arXiv subjects

A. R. Lopez-Sanchez

Publications and source records attributed to A. R. Lopez-Sanchez.

At least 19 recordsLinked to original sources

arXiv2022

Galaxy And Mass Assembly: Galaxy Morphology in the Green Valley, Prominent rings and looser Spiral Arms

Galaxies broadly fall into two categories: star-forming (blue) galaxies and quiescent (red) galaxies. In between, one finds the less populated ``green valley". Some of these galaxies are suspected to be in the process of ceasing their star-formation through a gradual exhaustion of gas supply or already dead and are experiencing a rejuvenation of star-formation through fuel injection. We use the Galaxy And Mass Assembly database and the Galaxy Zoo citizen science morphological estimates to compare the morphology of galaxies in the green valley against those in the red sequence and blue cloud. Our goal is to examine the structural differences within galaxies that fall in the green valley, and what brings them there. Previous results found disc features such as rings and lenses are more prominently represented in the green valley population. We revisit this with a similar sized data set of galaxies with morphology labels provided by the Galaxy Zoo for the GAMA fields based on new KiDS images. Our aim is to compare qualitatively the results from expert classification to that of citizen science. We observe that ring structures are indeed found more commonly in green valley galaxies compared to their red and blue counterparts. We suggest that ring structures are a consequence of disc galaxies in the green valley actively exhibiting characteristics of fading discs and evolving disc morphology of galaxies. We note that the progression from blue to red correlates with loosening spiral arm structure.

astro-ph.GA↗

arXiv2021

Galaxy And Mass Assembly (GAMA): The environmental impact on SFR and metallicity in galaxy groups

We present a study of the relationships and environmental dependencies between stellar mass, star formation rate, and gas metallicity for more than 700 galaxies in groups up to redshift 0.35 from the Galaxy And Mass Assembly (GAMA) survey. To identify the main drivers, our sample was analyzed as a function of group-centric distance, projected galaxy number density, and stellar mass. By using control samples of more than 16000 star-forming field galaxies and volume limited samples, we find that the highest enhancement in SFR (0.3 dex) occurs in galaxies with the lowest local density. In contrast to previous work, our data show small enhancements of $\sim$0.1 dex in SFR for galaxies at the highest local densities or group-centric distances. Our data indicates quenching in SFR only for massive galaxies, suggesting that stellar mass might be the main driver of quenching processes for star forming galaxies. We can discard a morphological driven quenching, since the Sérsic index distribution for group and control galaxies are similar. The gas metallicity does not vary drastically. It increases $\sim$0.08 dex for galaxies at the highest local densities, and decreases for galaxies at the highest group-centric distances, in agreement with previous work. Altogether, the local density, rather than group-centric distance, shows the stronger impact in enhancing both, the SFR and gas metallicity. We applied the same methodology to galaxies from the IllustrisTNG simulations, and although we were able to reproduce the general observational trends, the differences between group and control samples only partially agree with the observations

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arXiv2020

Centrally concentrated molecular gas driving galactic-scale ionised gas outflows in star-forming galaxies

We perform a joint-analysis of high spatial resolution molecular gas and star-formation rate (SFR) maps in main-sequence star-forming galaxies experiencing galactic-scale outflows of ionised gas. Our aim is to understand the mechanism that determines which galaxies are able to launch these intense winds. We observed CO(1-0) at 1" resolution with ALMA in 16 edge-on galaxies, which also have 2" spatial resolution optical integral field observations from the SAMI Galaxy Survey. Half the galaxies in the sample were previously identified as harbouring intense and large-scale outflows of ionised gas ("outflow-types"), the rest serve as control galaxies. The dataset is complemented by integrated CO(1-0) observations from the IRAM 30-m telescope to probe the total molecular gas reservoirs. We find that the galaxies powering outflows do not possess significantly different global gas fractions or star-formation efficiencies when compared with a control sample. However, the ALMA maps reveal that the molecular gas in the outflow-type galaxies is distributed more centrally than in the control galaxies. For our outflow-type objects, molecular gas and star-formation is largely confined within their inner effective radius ($\rm r_{eff}$), whereas in the control sample the distribution is more diffuse, extending far beyond $\rm r_{eff}$. We infer that outflows in normal star-forming galaxies may be caused by dynamical mechanisms that drive molecular gas into their central regions, which can result in locally-enhanced gas surface density and star-formation.

astro-ph.GA↗

arXiv2019

ASKAP Commissioning Observations of the GAMA 23 Field

We have observed the G23 field of the Galaxy And Mass Assembly (GAMA) survey using the Australian Square Kilometre Array Pathfinder (ASKAP) in its commissioning phase, to validate the performance of the telescope and to characterize the detected galaxy populations. This observation covers $\sim$48 deg$^2$ with synthesized beam of 32.7$^{\prime\prime}$ by 17.8$^{\prime\prime}$ at 936 MHz, and $\sim$39 deg$^2$ with synthesized beam of 15.8$^{\prime\prime}$ by 12.0$^{\prime\prime}$ at 1320 MHz. At both frequencies, the r.m.s. (root-mean-square) noise is $\sim$0.1 mJy/beam. We combine these radio observations with the GAMA galaxy data, which includes spectroscopy of galaxies that are i-band selected with a magnitude limit of 19.2. Wide-field Infrared Survey Explorer (WISE) infrared (IR) photometry is used to determine which galaxies host an active galactic nucleus (AGN). In properties including source counts, mass distributions, and IR vs. radio luminosity relation, the ASKAP detected radio sources behave as expected. Radio galaxies have higher stellar mass and luminosity in IR, optical and UV than other galaxies. We apply optical and IR AGN diagnostics and find that they disagree for $\sim$30% of the galaxies in our sample. We suggest possible causes for the disagreement. Some cases can be explained by optical extinction of the AGN, but for more than half of the cases we do not find a clear explanation. Radio sources are more likely ($\sim$6%) to have an AGN than radio quiet galaxies ($\sim$1%), but the majority of AGN are not detected in radio at this sensitivity.

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arXiv2018

The SAMI Galaxy Survey: Exploring the gas-phase Mass-Metallicity Relation

We present a detailed exploration of the stellar mass vs. gas-phase metallicity relation (MZR) using integral field spectroscopy data obtained from ~1000 galaxies observed by the SAMI Galaxy survey. These spatially resolved spectroscopic data allow us to determine the metallicity within the same physical scale (Reff) for different calibrators. The shape of the MZ relations is very similar between the different calibrators, while there are large offsets in the absolute values of the abundances. We confirm our previous results derived using the spatially resolved data provided by the CALIFA and MaNGA surveys: (1) we do not find any significant secondary relation of the MZR with either the star formation rate (SFR) nor the specific SFR (SFR/Mass) for any of the calibrators used in this study, based on the analysis of the {individual} residuals, (2) if there is a dependence with the SFR, it is weaker than the reported one ($r_c\sim -$0.3), it is confined to the low mass regime (M*<10$^9$Msun) or high SFR regimes, and it does not produce any significant improvement in the {description of the average population of galaxies. The aparent disagreement with published results based on single fiber spectroscopic data could be due to (i) the interpretation of the secondary relation itself, (ii) the lower number of objects sampled at the low mass regime by the current study, or (iii) the presence of extreme star-forming galaxies that drive the secondary relation in previous results

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arXiv2018

Galaxy and Mass Assembly (GAMA): Accurate number densities & environments of massive ultracompact galaxies at 0.02 < z < 0.3

Massive Ultracompact Galaxies (MUGs) are common at z=2-3, but very rare in the nearby Universe. Simulations predict that the few surviving MUGs should reside in galaxy clusters, whose large relative velocities prevent them from merging, thus maintaining their original properties (namely stellar populations, masses, sizes and dynamical state). We take advantage of the high-completeness, large-area spectroscopic GAMA survey, complementing it with deeper imaging from the KiDS and VIKING surveys. We find a set of 22 bona-fide MUGs, defined as having high stellar mass (>8x10^10 M_Sun) and compact size (R_e<2 Kpc) at 0.02 < z < 0.3. An additional set of 7 lower-mass objects (6x10^10 < M_star/M_Sun < 8x10^10) are also potential candidates according to typical mass uncertainties. The comoving number density of MUGs at low redshift (z < 0.3) is constrained at $(1.0\pm 0.4)x 10^-6 Mpc^-3, consistent with galaxy evolution models. However, we find a mixed distribution of old and young galaxies, with a quarter of the sample representing (old) relics. MUGs have a predominantly early/swollen disk morphology (Sersic index 1 ~ 10^10 M_Sun Kpc^-2). Interestingly, a large fraction feature close companions -- at least in projection -- suggesting that many (but not all) reside in the central regions of groups. Halo masses show these galaxies inhabit average-mass groups. As MUGs are found to be almost equally distributed among environments of different masses, their relative fraction is higher in more massive overdensities, matching the expectations that some of these galaxies fell in these regions at early times. However, there must be another channel leading some of these galaxies to an abnormally low merger history because our sample shows a number of objects that do not inhabit particularly dense environments. (abridged)

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arXiv2017

Radio Galaxy Zoo: A Search for Hybrid Morphology Radio Galaxies

Hybrid morphology radio sources are a rare type of radio galaxy that display different Fanaroff-Riley classes on opposite sides of their nuclei. To enhance the statistical analysis of hybrid morphology radio sources, we embarked on a large-scale search of these sources within the international citizen science project, Radio Galaxy Zoo (RGZ). Here, we present 25 new candidate hybrid morphology radio galaxies. Our selected candidates are moderate power radio galaxies (L_median = 4.7x10^{24} W/(Hz sr) at redshifts 0.14 1Mpc) radio galaxies, one resides at a centre of a galaxy cluster, and one is hosted by a rare green bean galaxy. Although the origin of the hybrid morphology radio galaxies is still unclear, this type of radio source starts depicting itself as a rather diverse class. We discuss hybrid radio morphology formation in terms of the radio source environment (nurture) and intrinsically occurring phenomena (nature; activity cessation and amplification), showing that these peculiar radio galaxies can be formed by both mechanisms. While high angular resolution follow-up observations are still necessary to confirm our candidates, we demonstrate the efficacy of the Radio Galaxy Zoo in the pre-selection of these sources from all-sky radio surveys, and report the reliability of citizen scientists in identifying and classifying complex radio sources.

astro-ph.GA↗

arXiv2017

Galaxy And Mass Assembly (GAMA): the G02 field, Herschel-ATLAS target selection and Data Release 3

We describe data release 3 (DR3) of the Galaxy And Mass Assembly (GAMA) survey. The GAMA survey is a spectroscopic redshift and multi-wavelength photometric survey in three equatorial regions each of 60.0 deg^2 (G09, G12, G15), and two southern regions of 55.7 deg^2 (G02) and 50.6 deg^2 (G23). DR3 consists of: the first release of data covering the G02 region and of data on H-ATLAS sources in the equatorial regions; and updates to data on sources released in DR2. DR3 includes 154809 sources with secure redshifts across four regions. A subset of the G02 region is 95.5% redshift complete to r<19.8 over an area of 19.5 deg^2, with 20086 galaxy redshifts, that overlaps substantially with the XXL survey (X-ray) and VIPERS (redshift survey). In the equatorial regions, the main survey has even higher completeness (98.5%), and spectra for about 75% of H-ATLAS filler targets were also obtained. This filler sample extends spectroscopic redshifts, for probable optical counterparts to H-ATLAS sub-mm sources, to 0.8 mag deeper (r<20.6) than the GAMA main survey. There are 25814 galaxy redshifts for H-ATLAS sources from the GAMA main or filler surveys. GAMA DR3 is available at the survey website (www.gama-survey.org/dr3/).

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arXiv2017

Galaxy and Mass Assembly (GAMA): Small-scale anisotropic galaxy clustering and the pairwise velocity dispersion of galaxies

The galaxy pairwise velocity dispersion (PVD) can provide important tests of non-standard gravity and galaxy formation models. We describe measurements of the PVD of galaxies in the Galaxy and Mass Assembly (GAMA) survey as a function of projected separation and galaxy luminosity. Due to the faint magnitude limit ($r < 19.8$) and highly-complete spectroscopic sampling of the GAMA survey, we are able to reliably measure the PVD to smaller scales ($r_\bot = 0.01$ Mpc/h) than previous work. The measured PVD at projected separations $r_\bot <~ 1$ Mpc/h increases near-monotonically with increasing luminosity from $σ\approx 200$ km/s at $M_r = -17$ mag to $σ\approx 600$ km/s at $M_r \approx -22$ mag. Analysis of the Gonzalez-Perez (2014) GALFORM semi-analytic model yields no such trend of PVD with luminosity: the model over-predicts the PVD for faint galaxies. This is most likely a result of the model placing too many low-luminosity galaxies in massive halos.

astro-ph.CO↗

arXiv2017

Morpho-kinematic properties of field S0 bulges in the CALIFA survey

We study a sample of 28 S0 galaxies extracted from the integral-field spectroscopic (IFS) survey CALIFA. We combine an accurate two-dimensional (2D) multi-component photometric decomposition with the IFS kinematic properties of their bulges to understand their formation scenario. Our final sample is representative of S0s with high stellar masses ($M_{star}/M_{sun} > 10^{10}$). They lay mainly on the red sequence and live in relatively isolated environments similar to that of the field and loose groups. We use our 2D photometric decomposition to define the size and photometric properties of the bulges, as well as their location within the galaxies. We perform mock spectroscopic simulations mimicking our observed galaxies to quantify the impact of the underlying disc on our bulge kinematic measurements ($λ$ and $v/σ$). We compare our bulge corrected kinematic measurements with the results from Schwarzschild dynamical modelling. The good agreement confirms the robustness of our results and allows us to use bulge reprojected values of $λ$ and $v/σ$. We find that the photometric ($n$ and $B/T$) and kinematic ($v/σ$ and $λ$) properties of our field S0 bulges are not correlated. We demonstrate that this morpho-kinematic decoupling is intrinsic to the bulges and it is not due to projection effects. We conclude that photometric diagnostics to separate different types of bulges (disc-like vs classical) might not be useful for S0 galaxies. The morpho-kinematics properties of S0 bulges derived in this paper suggest that they are mainly formed by dissipation processes happening at high redshift, but dedicated high-resolution simulations are necessary to better identify their origin.

astro-ph.GA↗

arXiv2017

The SAMI Galaxy Survey: the intrinsic shape of kinematically selected galaxies

Using the stellar kinematic maps and ancillary imaging data from the Sydney AAO Multi Integral field (SAMI) Galaxy Survey, the intrinsic shape of kinematically-selected samples of galaxies is inferred. We implement an efficient and optimised algorithm to fit the intrinsic shape of galaxies using an established method to simultaneously invert the distributions of apparent ellipticities and kinematic misalignments. The algorithm output compares favourably with previous studies of the intrinsic shape of galaxies based on imaging alone and our re-analysis of the ATLAS3D data. Our results indicate that most galaxies are oblate axisymmetric. We show empirically that the intrinsic shape of galaxies varies as a function of their rotational support as measured by the "spin" parameter proxy Lambda_Re. In particular, low spin systems have a higher occurrence of triaxiality, while high spin systems are more intrinsically flattened and axisymmetric. The intrinsic shape of galaxies is linked to their formation and merger histories. Galaxies with high spin values have intrinsic shapes consistent with dissipational minor mergers, while the intrinsic shape of low-spin systems is consistent with dissipationless multi-merger assembly histories. This range in assembly histories inferred from intrinsic shapes is broadly consistent with expectations from cosmological simulations.

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arXiv2017

The Local Volume HI Survey: star formation properties

We built a multi-wavelength dataset for galaxies from the Local Volume HI Survey (LVHIS), which comprises 82 galaxies. We also select a sub-sample of ten large galaxies for investigating properties in the galactic outskirts. The LVHIS sample covers nearly four orders of magnitude in stellar mass and two orders of magnitude in HI mass fraction (fHI). The radial distribution of HI gas with respect to the stellar disc is correlated with fHI but with a large scatter. We confirm the previously found correlations between the total HI mass and star formation rate (SFR), and between HI surface densities and SFR surface densities beyond R25. However, the former correlation becomes much weaker when the average surface densities rather than total mass or rate are considered, and the latter correlation also becomes much weaker when the effect of stellar mass is removed or controlled. Hence the link between SFR and HI is intrinsically weak in these regions, consistent with what was found on kpc scales in the galactic inner regions. We find a strong correlation between the SFR surface density and the stellar mass surface density, which is consistent with the star formation models where the gas is in quasi-equilibrium with the mid-plane pressure. We find no evidence for HI warps to be linked with decreasing star forming efficiencies.

astro-ph.GA↗

arXiv2017

The SAMI Galaxy Survey: mass as the driver of the kinematic morphology - density relation in clusters

We examine the kinematic morphology of early-type galaxies (ETGs) in eight galaxy clusters in the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. The clusters cover a mass range of 14.2<log(M_200/M_odot)<15.2 and we measure spatially-resolved stellar kinematics for 315 member galaxies with stellar masses 10.0<log(M_*/M_odot)<11.7 within 1R_200 of the cluster centers. We calculate the spin parameter, lambda_R and use that to classify the kinematic morphology of the galaxies as fast or slow rotators. The total fraction of slow rotators in the early-type galaxy population, F_SR=0.14+/-0.02 and does not depend on host cluster mass. Across the eight clusters, the fraction of slow rotators increases with increasing local overdensity. We also find that the slow-rotator fraction increases at small clustercentric radii (R_cl<0.3R_200), and note that there is also an increase in slow-rotator fraction at R_cl~0.6R_200. The slow rotators at these larger radii reside in cluster substructure. We find the strongest increase in slow-rotator fraction occurs with increasing stellar mass. After accounting for the strong correlation with stellar mass, we find no significant relationship between spin parameter and local overdensity in the cluster environment. We conclude that the primary driver for the kinematic morphology--density relationship in galaxy clusters is the changing distribution of galaxy stellar mass with local environment. The presence of slow rotators in substructure suggests that the cluster kinematic morphology--density relationship is a result of mass segregation of slow-rotating galaxies forming in groups that later merge with clusters and sink to the cluster center via dynamical friction.

astro-ph.GA↗

arXiv2016

Galaxy And Mass Assembly (GAMA): Gas Fuelling of Spiral Galaxies in the Local Universe I. - The Effect of the Group Environment on Star Formation in Spiral Galaxies

Abridged - We quantify the effect of the galaxy group environment (for 12.5 < log(M_group/Msun) < 14.0) on the star formation rates of the (morphologically-selected) population of disk-dominated local Universe spiral galaxies (z < 0.13) with stellar masses log(M*/Msun) > 9.5. Within this population, we find that, while a small minority of group satellites are strongly quenched, the group centrals, and the large majority of satellites exhibit levels of SFR indistinguishable from ungrouped "field" galaxies of the same M*, albeit with a higher scatter, and for all M*. Modelling these results, we deduce that disk-dominated satellites continue to be characterized by a rapid cycling of gas into and out of their ISM at rates similar to those operating prior to infall, with the on-going fuelling likely sourced from the group intrahalo medium (IHM) on Mpc scales, rather than from the circum-galactic medium on 100kpc scales. Consequently, the color-density relation of the galaxy population as a whole would appear to be primarily due to a change in the mix of disk- and spheroid-dominated morphologies in the denser group environment compared to the field, rather than to a reduced propensity of the IHM in higher mass structures to cool and accrete onto galaxies. We also suggest that the inferred substantial accretion of IHM gas by satellite disk-dominated galaxies will lead to a progressive reduction in their specific angular momentum, thereby representing an efficient secular mechanism to transform morphology from star-forming disk-dominated types to more passive spheroid-dominated types.

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arXiv2016

Using the local gas-phase oxygen abundances to explore a metallicity-dependence in SNe Ia luminosities

We present an analysis of the gas-phase oxygen abundances of a sample of 28 galaxies in the local Universe (z < 0.02) hosting Type Ia Supernovae (SNe Ia). The data were obtained with the 4.2m William Herschel Telescope (WHT). We derive local oxygen abundances for the regions where the SNe Ia exploded by calculating oxygen gradients through each galaxy (when possible) or assuming the oxygen abundance of the closest HII region. The sample selection only considered galaxies for which distances not based on the the SN Ia method are available. Then, we use a principal component analysis to study the dependence of the absolute magnitudes on the color of the SN Ia, the oxygen abundances of the region where they exploded, and the stretch of the SN light curve. We demonstrate that our previous result suggesting a metallicity-dependence on the SN Ia luminosity for not-reddened SNe Ia (Moreno-Raya et al. 2016) can be extended to our whole sample. These results reinforce the need of including a metallicity proxy, such as the oxygen abundance of the host galaxy, to minimize the systematic effect induced by the metallicity-dependence of the SN Ia luminosity in future studies of SNe Ia at cosmological distances.

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arXiv2016

Radio Galaxy Zoo: discovery of a poor cluster through a giant wide-angle tail radio galaxy

We have discovered a previously unreported poor cluster of galaxies (RGZ-CL J0823.2+0333) through an unusual giant wide-angle tail radio galaxy found in the Radio Galaxy Zoo project. We obtained a spectroscopic redshift of $z=0.0897$ for the E0-type host galaxy, 2MASX J08231289+0333016, leading to M$_r = -22.6$ and a $1.4\,$GHz radio luminosity density of $L_{\rm 1.4} = 5.5\times10^{24}$ W Hz$^{-1}$. These radio and optical luminosities are typical for wide-angle tailed radio galaxies near the borderline between Fanaroff-Riley (FR) classes I and II. The projected largest angular size of $\approx8\,$arcmin corresponds to $800\,$kpc and the full length of the source along the curved jets/trails is $1.1\,$Mpc in projection. X-ray data from the XMM-Newton archive yield an upper limit on the X-ray luminosity of the thermal emission surrounding RGZ J082312.9+033301,at $1.2-2.6\times10^{43}$ erg s$^{-1}$ for assumed intra-cluster medium temperatures of $1.0-5.0\,$keV. Our analysis of the environment surrounding RGZ J082312.9+033301 indicates that RGZ J082312.9+033301 lies within a poor cluster. The observed radio morphology suggests that (a) the host galaxy is moving at a significant velocity with respect to an ambient medium like that of at least a poor cluster, and that (b) the source may have had two ignition events of the active galactic nucleus with $10^7\,$yrs in between. This reinforces the idea that an association between RGZ J082312.9+033301, and the newly discovered poor cluster exists.

astro-ph.GA↗

arXiv2016

Supernova 2014J at M82: II. Direct Analysis of Spectra Obtained with Isaac Newton and William Herschel Telescopes

We analyze a time series of optical spectra of SN~2014J from almost two weeks prior to maximum to nearly four months after maximum. We perform our analysis using the SYNOW code, which is well suited to track the distribution of the ions with velocity in the ejecta. We show that almost all of the spectral features during the entire epoch can be identified with permitted transitions of the common ions found in normal SNe Ia in agreement with previous studies. We show that 2014J is a relatively normal SN Ia. At early times the spectral features are dominated by Si II, S II, Mg II, and Ca II. These ions persist to maximum light with the appearance of Na I and Mg I. At later times iron-group elements also appear, as expected in the stratified abundance model of the formation of normal type Ia SNe. We do not find significant spectroscopic evidence for oxygen, until 100 days after maximum light. The +100 day identification of oxygen is tentative, and would imply significant mixing of unburned or only slight processed elements down to a velocity of 6,000 km/s. Our results are in relatively good agreement with other analyses in the IR. We briefly compare SN 2011fe to SN 2014J and conclude that the differences could be due to different central densities at ignition or differences in the C/O ratio of the progenitors.

astro-ph.SR↗

arXiv2015

Galaxy And Mass Assembly (GAMA): The Bright Void Galaxy Population in the Optical and Mid-IR

We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii $>10~h^{-1}$ Mpc. Utilising the GAMA equatorial survey, 592 void galaxies are identified out to z~0.1 brighter than $M_{r} = -18.4$, our magnitude completeness limit. Using the $W_{\rm{Hα}}$ vs. [NII]/H$α$ (WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than $5\times10^{9}$ M$_{\odot}$, we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the WHAN diagnostic diagram, else they lack any emission lines in their spectra. When matched to WISE mid-IR photometry, these passive and retired galaxies exhibit a range of mid-IR colour, with a number of void galaxies exhibiting [4.6]-[12] colours inconsistent with completely quenched stellar populations, with a similar spread in colour seen for a randomly drawn non-void comparison sample. We hypothesise that a number of these galaxies host obscured star formation, else they are star forming outside of their central regions targeted for single fibre spectroscopy. When matched to a randomly drawn sample of non-void galaxies, the void and non-void galaxies exhibit similar properties in terms of optical and mid-IR colour, morphology, and star formation activity, suggesting comparable mass assembly and quenching histories. A trend in mid-IR [4.6]-[12] colour is seen, such that both void and non-void galaxies with quenched/passive colours <1.5 typically have masses higher than $10^{10}$ M$_{\odot}$, where internally driven processes play an increasingly important role in galaxy evolution.

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