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Schwarzschild dynamical models are now regularly employed in large surveys of galaxies in the local and distant Universe to derive information on galaxies' intrinsic properties such as their orbital structure and their (dark matter and stellar) mass distribution. Comparing the internal orbital structures and mass distributions of galaxies in the distant Universe with simulations is key to understanding what physical processes are responsible for shaping galaxy properties. However it is first crucial to understand whether observationally derived properties are directly comparable with intrinsic ones in simulations. To assess this, we build Schwarzschild dynamical models for MUSE-like IFS cubes (constructed to be like those obtained by the MAGPI survey) of 75 galaxies at z ~ 0.3 from the Eagle simulations. We compare the true particle-derived properties with the galaxies' model-derived properties. In general, we find that the models can recover the true galaxy properties qualitatively well, with the exception of the enclosed dark matter, where we find a median offset of 48%, which is due to the assumed NFW profile not being able to reproduce the dark matter distribution in the inner region of the galaxies. We then compare our model-derived properties with Schwarzschild models-derived properties of observed MAGPI galaxies and find good agreement between MAGPI and Eagle: the majority of our galaxies (57%) have non-oblate shapes within 1 effective radius. More triaxial galaxies show higher fractions of hot orbits in their inner regions and tend to be more radially anisotropic., Comment: 22 pages. Accepted for publication in MNRAS

Milky Way Analogues (MWAs) provide an alternative insight into the various pathways that lead to the formation of disk galaxies with similar properties to the Milky Way. In this study, we explore different selection techniques for identifying MWAs in the SAMI Galaxy Survey. We utilise a nearest neighbours method to define MWAs using four selection parameters including stellar mass ($M_{\star}$), star formation rate ($SFR$), bulge-to-total ratio ($B/T$) and disk effective radius ($R_{\rm{e}}$). Based on 15 different selection combinations, we find that including $M_{\star}$ and SFR is essential for minimising biases in the average MWA properties as compared to the Milky Way. Furthermore, given the Milky Way's smaller-than-average size, selection combinations without $R_{\rm{e}}$ result in MWAs being too large. Lastly, we find that $B/T$ is the least important parameter out of the four tested parameters. Using all four selection criteria, we define the top 10 most Milky Way-like galaxies in the GAMA and Cluster regions of the SAMI survey. These most Milky-Way-like galaxies are typically barred spirals, with kinematically cold rotating disks and reside in a wide range of environments. Surprisingly, we find no significant differences between the MWAs selected from the GAMA and Cluster regions. Our work highlights the importance of using multiple selection criteria for finding MWAs and also demonstrates potential biases in previous MWA studies., Comment: 26 pages, 16 figures, 5 tables, accepted for publication in MNRAS

While quiescent galaxies have comparable amounts of cool gas in their outer circumgalactic medium (CGM) compared to star-forming galaxies, they have significantly less interstellar gas. However, open questions remain on the processes causing galaxies to stop forming stars and stay quiescent . Theories suggest dynamical interactions with the hot corona prevent cool gas from reaching the galaxy, therefore predicting the inner regions of quiescent galaxy CGMs are devoid of cool gas. However, there is a lack of understanding of the inner regions of CGMs due to the lack of spatial information in quasar-sightline methods. We present integral-field spectroscopy probing 10--20~kpc (2.4--4.8 R\textsubscript{e}) around a massive quiescent galaxy using a gravitationally lensed star-forming galaxy. We detect absorption from Magnesium (MgII) implying large amounts of cool atomic gas (10\textsuperscript{8.4} -- 10\textsuperscript{9.3} M\textsubscript{$\odot$} with T$\sim$10\textsuperscript{4} Kelvin), in comparable amounts to star-forming galaxies. Lens modeling of Hubble imaging also reveals a diffuse asymmetric component of significant mass consistent with the spatial extent of the MgII absorption, and offset from the galaxy light profile. This study demonstrates the power of galaxy-scale gravitational lenses to not only probe the gas around galaxies, but to also independently probe the mass of the CGM due to it's gravitational effect., Comment: accepted nature communications physics

We use deep spectroscopy from the SAMI Galaxy Survey to explore the precision of the fundamental plane of early-type galaxies (FP) as a distance indicator for future single-fibre spectroscopy surveys. We study the optimal trade-off between sample size and signal-to-noise ratio (SNR), and investigate which additional observables can be used to construct hyperplanes with smaller intrinsic scatter than the FP. We add increasing levels of random noise (parametrised as effective exposure time) to the SAMI spectra to study the effect of increasing measurement uncertainties on the FP-and hyperplane-inferred distances. We find that, using direct-fit methods, the values of the FP and hyperplane best-fit coefficients depend on the spectral SNR, and reach asymptotic values for a mean SNR=40 {\AA}$^{-1}$. As additional variables for the FP we consider three stellar-population observables: light-weighted age, stellar mass-to-light ratio and a novel combination of Lick indices (I$_{\rm age}$). For a SNR=45 {\AA}$^{-1}$ (equivalent to 1-hour exposure on a 4-m telescope), all three hyperplanes outperform the FP as distance indicators. Being an empirical spectral index, I$_{\rm age}$ avoids the model-dependent uncertainties and bias underlying age and mass-to-light ratio measurements, yet yields a 10 per cent reduction of the median distance uncertainty compared to the FP. We also find that, as a by-product, the Iage hyperplane removes most of the reported environment bias of the FP. After accounting for the different signal-to-noise ratio, these conclusions also apply to a 50 times larger sample from SDSS-III. However, in this case, only age removes the environment bias., Comment: 24 pages, 18 figures, accepted for publication in MNRAS

BlueMUSE is a blue-optimised, medium spectral resolution, panoramic integral field spectrograph under development for the Very Large Telescope (VLT). With an optimised transmission down to 350 nm, spectral resolution of R$\sim$3500 on average across the wavelength range, and a large FoV (1 arcmin$^2$), BlueMUSE will open up a new range of galactic and extragalactic science cases facilitated by its specific capabilities. The BlueMUSE consortium includes 9 institutes located in 7 countries and is led by the Centre de Recherche Astrophysique de Lyon (CRAL). The BlueMUSE project development is currently in Phase A, with an expected first light at the VLT in 2031. We introduce here the Top Level Requirements (TLRs) derived from the main science cases, and then present an overview of the BlueMUSE system and its subsystems fulfilling these TLRs. We specifically emphasize the tradeoffs that are made and the key distinctions compared to the MUSE instrument, upon which the system architecture is built., Comment: 20 pages, 10 figures, proceedings of the SPIE astronomical telescopes and instrumentation conference, Yokohama, 16-21 June

We use the `Middle Ages Galaxy Properties with Integral field spectroscopy' (MAGPI) survey to investigate whether galaxies have evolved in the distribution of their stellar angular momentum in the past 3-4 Gyr, as probed by the observational proxy for spin, $\lambda_{R}$. We use 2D stellar kinematics to measure $\lambda_{R}$ along with detailed photometric models to estimate galaxy ellipticity. The combination of these measurements quantifies the kinematic classes of `fast rotators' and the rarer `slow rotators', which show no regular rotation in their line-of-sight velocity fields. We compare 51 MAGPI galaxies with $\log_{10} (M_{\star}/\mathrm{M}_\odot) > 10$ to carefully drawn samples of MaNGA galaxies in the local Universe, selected to represent possible descendants of the MAGPI progenitors. The EAGLE simulations are used to identify possible evolutionary pathways between the two samples, explicitly accounting for progenitor bias in our results and the varied evolutionary pathways a galaxy might take between the two epochs. We find that the occurrence of slow rotating galaxies is unchanged between the MAGPI ($z \sim 0.3$) and MaNGA ($z \sim 0$) samples, suggesting the massive slow rotator population was already in place $\sim 4$ Gyr ago and has not accumulated since. There is a hint of the MAGPI sample having an excess of high $\lambda_{R}$ galaxies compared to the MaNGA sample, corresponding to more ordered rotation, but statistically the samples are not significantly different. The large-scale stellar kinematics, as quantified through the $\lambda_{R}$ parameter, of galaxies at $z \sim 0.3$ have already evolved into the diversity of structures seen today in the local Universe., Comment: 10 pages, 7 figures, accepted for publication in MNRAS

We investigate the influence of star formation and instantaneous AGN feedback processes on the ionized gas velocity dispersion in a sample of 1285 emission-line galaxies with stellar masses $\log\,(M_*/M_{\odot}) \geq 9$ from the integral-field spectroscopy SAMI Galaxy Survey. We fit both narrow and broad emission line components using aperture spectra integrated within one effective radius, while ensuring the elimination of velocity differences between the spectra of individual spaxels. Our analysis reveals that 386 (30%) galaxies can be adequately described using a single emission component while 356 (28%) galaxies require two (broad and narrow) components. Galaxies characterized by high mass, elevated star formation rate surface density, or type-2 AGN-like emissions tend to feature an additional broad emission-line component, leading to their classification as double-component galaxies. We explore the correlations between $M_*$ and gas velocity dispersions, highlighting that the prominence of the broad component significantly contributes to elevating the gas velocity dispersion. Galaxies displaying AGN-like emission based on optical definitions show enhanced gas velocity dispersions. In star-forming galaxies, both stellar mass and star-formation rate surface density substantially contribute to the velocity dispersion of the narrow component. Increased star-forming activity appears to elevate the velocity dispersion of the narrow component. The broad component exhibits a weaker dependence on stellar mass and is primarily driven by galactic outflows. We suggest that strong star forming activity leads to the formation of a broad emission-line component, but the impact on inflating gas velocity dispersion is moderate. On the other hand, AGN-driven outflows appear to be a more important contributor to the elevated velocity dispersion of the ionized gas., Comment: 17 pages, 11 figures

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 program 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 $\sim6\,$kpc bipolar outflow fuelled by one of Virgo's most HI-rich discs. The spectacular MUSE data reveal the clumpy structure and complex kinematics of the ionised gas in this M82-like outflow at 100 pc resolution. Using the ionised gas geometry and kinematics we constrain the opening half-angle to $\theta=25-35^\circ$, while the average outflow velocity is $\sim210$ kms$^{-1}$. The emission line ratios reveal an ionisation structure where photoionisation is the dominant excitation process. The outflowing gas shows a marginally elevated gas-phase oxygen abundance compared to the disc but is 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 $\sim1.8~$M$_\odot$yr$^{-1}$ and a corresponding mass-loading factor in the range 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., Comment: 16 pages, 7 figures, 1 appendix. Accepted to MNRAS

Slow rotator galaxies are distinct amongst galaxy populations, with simulations suggesting that a mix of minor and major mergers are responsible for their formation. A promising path to resolve outstanding questions on the type of merger responsible, is by investigating deep imaging of massive galaxies for signs of potential merger remnants. We utilise deep imaging from the Subaru-Hyper Suprime Cam Wide data to search for tidal features in massive ($\log_{10}(M_*/M_{\odot}) > 10$) early-type galaxies (ETGs) in the SAMI Galaxy Survey. We perform a visual check for tidal features on images where the galaxy has been subtracted using a Multi-Gauss Expansion (MGE) model. We find that $31\pm 2$ percent of our sample show tidal features. When comparing galaxies with and without features, we find that the distributions in stellar mass, light-weighted mean stellar population age and H$\alpha$ equivalent width are significantly different, whereas spin ($\lambda_{R_e}$), ellipticity and bulge to total ratio have similar distributions. When splitting our sample in age, we find that galaxies below the median age (10.8 Gyr) show a correlation between the presence of shells and lower $\lambda_{R_e}$, as expected from simulations. We also find these younger galaxies which are classified as having "strong" shells have lower $\lambda_{R_e}$. However, simulations suggest that merger features become undetectable within $\sim 2-4$ Gyr post-merger. This implies that the relationship between tidal features and merger history disappears for galaxies with older stellar ages, i.e. those that are more likely to have merged long ago., Comment: Accepted for publication in MNRAS. 22 pages, 14 figures

We use the SAMI galaxy survey to study the the kinematic morphology-density relation: the observation that the fraction of slow rotator galaxies increases towards dense environments. We build a logistic regression model to quantitatively study the dependence of kinematic morphology (whether a galaxy is a fast rotator or slow rotator) on a wide range of parameters, without resorting to binning the data. Our model uses a combination of stellar mass, star-formation rate (SFR), $r$-band half-light radius and a binary variable based on whether the galaxy's observed ellipticity ($\epsilon$) is less than 0.4. We show that, at fixed mass, size, SFR and $\epsilon$, a galaxy's local environmental surface density ($\log_{10}(\Sigma_5/\mathrm{Mpc}^{-2})$) gives no further information about whether a galaxy is a slow rotator, i.e. the observed kinematic-morphology density relation can be entirely explained by the well-known correlations between environment and other quantities. We show how our model can be applied to different galaxy surveys to predict the fraction of slow rotators which would be observed and discuss its implications for the formation pathways of slow rotators., Comment: 12 pages, 6 figures. Accepted for publication in MNRAS

Galactic fountains driven by star formation result in a variety of kinematic structures such as ionised winds and thick gas disks, both of which manifest as complex emission line profiles that can be parametrised by multiple Gaussian components. We use integral field spectroscopy (IFS) from the SAMI Galaxy Survey to spectrally resolve these features, traced by broad H$\alpha$ components, and distinguish them from the star-forming thin disk, traced by narrow components, in 3068 galaxies in the local Universe. Using a matched sample analysis technique, we demonstrate that the presence of complex emission line profiles in star-forming galaxies is most strongly correlated with the global star formation rate (SFR) surface density of the host galaxy measured within $1R_{\rm e}$ ($\Sigma_{{\rm SFR},R_{\rm e}}$), even when controlling for both observational biases, including inclination, amplitude-to-noise and angular scale, and sample biases in parameters such as stellar mass and SFR. Leveraging the spatially resolved nature of the dataset, we determine that the presence of complex emission line profiles within individual spaxels is driven not only by the local $\Sigma_{\rm SFR}$, but by the $\Sigma_{{\rm SFR},R_{\rm e}}$ of the host galaxy. We also parametrise the clumpiness of the SFR within individual galaxies, and find that $\Sigma_{{\rm SFR},R_{\rm e}}$ is a stronger predictor of the presence of complex emission line profiles than clumpiness. We conclude that, with a careful treatment of observational effects, it is possible to identify structures traced by complex emission line profiles, including winds and thick ionised gas disks, at the spatial and spectral resolution of SAMI using the Gaussian decomposition technique., Comment: 21 pages, 17 figures, accepted for publication in MNRAS

The stellar mass Tully-Fisher relation (STFR) and its scatter encode valuable information about the processes shaping galaxy evolution across cosmic time. However, we are still missing a proper quantification of the STFR slope and scatter dependence on the baryonic tracer used to quantify rotational velocity, on the velocity measurement radius and on galaxy integrated properties. We present a catalogue of stellar and ionised gas (traced by H$\alpha$ emission) kinematic measurements for a sample of galaxies drawn from the MaNGA Galaxy Survey, providing an ideal tool for galaxy formation model calibration and for comparison with high-redshift studies. We compute the STFRs for stellar and gas rotation at 1, 1.3 and 2 effective radii ($R_e$). The relations for both baryonic components become shallower at 2$R_e$ compared to 1$R_e$ and 1.3$R_e$. We report a steeper STFR for the stars in the inner parts ($\leq 1.3 R_e$) compared to the gas. At 2$R_e$, the relations for the two components are consistent. When accounting for covariances with integrated v/$\sigma$, scatter in the stellar and gas STFRs shows no strong correlation with: optical morphology, star formation rate surface density, tidal interaction strength or gas accretion signatures. Our results suggest that the STFR scatter is driven by an increase in stellar/gas dispersional support, from either external (mergers) or internal (feedback) processes. No correlation between STFR scatter and environment is found. Nearby Universe galaxies have their stars and gas in statistically different states of dynamical equilibrium in the inner parts ($\leq 1.3 R_e$), while at 2$R_{e}$ the two components are dynamically coupled., Comment: 21 pages, 12 figures. Accepted for publication in MNRAS

Ongoing deep IFS observations of disk galaxies provide opportunities for comparison with the Milky Way (MW) to understand galaxy evolution. However, such comparisons are marred by many challenges such as selection effects, differences in observations and methodology, and proper validation of full-spectrum fitting methods. In this study, we present a novel code GalCraft to address these challenges by generating mock IFS data cubes of the MW using simple stellar population models and a mock MW stellar catalog derived from E-Galaxia. We use the widely adopted full-spectrum fitting code pPXF to investigate the ability to recover kinematics and stellar populations for an edge-on mock MW IFS observation. We confirm that differences in kinematics, mean age, [M/H], and [$\alpha$/Fe] between thin and thick disks can be distinguished. However, the age distribution is overestimated in the ranges between 2 - 4 and 12 - 14 Gyr compared to the expected values. This is likely due to the age spacing and degeneracy of SSP templates. We find systematic offsets in the recovered kinematics due to insufficient spectral resolution and the variation of line-of-sight velocity distribution with age and [M/H]. With future higher resolution and multi-[$\alpha$/Fe] SSP templates, GalCraft will be useful to validate key signatures such as [$\alpha$/Fe]-[M/H] distribution at different $R$ and $|z|$ and potentially infer radial migration and kinematic heating efficiency to study detailed chemodynamical evolution of MW-like galaxies., Comment: 30 pages, 30 figures, accepted by MNRAS. GalCraft available via https://github.com/purmortal/galcraft

The activity of central supermassive black holes might affect the alignment of galaxy spin axes with respect to the closest cosmic filaments. We exploit the SAMI Galaxy Survey to study possible relations between black hole activity and the spin-filament alignments of stars and ionised gas separately. To explore the impact of instantaneous black hole activity, active galaxies are selected according to emission-line diagnostics. Central stellar velocity dispersion ($\sigma_c$) is used as a proxy for black hole mass and its integrated activity. We find evidence for the gas spin-filament alignments to be influenced by AGN, with Seyfert galaxies showing a stronger perpendicular alignment at fixed bulge mass with respect to galaxies where ionisation is consequence of low-ionizaition nuclear emission-line regions (LINERs) or old stellar populations (retired galaxies). On the other hand, the greater perpendicular tendency for the stellar spin-filament alignments of high-bulge mass galaxies is dominated by retired galaxies. Stellar alignments show a stronger correlation with $\sigma_c$ compared to the gas alignments. We confirm that bulge mass ($M_{bulge}$) is the primary parameter of correlation for both stellar and gas spin-filament alignments (with no residual dependency left for $\sigma_c$), while $\sigma_c$ is the most important property for secular star formation quenching (with no residual dependency left for $M_{bulge}$). These findings indicate that $M_{bulge}$ and $\sigma_c$ are the most predictive parameters of two different galaxy evolution processes, suggesting mergers trigger spin-filament alignment flips and integrated black hole activity drives star formation quenching., Comment: 20 pages, 16 figures, accepted for publication in MNRAS

Current methods of identifying the ionizing source of nebular emission in galaxies are well defined for the era of single fiber spectroscopy, but still struggle to differentiate the complex and overlapping ionization sources in some galaxies. With the advent of integral field spectroscopy, the limits of these previous classification schemes are more apparent. We propose a new method for distinguishing the ionizing source in resolved galaxy spectra by use of a multi-dimensional diagnostic diagram that compares emission line ratios with velocity dispersion on a spaxel by spaxel basis within a galaxy. This new method is tested using the SAMI Galaxy Survey Data Release 3, which contains 3068 galaxies at z $<$ 0.12. Our results are released as ionization maps available alongside the SAMI DR3 public data. Our method accounts for a more diverse range of ionization sources than the standard suite of emission line diagnostics; we find 1433 galaxies with significant contribution from non-star-forming ionization using our improved method as compared to 316 galaxies identified using only emission line ratio diagnostics. Within these galaxies, we further identify 886 galaxies hosting unique signatures inconsistent with standard ionization by H2 regions, AGN, or shocks. These galaxies span a wide range of masses and morphological types and comprise a sizable portion of the galaxies used in our sample. With our revised method, we show that emission line diagnostics alone do not adequately differentiate the multiple ways to ionize gas within a galaxy.

We present the first study of spatially integrated higher-order stellar kinematics over cosmic time. We use deep rest-frame optical spectroscopy of quiescent galaxies 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 parametrised as a Gauss-Hermite series. Conservatively using a redshift-independent cut in stellar mass ($M_\star = 10^{11}\,{\rm M}_\odot$), and matching the stellar-mass distributions of our samples, we find 7 $\sigma$ evidence of $h_4$ increasing with cosmic time, from a median value of 0.019$\pm$0.002 at z=0.8 to 0.059$\pm$0.004 at z=0.06. Alternatively, we use a physically motivated sample selection, based on the mass distribution of the progenitors of local quiescent galaxies as inferred from numerical simulations; in this case, we find 10 $\sigma$ evidence. This evolution suggests that, over the last 7 Gyr, there has been a gradual decrease in the rotation-to-dispersion ratio and an increase in the radial anisotropy of the stellar velocity distribution, qualitatively consistent with accretion of gas-poor satellites. These findings demonstrate that massive galaxies continue to accrete mass and increase their dispersion support after becoming quiescent., Comment: 19 pages, 9 figures Accepted for publication in MNRAS

Most dynamical models of galaxies to date assume axisymmetry, which is not representative of a significant fraction of massive galaxies. We have built triaxial orbit-superposition Schwarzschild models of galaxies observed by the SAMI Galaxy Survey, in order to reconstruct their inner orbital structure and mass distribution. The sample consists of 153 passive galaxies with total stellar masses in the range $10^{9.5}$ to $10^{12} M_{\odot}$. We present an analysis of the internal structures and intrinsic properties of these galaxies as a function of their environment. We measure their environment using three proxies: central or satellite designation, halo mass and local $5^{th}$ nearest neighbour galaxy density. We find that although these intrinsic properties correlate most strongly with stellar mass, environment does play a secondary role: at fixed stellar mass, galaxies in the densest regions are more radially anisotropic. In addition, central galaxies, and galaxies in high local densities show lower values of edge-on spin parameter proxy \lam. We also find suggestions of a possible trend of the fractions of orbits with environment for lower-mass galaxies (between $10^{9.5}$ and $10^{11} M_{\odot}$) such that, at fixed stellar mass, galaxies in higher local densities and halo mass have higher fractions of hot orbits and lower fractions of warm orbits. Our results demonstrate that after stellar mass, environment does play a role in shaping present-day passive galaxies., Comment: 21 pages. Accepted for publication in MNRAS

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 $M_\star > 10^{10.5} {\rm M}_\odot$) 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 parametrised as a Gauss-Hermite series. We find that at all redshifts where we have large enough samples, $h_4$ anti-correlates with the ratio between rotation and dispersion, highlighting the physical connection between these two kinematic observables. In addition, and independently from the anti-correlation with rotation-to-dispersion ratio, we also find a correlation between $h_4$ and $M_\star$, 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., Comment: 26 pages, 15 figures Accepted for publication in MNRAS

We study environmental quenching in the Eagle}/C-Eagle cosmological hydrodynamic simulations over the last 11 Gyr (i.e. $z=0-2$). The simulations are compared with observations from the SAMI Galaxy Survey at $z=0$. We focus on satellite galaxies in galaxy groups and clusters ($10^{12}\,\rm M_{\odot}$ $\lesssim$ $M_{200}$ < $3 \times 10^{15}\, \rm M_{\odot}$). A star-formation concentration index [$C$-index $= \log_{10}(r_\mathrm{50,SFR} / r_\mathrm{50,rband})$] is defined, which measures how concentrated star formation is relative to the stellar distribution. Both Eagle/C-Eagle and SAMI show a higher fraction of galaxies with low $C$-index in denser environments at $z=0-0.5$. Low $C$-index galaxies are found below the SFR-$M_{\star}$ main sequence (MS), and display a declining specific star formation rate (sSFR) with increasing radii, consistent with ``outside-in'' environmental quenching. Additionally, we show that $C$-index can be used as a proxy for how long galaxies have been satellites. These trends become weaker at increasing redshift and are absent by $z=1-2$. We define a quenching timescale $t_{\rm quench}$ as how long it takes satellites to transition from the MS to the quenched population. We find that simulated galaxies experiencing ``outside-in'' environmental quenching at low redshift ($z=0\sim0.5$) have a long quenching timescale (median $t_{\rm quench}$ > 2 Gyr). The simulated galaxies at higher redshift ($z=0.7\sim2$) experience faster quenching (median $t_{\rm quench}$ < 2Gyr). At $z\gtrsim 1-2$ galaxies undergoing environmental quenching have decreased sSFR across the entire galaxy with no ``outside-in'' quenching signatures and a narrow range of $C$-index, showing that on average environmental quenching acts differently than at $z\lesssim 1$., Comment: 21 pages, 17 figures

We explore local and global dynamical differences between the kinematics of ionised gas and stars in a sample of galaxies from Data Release 3 of the SAMI Galaxy Survey. We find better agreement between local (i.e., comparing on a spaxel-to-spaxel basis) velocities and dispersion of gas and stars in younger systems as with previous work on the asymmetric drift in galaxies, suggesting that the dynamics of stars and ionised gas are initially coupled. The intrinsic scatter around the velocity and dispersion relations increases with increasing stellar age and mass, suggesting that subsequent mechanisms such as internal processes, divergent star formation and assembly histories also play a role in setting and altering the dynamics of galaxies. The global (flux-weighted) dynamical support of older galaxies is hotter than in younger systems. We find that the ionised gas in galaxies is almost always dynamically colder than the stars with a steeper velocity gradient. In absolute terms, the local difference in velocity dispersion is more pronounced than the local difference in velocity, possibly reflecting inherent differences in the impact of turbulence, inflow and/or feedback on gas compared to stars. We suggest how these findings may be taken into account when comparing high and low redshift galaxy samples to infer dynamical evolution., Comment: 11 pages, 9 figures, 1 table, accepted for publication in MNRAS

We present SAMI-HI, a survey of the atomic hydrogen content of 296 galaxies with integral field spectroscopy available from the SAMI Galaxy Survey. The sample spans nearly 4 dex in stellar mass ($M_\star = 10^{7.4}-10^{11.1}~ \rm M_\odot$), redshift $z<0.06$, and includes new Arecibo observations of 153 galaxies, for which we release catalogues and HI spectra. We use these data to compare the rotational velocities obtained from optical and radio observations and to show how systematic differences affect the slope and scatter of the stellar-mass and baryonic Tully-Fisher relations. Specifically, we show that H$\alpha$ rotational velocities measured in the inner parts of galaxies (1.3 effective radii in this work) systematically underestimate HI global measurements, with HI/H$\alpha$ velocity ratios that increase at low stellar masses, where rotation curves are typically still rising and H$\alpha$ measurements do not reach their plateau. As a result, the H$\alpha$ stellar mass Tully-Fisher relation is steeper (when $M_\star$ is the independent variable) and has larger scatter than its HI counterpart. Interestingly, we confirm the presence of a small fraction of low-mass outliers of the H$\alpha$ relation that are not present when HI velocity widths are used and are not explained by "aperture effects". These appear to be highly disturbed systems for which H$\alpha$ widths do not provide a reliable estimate of the rotational velocity. Our analysis reaffirms the importance of taking into account differences in velocity definitions as well as tracers used when interpreting offsets from the Tully-Fisher relation, at both low and high redshifts and when comparing with simulations., Comment: 18 pages, 12 figures. Accepted for publication in MNRAS

Observations of the neutral atomic hydrogen (HI) gas in galaxies are predominantly spatially unresolved, in the form of a global HI spectral line. There has been substantial work on quantifying asymmetry in global HI spectra (`global HI asymmetry'), but due to being spatially unresolved, it remains unknown what physical regions of galaxies the asymmetry traces, and whether the other gas phases are affected. Using optical integral field spectrograph (IFS) observations from the Sydney AAO Multi-object IFS (SAMI) survey for which global HI spectra are also available (SAMI-HI), we study the connection between asymmetry in galaxies' ionised and neutral gas reservoirs to test if and how they can help us better understand the origin of global HI asymmetry. We reconstruct the global H$\alpha$ spectral line from the IFS observations and find that, while some global H$\alpha$ asymmetries can arise from disturbed ionised gas kinematics, the majority of asymmetric cases are driven by the distribution of H$\alpha$-emitting gas. When compared to the HI, we find no evidence for a relationship between the global H$\alpha$ and HI asymmetry. Further, a visual inspection reveals that cases where galaxies have qualitatively similar H$\alpha$ and HI spectral profiles can be spurious, with the similarity originating from an irregular 2D H$\alpha$ flux distribution. Our results highlight that comparisons between global H$\alpha$ and HI asymmetry are not straightforward, and that many global HI asymmetries trace disturbances that do not significantly impact the central regions of galaxies., Comment: 11 pages, 6 figures, 1 appendix, accepted for publication in MNRAS

We study environmental quenching using the spatial distribution of current star-formation and stellar population ages with the full SAMI Galaxy Survey. By using a star-formation concentration index [C-index, defined as log10(r_{50,Halpha}/r_{50,cont})], we separate our sample into regular galaxies (C-index>-0.2) and galaxies with centrally concentrated star-formation (SF-concentrated; C-index<-0.2). Concentrated star-formation is a potential indicator of galaxies currently undergoing `outside-in' quenching. Our environments cover ungrouped galaxies, low-mass groups (M_200<10^12.5 M_sun), high-mass groups (M_200 in the range 10^{12.5-14} M_sun) and clusters (M_200>10^14 M_sun). We find the fraction of SF-concentrated galaxies increases as halo mass increases with 9\pm2 per cent, 8\pm3 per cent, 19\pm4 per cent and 29\pm4 per cent for ungrouped galaxies, low-mass groups, high-mass groups and clusters, respectively. We interpret these results as evidence for `outside-in' quenching in groups and clusters. To investigate the quenching time-scale in SF-concentrated galaxies, we calculate light-weighted age (Age_L) and mass-weighted age (Age_M) using full spectral fitting, as well as the Dn4000 and Hdelta_A indices. We assume that the average galaxy age radial profile before entering a group or cluster is similar to ungrouped regular galaxies. At large radius (1-2 R_e), SF-concentrated galaxies in high-mass groups have older ages than ungrouped regular galaxies with an age difference of 1.83\pm0.38 Gyr for Age_L and 1.34\pm0.56 Gyr for Age_M. This suggests that while `outside-in' quenching can be effective in groups, the process will not quickly quench the entire galaxy. In contrast, the ages at 1-2 R_e of cluster SF-concentrated galaxies and ungrouped regular galaxies are consistent (0.19\pm0.21 Gyr for Age_L, 0.40\pm0.61 Gyr for Age_M), suggesting the quenching process must be rapid., Comment: 20 pages, 18 figures

We study the alignments of galaxy spin axes with respect to cosmic web filaments as a function of various properties of the galaxies and their constituent bulges and discs. We exploit the SAMI Galaxy Survey to identify 3D spin axes from spatially-resolved stellar kinematics and to decompose the galaxy into the kinematic bulge and disc components. The GAMA survey is used to reconstruct the cosmic filaments. The mass of the bulge, defined as the product of stellar mass and bulge-to-total flux ratio M_bulge=M_star x (B/T), is the primary parameter of correlation with spin-filament alignments: galaxies with lower bulge masses tend to have their spins parallel to the closest filament, while galaxies with higher bulge masses are more perpendicularly aligned. M_star and B/T separately show correlations, but they do not fully unravel spin-filament alignments. Other galaxy properties, such as visual morphology, stellar age, star formation activity, kinematic parameters and local environment, are secondary tracers. Focusing on S0 galaxies, we find preferentially perpendicular alignments, with the signal dominated by high-mass S0 galaxies. Studying bulge and disc spin-filament alignments separately reveals additional information about the formation pathways of the corresponding galaxies: bulges tend to have more perpendicular alignments, while discs show different tendencies according to their kinematic features and the mass of the associated bulge. The observed correlation between the flipping of spin-filament alignments and the growth of the bulge can be explained by mergers, which drive both alignment flips and bulge formation., Comment: Accepted for publication in MNRAS. 23 pages, 22 figures, 2 3D models at https://skfb.ly/o9MXv and https://skfb.ly/o9MXz, 5 supplementary figures

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, $\Phi$ = log10(M/M*) - log10($r_e$/kpc). 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 $\Phi$, and show that the offset in [Z/H] between passive and star-forming galaxies at fixed $\Phi$ is smaller than or equal to the offset in [Z/H] at fixed mass (an average $\Delta$[Z/H] of 0.11 dex at fixed $\Phi$ 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 $\Phi$ 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., Comment: 18 pages, 15 figures. Accepted for publication in MNRAS

Using data from the SAMI Galaxy Survey, we investigate the correlation between the projected stellar kinematic spin vector of 1397 SAMI galaxies and the line-of-sight motion of their neighbouring galaxies. We calculate the luminosity-weighted mean velocity difference between SAMI galaxies and their neighbours in the direction perpendicular to the SAMI galaxies angular momentum axes. The luminosity-weighted mean velocity offsets between SAMI and neighbours, which indicates the signal of coherence between the rotation of the SAMI galaxies and the motion of neighbours, is 9.0 $\pm$ 5.4 km s$^{-1}$ (1.7 $\sigma$) for neighbours within 1 Mpc. In a large-scale analysis, we find that the average velocity offsets increase for neighbours out to 2 Mpc. However, the velocities are consistent with zero or negative for neighbours outside 3 Mpc. The negative signals for neighbours at distance around 10 Mpc are also significant at $\sim 2$ $\sigma$ level, which indicate that the positive signals within 2 Mpc might come from the variance of large-scale structure. We also calculate average velocities of different subsamples, including galaxies in different regions of the sky, galaxies with different stellar masses, galaxy type, $\lambda_{Re}$ and inclination. Although low-mass, high-mass, early-type and low-spin galaxies subsamples show 2 - 3 $\sigma$ signal of coherence for the neighbours within 2 Mpc, the results for different inclination subsamples and large-scale results suggest that the $\sim 2 \sigma$ signals might result from coincidental scatter or variance of large-scale structure. Overall, the modest evidence of coherence signals for neighbouring galaxies within 2 Mpc needs to be confirmed by larger samples of observations and simulation studies., Comment: 14 pages, 9 figures, accepted for publication in MNRAS

We explore a sample of 1492 galaxies with measurements of the mean stellar population properties and the spin parameter proxy, $\lambda_{R_{\rm{e}}}$, drawn from the SAMI Galaxy Survey. We fit a global $\left[\alpha/\rm{Fe}\right]$-$\sigma$ relation, finding that $\left[\alpha/\rm{Fe}\right]=(0.395\pm0.010)\rm{log}_{10}\left(\sigma\right)-(0.627\pm0.002)$. We observe an anti-correlation between the residuals $\Delta\left[\alpha/\rm{Fe}\right]$ and the inclination-corrected $\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}$, which can be expressed as $\Delta\left[\alpha/\rm{Fe}\right]=(-0.057\pm0.008)\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}+(0.020\pm0.003)$. The anti-correlation appears to be driven by star-forming galaxies, with a gradient of $\Delta\left[\alpha/\rm{Fe}\right]\sim(-0.121\pm0.015)\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}$, although a weak relationship persists for the subsample of galaxies for which star formation has been quenched. We take this to be confirmation that disk-dominated galaxies have an extended duration of star formation. At a reference velocity dispersion of 200 km s$^{-1}$, we estimate an increase in half-mass formation time from $\sim$0.5 Gyr to $\sim$1.2 Gyr from low- to high-$\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}$ galaxies. Slow rotators do not appear to fit these trends. Their residual $\alpha$-enhancement is indistinguishable from other galaxies with $\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}\lessapprox0.4$, despite being both larger and more massive. This result shows that galaxies with $\lambda_{\,R_{\rm{e}}}^{\rm{\,eo}}\lessapprox0.4$ experience a similar range of star formation histories, despite their different physical structure and angular momentum., Comment: 12 pages, 9 figures

Dynamical models are crucial for uncovering the internal dynamics of galaxies, however, most of the results to date assume axisymmetry, which is not representative for a significant fraction of massive galaxies. Here, we build triaxial Schwarschild orbit-superposition models of galaxies taken from the SAMI Galaxy Survey, in order to reconstruct their inner orbital structure and mass distribution. The sample consists of 161 passive galaxies with total stellar masses in the range $10^{9.5}$ to $10^{12} M_{\odot}$. We find that the changes in internal structures within 1$R_{\rm e}$ are correlated with the total stellar mass of the individual galaxies. The majority of the galaxies in the sample ($73\% \pm 3\%$) are oblate, while $19\% \pm 3\%$ are mildly triaxial and $8\% \pm 2\%$ have triaxial/prolate shape. Galaxies with $\log M_{\star}/M_{\odot} > 10.50$ are more likely to be non-oblate. We find a mean dark matter fraction of $f_{\rm{DM}} = 0.28 \pm 0.20$, within 1$R_{\rm e}$. Galaxies with higher intrinsic ellipticity (flatter) are found to have more negative velocity anisotropy $\beta_r$ (tangential anisotropy). $\beta_r$ also shows an anti-correlation with the edge-on spin parameter \lam, so that $\beta_r$ decreases with increasing \lam. We see evidence of an increasing fraction of hot orbits with increasing stellar mass, while warm and cold orbits show a decreasing trend. We also find that galaxies with different ($V/\sigma$ - $h_3$) kinematic signatures have distinct combinations of orbits. These results are in agreement with a formation scenario in which slow- and fast-rotating galaxies form through two main channels., Comment: 40 pages. Accepted for publication in ApJ

We investigate the mean locally-measured velocity dispersions of ionised gas ($\sigma_{\rm gas}$) and stars ($\sigma_*$) for 1090 galaxies with stellar masses $\log\,(M_*/M_{\odot}) \geq 9.5$ from the SAMI Galaxy Survey. For star-forming galaxies, $\sigma_*$ tends to be larger than $\sigma_{\rm gas}$, suggesting that stars are in general dynamically hotter than the ionised gas (asymmetric drift). The difference between $\sigma_{\rm gas}$ and $\sigma_*$ ($\Delta\sigma$) correlates with various galaxy properties. We establish that the strongest correlation of $\Delta\sigma$ is with beam smearing, which inflates $\sigma_{\rm gas}$ more than $\sigma_*$, introducing a dependence of $\Delta\sigma$ 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 ionised gas emission, implying the gas velocity dispersion is strongly affected by the power source. In contrast, using the velocity dispersion measured from integrated spectra ($\sigma_{\rm aper}$) results in less correlation between the aperture-based $\Delta\sigma$ ($\Delta\sigma_{\rm aper}$) 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 $\Delta\sigma_{\rm aper}$ is much smaller than that of $\Delta\sigma$, a correlation between $\Delta\sigma_{\rm aper}$ and gas velocity gradient is still detected, implying there is a small bias in dynamical masses derived from stellar and ionised gas velocity dispersions., Comment: 18 pages, 13 figures

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 $\sim$1800 early and late-type galaxies with $\log(M_*/M_{\odot})>9.5$ as a function of mean environmental overdensity ($\Sigma_{5}$) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above $\log(M_*/M_{\odot})>10.5$, we detect a higher fraction ($\sim3.4\sigma$) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. 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 $\lambda_{R_e}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $\lambda_{\,R_e,intr}$, isolated-central galaxies have the highest $\lambda_{\,R_e,intr}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $\lambda_{\,R_e,intr}$ values as compared to galaxies at low environmental density. However, at fixed $\Sigma_{5}$, the mean $\lambda_{\,R_e,intr}$ differences for low and high-mass galaxies are of similar magnitude as when varying $\Sigma_{5}$ {($\Delta \lambda_{\,R_e,intr} \sim 0.05$. 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., Comment: 22 pages and 17 figures, accepted for publication in MNRAS. Abstract abridged for Arxiv. The key figures of the paper are: 6, 8, 10, and 12

We present spatially resolved stellar kinematics for 797 $z=0.6-1$ galaxies selected from the LEGA-C survey and construct axisymmetric Jeans models to quantify their dynamical mass and degree of rotational support. The survey is $K_s$-band selected, irrespective of color or morphological type, and allows for a first assessment of the stellar dynamical structure of the general $L^*$ galaxy population at large lookback time. Using light profiles from Hubble Space Telescope imaging as a tracer, our approach corrects for observational effects (seeing convolution and slit geometry), and uses well-informed priors on inclination, anisotropy and a non-luminous mass component. Tabulated data include total mass estimates in a series of spherical apertures (1, 5, and 10 kpc; 1$\times$ and 2$\times$\re), as well as rotational velocities, velocity dispersions and anisotropy. We show that almost all star-forming galaxies and $\sim$50\% of quiescent galaxies are rotation-dominated, with deprojected $V/\sigma\sim1-2$. Revealing the complexity in galaxy evolution, we find that the most massive star-forming galaxies are among the most rotation-dominated, and the most massive quiescent galaxies among the least rotation-dominated galaxies. These measurements set a new benchmark for studying galaxy evolution, using stellar dynamical structure for galaxies at large lookback time. Together with the additional information on stellar population properties from the LEGA-C spectra, the dynamical mass and $V/\sigma$ measurements presented here create new avenues for studying galaxy evolution at large lookback time., Comment: Accepted for publication in ApJ. Data table will be published with journal article and is now available upon request

How do we bridge the gap between the Galactic and the extragalactic? By focusing on the topic of stellar dynamics and stellar populations of the Milky Way and its siblings this virtual meeting aimed at connecting both fields that each bring unique perspectives to understanding how disk galaxies form and evolve. As this meeting took place during a global pandemic, we also give our perspective on the challenges and best practises for running a virtual meeting., Comment: Report of virtual meeting. All talks are available online at: https://extragalactic-milkyways.org/

We investigate the change in mean stellar population age and metallicity ([Z/H]) scaling relations for quiescent galaxies from intermediate redshift ($0.60\leq z\leq0.76$) using the LEGA-C Survey, to low redshift ($0.014\leq z\leq0.10$) using the SAMI Galaxy Survey. We find that, similarly to their low-redshift counterparts, the stellar metallicity of quiescent galaxies at $0.60\leq z\leq 0.76$ closely correlates with $M_*/R_\mathrm{e}$ (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 required by metal-rich stellar and supernova ejecta to escape the system and avoid being recycled into later stellar generations. On the other hand, we find no correlation between stellar age and $M_*/R_\mathrm{e}^2$ (stellar mass surface density $\Sigma$) in the LEGA-C sample, despite this being a strong relation at low redshift. We consider this change in the age--$\Sigma$ relation in the context of the redshift evolution of the star-forming and quiescent populations in the mass--size plane, and find our results can be explained as a consequence of 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 $z\sim 0$ age--$\Sigma$ relation is therefore a result of building up the quiescent and star-forming populations with galaxies that formed at a range of redshifts and so a range of surface densities., Comment: 18 pages, 11 figures, accepted to MNRAS

The existence of a kinematic morphology-density relation remains uncertain, and instead stellar mass appears the more dominant driver of galaxy kinematics. We investigate the dependence of the stellar spin parameter proxy $\lambda_{R_e}$ on environment using a marked cross-correlation method with data from the SAMI Galaxy Survey. Our sample contains 710 galaxies with spatially resolved stellar velocity and velocity dispersion measurements. By utilising the highly complete spectroscopic data from the GAMA survey, we calculate marked cross-correlation functions for SAMI galaxies using a pair count estimator and marks based on stellar mass and $\lambda_{R_e}$. We detect an anti-correlation of stellar kinematics with environment at the 3.2$\sigma$ level, such that galaxies with low $\lambda_{R_e}$ values are preferably located in denser galaxy environments. However, a significant correlation between stellar mass and environment is also found (correlation at 2.4$\sigma$), as found in previous works. We compare these results to mock-observations from the cosmological EAGLE simulations, where we find a similar significant $\lambda_{R_e}$ anti-correlation with environment, and a mass and environment correlation. We demonstrate that the environmental correlation of $\lambda_{R_e}$ is not caused by the mass-environment relation. The significant relationship between $\lambda_{R_e}$ and environment remains when we exclude slow rotators. The signals in SAMI and EAGLE are strongest on small scales (10-100 kpc) as expected from galaxy interactions and mergers. Our work demonstrates that the technique of marked correlation functions is an effective tool for detecting the relationship between $\lambda_{R_e}$ and environment., Comment: 10 pages, 4 figures, 1 table, accepted in to Astrophysical Journal

We present a new set of index-based measurements of [$\alpha$/Fe] for a sample of 2093 galaxies in the SAMI Galaxy Survey. Following earlier work, we fit a global relation between [$\alpha$/Fe] and the galaxy velocity dispersion $\sigma$ for red sequence galaxies, [$\alpha$/Fe]=(0.378$\pm$0.009)log($\sigma$/100)+(0.155$\pm$0.003). We observe a correlation between the residuals and the local environmental surface density, whereas no such relation exists for blue cloud galaxies. In the full sample, we find that elliptical galaxies in high-density environments are $\alpha$-enhanced by up to 0.057$\pm$0.014 dex at velocity dispersions $\sigma$<100 km/s, compared with those in low-density environments. This $\alpha$-enhancement is morphology-dependent, with the offset decreasing along the Hubble sequence towards spirals, which have an offset of 0.019$\pm$0.014 dex. At low velocity dispersion and controlling for morphology, we estimate that star formation in high-density environments is truncated $\sim1$ Gyr earlier than in low-density environments. For elliptical galaxies only, we find support for a parabolic relationship between [$\alpha$/Fe] and $\sigma$, with an environmental $\alpha$-enhancement of at least 0.03 dex. This suggests strong contributions from both environment and mass-based quenching mechanisms. However, there is no evidence for this behaviour in later morphological types., Comment: 15 pages, 9 figures. Revised after comments from referee

The Milky Way disk consists of two prominent components - a thick, alpha-rich, low-metallicity component and a thin, metal-rich, low-alpha component. External galaxies have been shown to contain thin and thick disk components, but whether distinct components in the [$\alpha$/Fe]-[Z/H] plane exist in other Milky Way-like galaxies is not yet known. We present VLT-MUSE observations of UGC 10738, a nearby, edge-on Milky Way-like galaxy. We demonstrate through stellar population synthesis model fitting that UGC 10738 contains alpha-rich and alpha-poor stellar populations with similar spatial distributions to the same components in the Milky Way. We discuss how the finding that external galaxies also contain chemically distinct disk components may act as a significant constraint on the formation of the Milky Way's own thin and thick disk., Comment: 8 pages, 5 figures, accepted for publication in ApJL

We study the Fundamental Plane (FP) for a volume- and luminosity-limited sample of 560 early-type galaxies from the SAMI survey. Using r-band sizes and luminosities from new Multi-Gaussian Expansion (MGE) photometric measurements, and treating luminosity as the dependent variable, the FP has coefficients a=1.294$\pm$0.039, b= 0.912$\pm$0.025, and zero-point c= 7.067$\pm$0.078. We leverage the high signal-to-noise of SAMI integral field spectroscopy, to determine how structural and stellar-population observables affect the scatter about the FP. The FP residuals correlate most strongly (8$\sigma$ significance) with luminosity-weighted simple-stellar-population (SSP) age. In contrast, the structural observables surface mass density, rotation-to-dispersion ratio, S\'ersic index and projected shape all show little or no significant correlation. We connect the FP residuals to the empirical relation between age (or stellar mass-to-light ratio $\Upsilon_\star$) and surface mass density, the best predictor of SSP age amongst parameters based on FP observables. We show that the FP residuals (anti-)correlate with the residuals of the relation between surface density and $\Upsilon_\star$. This correlation implies that part of the FP scatter is due to the broad age and $\Upsilon_\star$ distribution at any given surface mass density. Using virial mass and $\Upsilon_\star$ we construct a simulated FP and compare it to the observed FP. We find that, while the empirical relations between observed stellar population relations and FP observables are responsible for most (75%) of the FP scatter, on their own they do not explain the observed tilt of the FP away from the virial plane., Comment: 36 pages, 23 figures

We explore the connection between the kinematics, structures and stellar populations of massive galaxies at $0.610.5$) galaxies that span a wide range in morphology, star formation activity and environment, and therefore is representative of the massive galaxy population at $z\sim0.8$. We find that quiescent and star-forming galaxies occupy the parameter space of the $g$-band FP differently and thus have different distributions in the dynamical mass-to-light ratio ($M_{\rm dyn}/L_g$), largely owing to differences in the stellar age and recent star formation history, and, to a lesser extent, the effects of dust attenuation. In contrast, we show that both star-forming and quiescent galaxies lie on the same mass FP at $z\sim 0.8$, with a comparable level of intrinsic scatter about the plane. We examine the variation in $M_{\rm dyn}/M_*$ through the thickness of the mass FP, finding no significant residual correlations with stellar population properties, S\'ersic index, or galaxy overdensity. Our results suggest that, at fixed size and velocity dispersion, the variations in $M_{\rm dyn}/L_g$ of massive galaxies reflect an approximately equal contribution of variations in $M_*/L_g$, and variations in the dark matter fraction or initial mass function., Comment: 32 pages, 19 figures (including appendices); accepted for publication in ApJ

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 (DR3), 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 (370-570nm) and red (630-740nm) 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 parameterized 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 (AAO) Data Central., Comment: Accepted for publication in MNRAS. 27 pages, 21 figures. Data available at https://datacentral.org.au/ . See also http://sami-survey.org/

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 Sersic index. The observed trend could potentially originate from a differing BGG accretion history in virialised and evolving groups. Amongst 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 calls for further studies using a larger sample with higher signal-to-noise., Comment: 16 pages, 12 figures. Accepted for publication in ApJ

We use a sample of $z=0$ galaxies visually classified as slow rotators (SRs) in the EAGLE hydrodynamical simulations to explore the effect of galaxy mergers on their formation, characterise their intrinsic galaxy properties, and study the connection between quenching and kinematic transformation. SRs that have had major or minor mergers (mass ratios $\ge 0.3$ and $0.1-0.3$, respectively) tend to have a higher triaxiality parameter and ex-situ stellar fractions than those that had exclusively very minor mergers or formed in the absence of mergers ("no-merger" SRs). No-merger SRs are more compact, have lower black hole-to-stellar mass ratios and quenched later than other SRs, leaving imprints on their $z=0$ chemical composition. For the vast majority of SRs we find that quenching, driven by active galactic nuclei feedback, precedes kinematic transformation, except for satellite SRs, in which these processes happen in tandem. However, in $\approx 50$\% of these satellites, satellite-satellite mergers are responsible for their SR fate, while environment (i.e. tidal field and interactions with the central) can account for the transformation in the rest. By splitting SRs into kinematic sub-classes, we find that flat SRs prefer major mergers; round SRs prefer minor or very minor mergers; prolate SRs prefer gas-poor mergers. Flat and prolate SRs are more common among satellites hosted by massive halos ($>10^{13.6}\,\rm M_{\odot}$) and centrals of high masses ($M_{\star} > 10^{10.5}\, \rm M_{\odot}$). Although EAGLE galaxies display kinematic properties that broadly agree with observations, there are areas of disagreement, such as inverted stellar age and velocity dispersion profiles. We discuss these and how upcoming simulations can solve them., Comment: Accepted for publications in MNRAS. 22 pages and 20 figures. Main difference with previous version is additional panel in Fig. 7 showing Sersic index vs stellar mass for different merger histories

Large galaxy samples from multi-object IFS surveys now allow for a statistical analysis of the z~0 galaxy population using resolved kinematics. However, the improvement in number statistics comes at a cost, with multi-object IFS survey more severely impacted by the effect of seeing and lower S/N. We present an analysis of ~1800 galaxies from the SAMI Galaxy Survey and investigate the spread and overlap in the kinematic distributions of the spin parameter proxy $\lambda_{Re}$ as a function of stellar mass and ellipticity. For SAMI data, the distributions of galaxies identified as regular and non-regular rotators with \textsc{kinemetry} show considerable overlap in the $\lambda_{Re}$-$\varepsilon_e$ diagram. In contrast, visually classified galaxies (obvious and non-obvious rotators) are better separated in $\lambda_{Re}$ space, with less overlap of both distributions. Then, we use a Bayesian mixture model to analyse the observed $\lambda_{Re}$-$\log(M_*/M_{\odot})$ distribution. Below $\log(M_{\star}/M_{\odot})\sim10.5$, a single beta distribution is sufficient to fit the complete $\lambda_{Re}$ distribution, whereas a second beta distribution is required above $\log(M_{\star}/M_{\odot})\sim10.5$ to account for a population of low-$\lambda_{Re}$ galaxies. While the Bayesian mixture model presents the cleanest separation of the two kinematic populations, we find the unique information provided by visual classification of kinematic maps should not be disregarded in future studies. Applied to mock-observations from different cosmological simulations, the mixture model also predicts bimodal $\lambda_{Re}$ distributions, albeit with different positions of the $\lambda_{Re}$ peaks. Our analysis validates the conclusions from previous smaller IFS surveys, but also demonstrates the importance of using kinematic selection criteria that are dictated by the quality of the observed or simulated data., Comment: 30 pages and 17 figures, accepted for publication in MNRAS. Abstract abridged for Arxiv. The key figures of the paper are: 3, 7, 8, and 11

We investigate the stellar populations of passive spiral galaxies as a function of mass and environment, using integral field spectroscopy data from the Sydney-AAO Multi-object Integral field spectrograph Galaxy Survey. Our sample consists of $52$ cluster passive spirals and $18$ group/field passive spirals, as well as a set of S0s used as a control sample. The age and [Z/H] estimated by measuring Lick absorption line strength indices both at the center and within $1R_{\rm e}$ do not show a significant difference between the cluster and the field/group passive spirals. However, the field/group passive spirals with log(M$_\star$/M$_\odot)\gtrsim10.5$ show decreasing [$\alpha$/Fe] along with stellar mass, which is $\sim0.1$ dex smaller than that of the cluster passive spirals. We also compare the stellar populations of passive spirals with S0s. In the clusters, we find that passive spirals show slightly younger age and lower [$\alpha$/Fe] than the S0s over the whole mass range. In the field/group, stellar populations show a similar trend between passive spirals and S0s. In particular, [$\alpha$/Fe] of the field/group S0s tend to be flattening with increasing mass above log(M$_\star$/M$_\odot)\gtrsim10.5$, similar to the field/group passive spirals. We relate the age and [$\alpha$/Fe] of passive spirals to their mean infall time in phase-space; we find a positive correlation, in agreement with the prediction of numerical simulations. We discuss the environmental processes that can explain the observed trends. The results lead us to conclude that the formation of the passive spirals and their transformation into S0s may significantly depend on their environments., Comment: 13 pages, 12 figures, 1 table, accepted for publication in ApJ

We use the Fundamental Plane (FP) to measure the redshift evolution of the dynamical mass-to-light ratio ($M_{\mathrm{dyn}}/L$) and the dynamical-to-stellar mass ratio ($M_{\mathrm{dyn}}/M_*$). Although conventionally used to study the properties of early-type galaxies, we here obtain stellar kinematic measurements from the Large Early Galaxy Astrophysics Census (LEGA-C) Survey for a sample of $\sim1400$ massive ($\log( M_*/M_\odot) >10.5$) galaxies at $0.6

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 remains 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 $v/{\sigma}$ 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 S\'ersic index distributions with spiral galaxies shows that the rotationally supported S0s with $v/{\sigma}$ 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 ($10^{13} < M_{halo} < 10^{14}$)., Comment: 14 pages, 12 figures, accepted for publication in MNRAS

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 (SAMI) Galaxy Survey. The spatially-resolved rotation velocity (V) and velocity dispersion ($\sigma$) 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 $\sigma$ 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 $\sigma$ 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 $\lambda_R$ indicates bulges are pressure-dominated systems and disks are supported by rotation; (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., Comment: 22 pages, 21 figures; Accepted for publication in MNRAS

We infer the intrinsic ionised gas kinematics for 383 star-forming galaxies across a range of integrated star-formation rates (SFR $\in [10^{-3}, 10^2]$ M$_\odot$ yr$^{-1}$) at $z \lesssim 0.1$ using a consistent 3D forward-modelling technique. The total sample is a combination of galaxies from the SAMI Galaxy Survey and DYNAMO survey. For typical low-$z$ galaxies taken from the SAMI Galaxy Survey, we find the vertical velocity dispersion ($\sigma_{v, z}$) to be positively correlated with measures of star-formation rate, stellar mass, HI gas mass, and rotational velocity. The greatest correlation is with star-formation rate surface density ($\Sigma_\text{SFR}$). Using the total sample, we find $\sigma_{v, z}$ increases slowly as a function of integrated star-formation rate in the range SFR $\in$ [$10^{-3}$, 1] M$_\odot$ yr$^{-1}$ from $17\pm3$ km s$^{-1}$ to $24\pm5$ km s$^{-1}$ followed by a steeper increase up to $\sigma_{v, z}$ $\sim 80$ km s$^{-1}$ for SFR $\gtrsim 1$ M$_\odot$ yr$^{-1}$. This is consistent with recent theoretical models that suggest a $\sigma_{v, z}$ floor driven by star-formation feedback processes with an upturn in $\sigma_{v, z}$ at higher SFR driven by gravitational transport of gas through the disc., Comment: 27 pages, 10 figures, accepted for MNRAS

We examine the stellar population radial gradients (age, metallicity and [$\alpha/$Fe]) of $\sim$ 100 passive central galaxies up to $\sim 2 R_e$. The targeted groups have a halo mass range spanning from $11 < \log(M_{200}/M_{\odot}) < 15$, in the SAMI Galaxy Survey. The main goal of this work is to determine whether central galaxies have different stellar population properties when compared to similarly massive satellite galaxies. We find negative metallicity radial gradients, which become shallower with increasing stellar mass. The age and [$\alpha$/Fe] gradients are consistent with zero or slightly positive. [$\alpha$/Fe] gradients become more negative with increasing mass, while age gradients do not show any significant trend with mass. We do not observe a significant difference between the stellar population gradients of central and satellite galaxies, at fixed stellar mass. The mean metallicity gradients are $\overline{\Delta [Z/H]/\Delta \log(r/R_e)} = -0.25 \pm 0.03$ for central galaxies and $\overline{\Delta [Z/H]/\Delta \log(r/R_e)} = -0.30 \pm 0.01$ for satellites. The mean age and [$\alpha$/Fe] gradients are consistent between central and satellite galaxies, within the uncertainties, with a mean value of $\overline{\Delta \textrm{log (Age/Gyr)}/\Delta \log(r/R_e)} = 0.13 \pm 0.03$ for centrals and $\overline{\Delta \textrm{log (Age/Gyr)}/\Delta \log(r/R_e)} = 0.17 \pm 0.01$ for satellite and $\overline{\Delta [\alpha/Fe]/\Delta \log(r/R_e)} = 0.01 \pm 0.03$ for centrals and $\overline{\Delta [\alpha/Fe]/\Delta \log(r/R_e)} = 0.08 \pm 0.01$ for satellites. This evidence suggests that the central region of central passive galaxies form in a similar fashion to satellite passive galaxies, in agreement with a two-phase formation scenario., Comment: 20 pages. Accepted for publication in ApJ

In this letter, we investigate the impact of environment on integrated and spatially-resolved stellar kinematics of a sample of massive, quiescent galaxies at intermediate redshift ($0.6

Recent integral field spectroscopy observations have found that about 11% of galaxies show star-gas misalignment. The misalignment possibly results from external effects such as gas accretion, interaction with other objects, and other environmental effects, hence providing clues to these effects. We explore the properties of misaligned galaxies using Horizon-AGN, a large-volume cosmological simulation, and compare the result with the result of the Sydney-AAO Multi-object integral field spectrograph (SAMI) Galaxy Survey. Horizon-AGN can match the overall misalignment fraction and reproduces the distribution of misalignment angles found by observations surprisingly closely. The misalignment fraction is found to be highly correlated with galaxy morphology both in observations and in the simulation: early-type galaxies are substantially more frequently misaligned than late-type galaxies. The gas fraction is another important factor associated with misalignment in the sense that misalignment increases with decreasing gas fraction. However, there is a significant discrepancy between the SAMI and Horizon-AGN data in the misalignment fraction for the galaxies in dense (cluster) environments. We discuss possible origins of misalignment and disagreement., Comment: 23 pages with 15 figures. Accepted for publication in ApJ