, we release data for the full sample of 3068 unique galaxies observed. This includes the SAMI cluster sample of 888 unique galaxies for the first time. For each galaxy, there are two primary spectral cubes covering the blue (370–570 nm) and red (630–740 nm) optical wavelength ranges at spectral resolving power of R = 1808 and 4304, respectively. For each primary cube, we also provide three spatially binned spectral cubes and a set of standardized aperture spectra. For each galaxy, we include complete 2D maps from parametrized fitting to the emission-line and absorption-line spectral data. These maps provide information on the gas ionization and kinematics, stellar kinematics and populations, and more. All data are available online through Australian Astronomical Optics Data Central. [ABSTRACT FROM AUTHOR]

We measure the gas-phase metallicity gradients of 248 galaxies selected from Data Release 2 of the SAMI Galaxy Survey. We demonstrate that there are large systematic discrepancies between the metallicity gradients derived using common strong emission line metallicity diagnostics. We determine which pairs of diagnostics have Spearman's rank coefficients greater than 0.6 and provide linear conversions to allow the accurate comparison of metallicity gradients derived using different strong emission line diagnostics. For galaxies within the mass range 8.5 < log (M /M⊙) < 11.0, we find discrepancies of up to 0.11 dex/ R e between seven popular diagnostics in the metallicity gradient–mass relation. We find a suggestion of a break in the metallicity gradient–mass relation, where the slope shifts from negative to positive, occurs between 9.5 < log (M /M⊙) < 10.5 for the seven chosen diagnostics. Applying our conversions to the metallicity gradient–mass relation, we reduce the maximum dispersion from 0.11 dex/ R e to 0.02 dex/ R e. These conversions provide the most accurate method of converting metallicity gradients when key emission lines are unavailable. We find that diagnostics that share common sets of emission line ratios agree best, and that diagnostics calibrated through the electron temperature provide more consistent results compared to those calibrated through photoionization models. [ABSTRACT FROM AUTHOR]

We study the stellar and gas kinematics of the brightest group galaxies (BGGs) in dynamically relaxed and unrelaxed galaxy groups for a sample of 154 galaxies in the SAMI galaxy survey. We characterize the dynamical state of the groups using the luminosity gap between the two most luminous galaxies and the BGG offset from the luminosity centroid of the group. We find that the misalignment between the rotation axis of gas and stellar components is more frequent in the BGGs in unrelaxed groups, although with quite low statistical significance. Meanwhile, galaxies whose stellar dynamics would be classified as "regular rotators" based on their kinemetry are more common in relaxed groups. We confirm that this dependency on group dynamical state remains valid at fixed stellar mass and Sérsic index. The observed trend could potentially originate from a differing BGG accretion history in virialized and evolving groups. Among the halo relaxation probes, the group BGG offset appears to play a stronger role than the luminosity gap on the stellar kinematic differences of the BGGs. However, both the group BGG offset and luminosity gap appear to roughly equally drive the misalignment between the gas and stellar component of the BGGs in one direction. This study offers the first evidence that the dynamical state of galaxy groups may influence the BGG's stellar and gas kinematics, and we call for further studies using a larger sample with higher signal-to-noise. [ABSTRACT FROM AUTHOR]

Observations of the cold neutral atomic hydrogen (H  i) in and around disc galaxies have revealed that spatial and kinematic asymmetries are common place, and are reflected in the global H  i spectra. We use the TNG100 box from the IllustrisTNG suite of cosmological simulations to study the conditions under which these asymmetries may arise in current theoretical galaxy formation models. We find that more than 50 per cent of the sample has at least a 10 per cent difference in integrated flux between the high- and low-velocity half of the spectrum, thus the typical TNG100 galaxy has an H  i profile that is not fully symmetric. We find that satellite galaxies are a more asymmetric population than centrals, consistent with observational results. Using halo mass as a proxy for environment, this trend appears to be driven by the satellite population within the virial radius of haloes more massive than 1013 M⊙, typical of medium/large groups. We show that, while the excess of H  i asymmetry in group satellites is likely driven by ram pressure, the bulk of the asymmetric H  i profiles observed in TNG100 are driven by physical processes able to affect both the central and satellite populations. Our results highlight how asymmetries are not driven solely by environment, and multiple physical processes can produce the same asymmetric shape in global H  i spectra. [ABSTRACT FROM AUTHOR]

The Study of H α from Dwarf Emissions (SHαDE) is a high spectral resolution (R = 13 500) H α integral field survey of 69 dwarf galaxies with stellar masses 106 < M ⋆ < 109 M⊙. The survey used FLAMES on the ESO Very Large Telescope. SHαDE is designed to study the kinematics and stellar populations of dwarf galaxies using consistent methods applied to massive galaxies and at matching level of detail, connecting these mass ranges in an unbiased way. In this paper, we set out the science goals of SHαDE, describe the sample properties, outline the data reduction, and analysis processes. We investigate the log  M ⋆–log  S 0.5 mass–kinematics scaling relation, which has previously shown potential for combining galaxies of all morphologies in a single scaling relation. We extend the scaling relation from massive galaxies to dwarf galaxies, demonstrating this relation is linear down to a stellar mass of M ⋆ ∼ 108.6 M⊙. Below this limit, the kinematics of galaxies inside one effective radius appears to be dominated by the internal velocity dispersion limit of the H α-emitting gas, giving a bend in the log  M ⋆–log  S 0.5 relation. Replacing stellar mass with total baryonic mass using gas mass estimate reduces the severity but does not remove the linearity limit of the scaling relation. An extrapolation to estimate the galaxies' dark matter halo masses, yields a log  M h–log  S 0.5 scaling relation that is free of any bend, has reduced curvature over the whole mass range, and brings galaxies of all masses and morphologies on to the virial relation. [ABSTRACT FROM AUTHOR]

It has been proposed that S0 galaxies are either fading spirals or the result of galaxy mergers. The relative contribution of each pathway and the environments in which they occur remain unknown. Here, we investigate stellar and gas kinematics of 219 S0s in the SAMI Survey to look for signs of multiple formation pathways occurring across the full range of environments. We identify a large range of rotational support in their stellar kinematics, which correspond to ranges in their physical structure. We find that pressure-supported S0s with v / σ below 0.5 tend to be more compact and feature misaligned stellar and gas components, suggesting an external origin for their gas. We postulate that these S0s are consistent with being formed through a merger process. Meanwhile, comparisons of ellipticity, stellar mass, and Sérsic index distributions with spiral galaxies show that the rotationally supported S0s with v / σ above 0.5 are more consistent with a faded spiral origin. In addition, a simulated merger pathway involving a compact elliptical and gas-rich satellite results in an S0 that lies within the pressure-supported group. We conclude that two S0 formation pathways are active, with mergers dominating in isolated galaxies and small groups, and the faded spiral pathway being most prominent in large groups (⁠|$10^{13}\lt \rm {M_{halo}}\lt 10^{14}$|⁠). [ABSTRACT FROM AUTHOR]

We present a comparison of galaxy atomic and molecular gas properties in three recent cosmological hydrodynamic simulations, namely SIMBA, EAGLE, and IllustrisTNG, versus observations from z ∼ 0 to 2. These simulations all rely on similar subresolution prescriptions to model cold interstellar gas that they cannot represent directly, and qualitatively reproduce the observed z ≈ 0 H  i and H2 mass functions (HIMFs and H2MFs, respectively), CO(1–0) luminosity functions (COLFs), and gas scaling relations versus stellar mass, specific star formation rate, and stellar surface density μ*, with some quantitative differences. To compare to the COLF, we apply an H2-to-CO conversion factor to the simulated galaxies based on their average molecular surface density and metallicity, yielding substantial variations in αCO and significant differences between models. Using this, predicted z = 0 COLFs agree better with data than predicted H2MFs. Out to z ∼ 2, EAGLE's and SIMBA's HIMFs and COLFs strongly increase, while IllustrisTNG's HIMF declines and COLF evolves slowly. EAGLE and simba reproduce high- L CO(1–0) galaxies at z ∼ 1–2 as observed, owing partly to a median αCO(z = 2) ∼ 1 versus αCO(z = 0) ∼ 3. Examining H  i , H2, and CO scaling relations, their trends with M * are broadly reproduced in all models, but EAGLE yields too little H  i in green valley galaxies, IllustrisTNG and SIMBA overproduce cold gas in massive galaxies, and SIMBA overproduces molecular gas in small systems. Using SIMBA variants that exclude individual active galactic nucleus (AGN) feedback modules, we find that SIMBA's AGN jet feedback is primarily responsible by lowering cold gas contents from z ∼ 1 → 0 by suppressing cold gas in |$M_*\gtrsim 10^{10}{\rm \,M}_\odot$| galaxies, while X-ray feedback suppresses the formation of high-μ* systems. [ABSTRACT FROM AUTHOR]

We present the KMOS-CLASH (K-CLASH) survey, a K -band Multi-Object Spectrograph (KMOS) survey, of the spatially resolved gas properties and kinematics of 191 (pre-dominantly blue) H α-detected galaxies at 0.2 ≲ z ≲ 0.6 in field and cluster environments. K-CLASH targets galaxies in four Cluster Lensing And Supernova survey with Hubble (CLASH) fields in the KMOS IZ -band, over 7 arcmin radius (≈2–3 Mpc) fields of view. K-CLASH aims to study the transition of star-forming galaxies from turbulent, highly star-forming disc-like and peculiar systems at z ≈ 1–3, to the comparatively quiescent, ordered late-type galaxies at z ≈ 0, and to examine the role of clusters in the build-up of the red sequence since z ≈ 1. In this paper, we describe the K-CLASH survey, present the sample, and provide an overview of the K-CLASH galaxy properties. We demonstrate that our sample comprises star-forming galaxies typical of their stellar masses and epochs, residing both in field and cluster environments. We conclude K-CLASH provides an ideal sample to bridge the gap between existing large integral-field spectroscopy surveys at higher and lower redshifts. We find that star-forming K-CLASH cluster galaxies at intermediate redshifts have systematically lower stellar masses than their star-forming counterparts in the field, hinting at possible 'downsizing' scenarios of galaxy growth in clusters at these epochs. We measure no difference between the star formation rates of H α-detected, star-forming galaxies in either environment after accounting for stellar mass, suggesting that cluster quenching occurs very rapidly during the epochs probed by K-CLASH, or that star-forming K-CLASH galaxies in clusters have only recently arrived there, with insufficient time elapsed for quenching to have occurred. [ABSTRACT FROM AUTHOR]

We investigate the stellar kinematics of the bulge and disk components in 826 galaxies with a wide range of morphology from the Sydney-AAO Multi-object Integral-field spectroscopy Galaxy Survey. The spatially resolved rotation velocity (V) and velocity dispersion (σ) of bulge and disk components have been simultaneously estimated using the penalized pixel fitting (ppxf) method with photometrically defined weights for the two components. We introduce a new subroutine of ppxf for dealing with degeneracy in the solutions. We show that the V and σ distributions in each galaxy can be reconstructed using the kinematics and weights of the bulge and disk components. The combination of two distinct components provides a consistent description of the major kinematic features of galaxies over a wide range of morphological types. We present Tully–Fisher and Faber–Jackson relations showing that the galaxy stellar mass scales with both V and σ for both components of all galaxy types. We find a tight Faber–Jackson relation even for the disk component. We show that the bulge and disk components are kinematically distinct: (1) the two components show scaling relations with similar slopes, but different intercepts; (2) the spin parameter λ R indicates bulges are pressure-dominated systems and disks are supported by rotation; and (3) the bulge and disk components have, respectively, low and high values in intrinsic ellipticity. Our findings suggest that the relative contributions of the two components explain, at least to first order, the complex kinematic behaviour of galaxies. [ABSTRACT FROM AUTHOR]

We infer the intrinsic ionized gas kinematics for 383 star-forming galaxies across a range of integrated star formation rates (SFR ∈ [10−3, 102] M⊙ yr−1) at z ≲ 0.1 using a consistent 3D forward-modelling technique. The total sample is a combination of galaxies from the Sydney-AAO Multiobject Integral field Spectrograph (SAMI) Galaxy survey and DYnamics of Newly Assembled Massive Objects survey. For typical low- z galaxies taken from the SAMI Galaxy Survey, we find the vertical velocity dispersion (σ v,z ) to be positively correlated with measures of SFR, stellar mass, H  i gas mass, and rotational velocity. The greatest correlation is with SFR surface density (ΣSFR). Using the total sample, we find σ v,z increases slowly as a function of integrated SFR in the range SFR ∈ [10−3, 1]  M⊙ yr−1 from 17 ± 3 to 24 ± 5 km s−1 followed by a steeper increase up to σ v,z ∼80 km s−1 for SFR ≳ 1 M⊙ yr−1. This is consistent with recent theoretical models that suggest a σ v,z floor driven by star formation feedback processes with an upturn in σ v,z at higher SFR driven by gravitational transport of gas through the disc. [ABSTRACT FROM AUTHOR]

We present an overview of recent key results from the SAMI Galaxy Survey on the build-up of mass and angular momentum in galaxies across morphology and environment. The SAMI Galaxy survey is a multi-object integral field spectroscopic survey and provides a wealth of spatially-resolved, two-dimensional stellar and gas measurements for galaxies of all morphological types, with high-precision due the stable spectral resolution of the AAOmega spectrograph. The sample size of ~3000 galaxies allows for dividing the sample in bins of stellar mass, environment, and star-formation or morphology, whilst maintaining a statistical significant number of galaxies in each bin. By combining imaging, spatially resolved dynamics, and stellar population measurements, our result demonstrate the power of utilising integral field spectroscopy on a large sample of galaxies to further our understanding of physical processes involved in the build-up of stellar mass and angular momentum in galaxies. [ABSTRACT FROM AUTHOR]

Recent studies of neutral atomic hydrogen (H  i) in nearby galaxies found that all field disc galaxies are H  i saturated, in that they carry roughly as much H  i as permitted before this gas becomes gravitationally unstable. By taking this H  i saturation for granted, the atomic gas fraction f atm of galactic discs can be predicted as a function of the stability parameter q  = j σ/(GM), where M and j are the baryonic mass and specific angular momentum of the disc and σ is the H  i velocity dispersion (Obreschkow et al. 2016). The log-ratio Δ fq between this predictor and the observed atomic fraction can be seen as a physically motivated 'H  i deficiency'. While field disc galaxies have Δ fq ≈ 0, objects subject to environmental removal of H  i are expected to have Δ fq > 0. Within this framework, we revisit the H  i deficiencies of satellite galaxies in the Virgo cluster and in clusters of the EAGLE simulation. We find that observed and simulated cluster galaxies are H  i deficient and that Δ fq slightly increases when getting closer to the cluster centres. The Δ fq values are similar to traditional H  i deficiency estimators, but Δ fq is more directly comparable between observations and simulations than morphology-based–deficiency estimators. By tracking the simulated H  i deficient cluster galaxies back in time, we confirm that Δ fq ≈ 0 until the galaxies first enter a halo with |$M_{\rm halo}\gt 10^{13}\rm M_{\odot }$|⁠ , at which moment they quickly lose H  i by environmental effects. Finally, we use the simulation to investigate the links between Δ fq and quenching of star formation. [ABSTRACT FROM AUTHOR]

The Galaxy And Mass Assembly (GAMA) survey has morphologically identified a class of 'Little Blue Spheroid' (LBS) galaxies whose relationship to other classes of galaxies we now examine in detail. Considering a sample of 868 LBSs, we find that such galaxies display similar but not identical colours, specific star formation rates, stellar population ages, mass-to-light ratios, and metallicities to Sd-Irr galaxies. We also find that LBSs typically occupy environments of even lower density than those of Sd-Irr galaxies, where ∼65 per cent of LBS galaxies live in isolation. Using deep, high-resolution imaging from VST KiDS and the new Bayesian, 2D galaxy profile modelling code profit , we further examine the detailed structure of LBSs and find that their Sérsic indices, sizes, and axial ratios are compatible with those of low-mass elliptical galaxies. We then examine SAMI Galaxy survey integral field emission line kinematics for a subset of 62 LBSs and find that the majority (42) of these galaxies display ordered rotation with the remainder displaying disturbed/non-ordered dynamics. Finally, we consider potential evolutionary scenarios for a population with this unusual combination of properties, concluding that LBSs are likely formed by a mixture of merger and accretion processes still recently active in low-redshift dwarf populations. We also infer that if LBS-like galaxies were subjected to quenching in a rich environment, they would plausibly resemble cluster dwarf ellipticals. [ABSTRACT FROM AUTHOR]

Using a spectral stacking technique, we measure the neutral hydrogen (H  i) properties of a sample of galaxies at z < 0.11 across 35 pointings of the Westerbork Synthesis Radio Telescope. The radio data contain 1895 galaxies with redshifts and positions known from the Sloan Digital Sky Survey. We carefully quantified the effects of sample bias, aperture used to extract spectra, sidelobes and weighting technique and use our data to provide a new estimate for the cosmic H  i mass density. We find a cosmic H  i mass density of |$\Omega _{\rm H\,{\small I}} = (4.02 \pm 0.26)\times 10^{-4} h_{70}^{-1}$| at 〈 z 〉 = 0.066, consistent with measurements from blind H  i surveys and other H  i stacking experiments at low redshifts. The combination of the small interferometer beam size and the large survey volume makes our result highly robust against systematic effects due to confusion at small scales and cosmic variance at large scales. Splitting into three sub-samples with 〈 z 〉 = 0.038, 0.067, and 0.093 shows no significant evolution of the H  i gas content at low redshift. [ABSTRACT FROM AUTHOR]

We use data from the Sydney-AAO Multi-object Integral-field spectroscopy (SAMI) Galaxy Survey to study the dynamical scaling relation between galaxy stellar mass M ∗ and the general kinematic parameter |$S_K = \sqrt{K V_{\rm rot}^2 + \sigma ^2}$| that combines rotation velocity V rot and velocity dispersion σ. We show that the log  M ∗ – log  SK relation: (1) is linear above limits set by properties of the samples and observations; (2) has slightly different slope when derived from stellar or gas kinematic measurements; (3) applies to both early-type and late-type galaxies and has smaller scatter than either the Tully–Fisher relation (log  M ∗ − log  V rot) for late types or the Faber–Jackson relation (log  M ∗ − log σ) for early types; and (4) has scatter that is only weakly sensitive to the value of K , with minimum scatter for K in the range 0.4 and 0.7. We compare SK to the aperture second moment (the 'aperture velocity dispersion') measured from the integrated spectrum within a 3-arcsecond radius aperture (⁠|$\sigma _{3^{\prime \prime }}$|⁠). We find that while SK and |$\sigma _{3^{\prime \prime }}$| are in general tightly correlated, the log  M ∗ − log  SK relation has less scatter than the |$\log M_* - \log \sigma _{3^{\prime \prime }}$| relation. [ABSTRACT FROM AUTHOR]

We present the extended GALEX Arecibo SDSS Survey (xGASS), a gas fraction-limited census of the atomic hydrogen (H I) gas content of 1179 galaxies selected only by stellar mass (M* = 109-1011.5 M⊙) and redshift (0.01

The fraction of galaxies supported by internal rotation compared to galaxies stabilized by internal pressure provides a strong constraint on galaxy formation models. In integral field spectroscopy surveys, this fraction is biased because survey instruments typically only trace the inner parts of the most massive galaxies. We present aperture corrections for the two most widely used stellar kinematic quantities V/σ and λR (spin parameter proxy). Our demonstration involves integral field data from the SAMI (Sydney-AAO Multi-object Integral-field spectrograph) Galaxy Survey and the ATLAS3D survey. We find a tight relation for both V/σ and λR when measured in different apertures that can be used as a linear transformation as a function of radius, i.e. a first-order aperture correction. In degraded seeing, however, the aperture corrections are more significant as the steeper inner profile is more strongly affected by the point spread function than the outskirts. We find that V/σ and λR radial growth curves are well approximated by second-order polynomials. By only fitting the inner profile (0.5Re), we successfully recover the profile out to one Re if a constraint between the linear and quadratic parameter in the fit is applied. However, the aperture corrections for V/σ and λR derived by extrapolating the profiles perform as well as applying a first-order correction. With our aperture-corrected λR measurements, we find that the fraction of slow rotating galaxies increases with stellar mass. For galaxies with logM*/M☉ > 11, the fraction of slow rotators is 35.9 ± 4.3 per cent, but is underestimated if galaxies without coverage beyond one Re are not included in the sample (24.2 ± 5.3 per cent). With measurements out to the largest aperture radius, the slow rotator fraction is similar as compared to using aperture-corrected values (38.3 ± 4.4 per cent). Thus, aperture effects can significantly bias stellar kinematic integral field spectrograph studies, but this bias can now be removed with the method outlined here. [ABSTRACT FROM AUTHOR]

We present an analysis of the global stellar populations of galaxies in the SAMI (Sydney- AAO Multi-object Integral field spectrograph) Galaxy Survey. Our sample consists of 1319 galaxies spanning four orders of magnitude in stellar mass and includes all morphologies and environments. We derive luminosity-weighted, single stellar population equivalent stellar ages, metallicities and alpha enhancements from spectra integrated within one effective radius apertures. Variations in galaxy size explain the majority of the scatter in the age-mass and metallicity-mass relations. Stellar populations vary systematically in the plane of galaxy size and stellar mass, such that galaxies with high stellar surface mass density are older, more metal rich and alpha enhanced than less dense galaxies. Galaxies with high surface mass densities have a very narrow range of metallicities; however, at fixed mass, the spread in metallicity increases substantially with increasing galaxy size (decreasing density). We identify residual correlations with morphology and environment. At fixed mass and size, galaxies with late-type morphologies, small bulges and low Sérsic n are younger than early type, high n, high bulgeto- total galaxies. Both age and metallicity show small residual correlations with environment; at fixed mass and size, galaxies in denser environments or more massive haloes are older and somewhat more metal rich than those in less dense environments. We connect these trends to evolutionary tracks within the size-mass plane. [ABSTRACT FROM AUTHOR]

Nowadays, the total hip arthroplasty (THA) is a widespread surgical procedure, representing the best option to restore hip joint mobility in patients suffering from trauma or joint diseases. One of the well-known possible drawbacks of THA is the stress-shielding phenomenon. Some years after the surgery, the femur starts to degrade because of its persistent unloaded condition induced by the high prosthesis stiffness, which carries the great part of the load normally taken by the bone. This condition is particularly invalidating in younger patients, with longer life expectation after the operation, requiring one or multiple additional operations to restore the proper prosthesis-bone firm connection. The present study tries to address this issue proposing an innovative prosthesis design, taking advantage of the shape freedom ensured by Additive Manufacturing techniques. Additionally, the structural integrity of the novel prosthesis is assessed using a ductile damage numerical approach. Different prosthesis geometries were investigated: one conventional and commercially available already, and two more innovative geometries. For each one, a bulk solution was compared to a lighter version characterized by an inner reticular structure with a body-centred cubic unit cell and by an equivalent density of about 5%, only feasible through the additive manufacturing fabrication. Extensive Finite Element numerical simulations were carried out to compare the percentage of the induced stress shielding for the different prosthesis geometries. Pros and cons of each geometry were pointed out and eventually the most promising solution in limiting the stress shielding phenomenon was chosen. At the same time, the structural integrity of the selected design was ensured, embedding a ductile damage model in the Finite Element analysis, calibrated on a SLM Ti6Al4V, the biocompatible alloy for the prosthesis fabrication. Structural safety was evaluated under four different loading conditions: walking, stumbling, the exceptional overload due to hammering insertion during surgery and the force which induced the collapse of the implant. Additionally, the safety margin was quantified through the definition of an overall safety factor under the maximum expected load. • Hip prosthesis design based on additive manufacturing technology. • Reduction of prosthesis stiffness using a lattice core to mitigate stress shielding. • Numerical structural assessment of the prosthesis under unconventional load cases. • Prediction of failure load of the prosthesis by means of a ductile damage model. [ABSTRACT FROM AUTHOR]