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Context One of the most fundamental scaling relations in galaxies is observed between metallicity and stellar mass – the mass-metallicity relation (MZR) – although recently a stronger dependence of the gas-phase metallicity with the galactic gravitational potential (ΦZR) has been reported. Further dependences of metallicity on other galaxy properties have been revealed, with the star formation rate (SFR) being one of the most studied and debated secondary parameters in the relation (the so-called fundamental metallicity relation). Aims. In this work we explore the dependence of the gas-phase metallicity residuals from the MZR and ΦZR on different galaxy properties in the search for the most fundamental scaling relation in galaxies. Methods. We applied a random forest regressor algorithm on a sample of 3430 nearby star-forming galaxies from the SDSS-IV MaNGA survey. Using this technique, we explored the effect of 147 additional parameters on the global oxygen abundance residuals obtained after subtracting the MZR. Alternatively, we followed a similar approach with the metallicity residuals from the ΦZR. Results. The stellar metallicity of the galaxy is revealed as the secondary parameter in both the MZR and the ΦZR, ahead of the SFR. This parameter reduces the scatter in the relations ∼10 − 15%. We find the 3D relation between gravitational potential, gas metallicity, and stellar metallicity to be the most fundamental metallicity relation observed in galaxies. [ABSTRACT FROM AUTHOR]

The connection between quenching mechanisms, which rapidly turn star-forming systems into quiescent, and the properties of the galaxy population remains difficult to discern. In this work we investigate the physical properties of MaNGA and SAMI galaxies at different stages of their star formation history. Specifically, we compare galaxies with signatures of recent quenching (Quenched) – |$\rm H \, \alpha$| in absorption and low Dn (4000) – with the rest of the low star-forming and active population (Retired and Ageing, respectively). The analysis is performed in terms of characteristics such as the total stellar mass, half-light radius, velocity-to-dispersion ratio, metallicity, and environment. We find that the Ageing population comprises a heterogeneous mixture of galaxies, preferentially late-type systems, with diverse physical properties. Retired galaxies, formerly Ageing or Quenched systems, are dominated by early-type high-mass galaxies found both at low and dense environments. Most importantly, we find that recently quenched galaxies are consistent with a population of compact low-mass satellite systems, with higher metallicities than their Ageing analogues. We argue that this is compatible with being quenched after undergoing a star-burst phase induced by environmental processes (e.g. ram pressure). However, we also detect a non-negligible fraction of field central galaxies likely quenched by internal processes. This study highlights that, in order to constrain the mechanisms driving galaxy evolution, it is crucial to distinguish between old (Retired) and recently quenched galaxies, thus requiring at least two estimates of the specific star formation rate over different time-scales. [ABSTRACT FROM AUTHOR]

Type IIn supernovae occur when stellar explosions are surrounded by dense hydrogen-rich circumstellar matter. The dense circumstellar matter is likely formed by extreme mass loss from their progenitors shortly before they explode. The nature of Type IIn supernova progenitors and the mass-loss mechanism forming the dense circumstellar matter are still unknown. In this work, we investigate whether Type IIn supernova properties and their local environments are correlated. We use Type IIn supernovae with well-observed light curves and host-galaxy integral field spectroscopic data so that we can estimate both supernova and environmental properties. We find that Type IIn supernovae with a higher peak luminosity tend to occur in environments with lower metallicity and/or younger stellar populations. The circumstellar matter density around Type IIn supernovae is not significantly correlated with metallicity, so the mass-loss mechanism forming the dense circumstellar matter around Type IIn supernovae might be insensitive to metallicity. [ABSTRACT FROM AUTHOR]

Despite the importance of feedback from active galactic nuclei (AGNs) in models of galaxy evolution, observational constraints on the influence of AGN feedback on star formation remain weak. To this end, we have compared the star formation trends of 279 low-redshift AGN galaxies with 558 inactive control galaxies using integral field unit spectroscopy from the Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory survey. With a Gaussian-process-based methodology, we reconstruct nonparametric star formation histories in spatially resolved spaxels covering the face of each galaxy. Based on the galaxy-wide star formation rates (SFRs) alone, we find no obvious signatures of AGN feedback. However, the AGN galaxies have significantly suppressed central (kiloparsec-scale) SFRs, lying up to a factor of 2 below those of the control galaxies, providing direct observational evidence of AGN feedback suppressing star formation. The suppression of central SFRs in the AGN galaxies began in the central regions ∼6 Gyr ago (redshift z ∼ 0.7), taking place over a few gigayears. A small subset of the AGN galaxies were rapidly driven to quiescence shortly before being observed (in the last 500 Myr), potentially indicating instances of AGN-driven feedback. More frequently, however, star formation continues in the AGN galaxies, with suppression primarily in the central regions. This is suggestive of a picture in which integrated (gigayear-timescale) AGN feedback can significantly affect central star formation, but may be inefficient in driving galaxy-wide quenching in low-redshift galaxies, instead leaving them in the green valley. [ABSTRACT FROM AUTHOR]

Star-formation is one of the main processes that shape galaxies, defining its stellar population and metallicity production and enrichment. It is nowadays known that this process is ruled by a set of relations that connect three parameters: the molecular gas mass, the stellar mass and the star-formation rate itself. These relations are fulfilled at a wide range of scales in galaxies, from galaxy wide to kpc-scales. At which scales they are broken, and how universal they are (i.e., if they change at different scales or for different galaxy types) it is still an open question. We explore here how those relations compare at different scales using as proxy the new analysis done using Integral Field Spectroscopy data and CO observations data from the EDGE-CALIFA survey and the AMUSSING++ compilation. [ABSTRACT FROM AUTHOR]

We study recent changes on the star-formation history (SFH) of galaxies by means of the ageing diagram (AD), tracing the fraction of stars formed during the last ∼20 Myr through the equivalent width of the |$\rm H\alpha$| line and ∼1−3 Gyr through the dust-corrected optical colour (g − r)0or the Balmer break. We provide a physical characterization by using Pipe3D estimates of the SFH of Calar Alto Legacy Integral Field Area and Mapping Nearby Galaxies at Apache Point Observatory galaxies, in combination with the predictions from IllustrisTNG-100. Our results show that the AD may be divided into four domains that correlate with the stellar mass fractions formed in the last 20 Myr and 3 Gyr: ageing systems, whose star formation rate changes on scales of several Gyr, account for |$70-80{{\ \rm per\ cent}}$| of the galaxy population. Objects whose SFH was abruptly truncated in the last ∼1 Gyr arrange along a detached quenched sequence that represents |$\sim 5-10{{\ \rm per\ cent}}$| by (volume-corrected) number for 109 < M */M⊙ < 1012. Undetermined systems represent an intermediate population between the ageing and quenched regimes. Finally, Retired galaxies, dominated by old stellar populations, are located at the region in the AD where the ageing and quenched sequences converge. Defining different star formation activity levels in terms of the birth rate parameter |$b\equiv \frac{SFR}{\langle SFR \rangle }$|⁠ , we find that galaxies transit from the ageing to quenched sequences on scales ∼500 Myr. We conclude that the AD provides a useful tool to discern recently quenched galaxies from the dominant ageing population. [ABSTRACT FROM AUTHOR]

Pristine gas accretion is expected to be the main driver of sustained star formation in galaxies. We measure the required amount of accreted gas at each moment over a galaxy's history to produce the observed metallicity at that time given its star-forming history. More massive galaxies tend to have higher accretion rates and a larger drop of the accretion rate towards the present time. Within the same mass bin galaxies that are currently star-forming or in the Green Valley have similar, sustained, accretion histories while retired galaxies had a steep decline in the past. Plotting the T80 of the individual accretion histories, a measure of how sustained they are, versus the stellar mass and current sSFR we see a distribution such that currently star-forming galaxies have sustained or recent accretion and retired galaxies have declined accretion histories. [ABSTRACT FROM AUTHOR]

The EDGE-CALIFA collaboration has obtained resolved IFU and CO spectroscopy for 126 nearby galaxies, selected from the CALIFA main sample. We have assembled the spatially resolved products of the survey into Astropy-compatible pixel tables that reduce the oversampling in the original FITS images and facilitate comparison of pixels across different images. By joining these pixel tables to lower dimensional tables that provide profiles, integrated spectra, or global properties, it is possible to investigate the dependence of star formation rate on both local and global conditions. In this short video talk I provide an overview of EDGE, with examples of the use of the database to conduct analysis and generate plots. [ABSTRACT FROM AUTHOR]

We utilize the ALMA-MaNGA QUEnch and STar formation (ALMaQUEST) survey to investigate the kpc-scale scaling relations, presented as the resolved star-forming MS (rSFMS: ΣSFR versus Σ*), the resolved Schmidt–Kennicutt relation (rSK: ΣSFR versus), and the resolved molecular gas MS (rMGMS: versus Σ*), for 11,478 star-forming and 1414 retired spaxels (oversampled by a factor of ∼20) located in 22 GV and 12 MS galaxies. For a given galaxy type (MS or GV), the retired spaxels are found to be offset from the sequences formed by the star-forming spaxels on the rSFMS, rSK, and rMGMS planes, toward lower absolute values of sSFR, SFE, and by ∼1.1, 0.6, and 0.5 dex. The scaling relations for GV galaxies are found to be distinct from that of the MS galaxies, even if the analyses are restricted to the star-forming spaxels only. It is found that, for star-forming spaxels, sSFR, SFE, and in GV galaxies are reduced by ∼0.36, 0.14, and 0.21 dex, respectively, compared to those in MS galaxies. Therefore, the suppressed sSFR/SFE/fgas in GV galaxies is associated with not only an increased proportion of retired regions in GV galaxies but also a depletion of these quantities in star-forming regions. Finally, the reduction of SFE and in GV galaxies relative to MS galaxies is seen in both bulge and disk regions (albeit with larger uncertainties), suggesting that, statistically, quenching in the GV population may persist from the inner to the outer regions. [ABSTRACT FROM AUTHOR]

Constraining the delay time distribution (DTD) of different supernova (SN) types can shed light on the time-scales of galaxy chemical enrichment and feedback processes affecting galaxy dynamics, and SN progenitor properties. Here, we present an approach to recover SN DTDs based on integral-field spectroscopy (IFS) of their host galaxies. Using a statistical analysis of a sample of 116 SNe in 102 galaxies, we evaluate different DTD models for SN types Ia (73), II (28), and Ib/c (15). We find the best SN Ia DTD fit to be a power law with an exponent α = −1.1 ± 0.3 (50 per cent confidence interval (C.I.)), and a time delay (between star formation and the first SNe) |$\Delta = 50^{+100}_{-35}~\mathrm{Myr}$| (50 per cent C.I.). For core collapse (CC) SNe, both of the Zapartas et al. DTD models for single and binary stellar evolution are consistent with our results. For SNe II and Ib/c, we find a correlation with a Gaussian DTD model with |$\sigma = 82^{+129}_{-23}~\mathrm{Myr}$| and |$\sigma = 56^{+141}_{-9}~\mathrm{Myr}$| (50 per cent C.I.), respectively. This analysis demonstrates that IFS opens a new way of studying SN DTD models in the local Universe. [ABSTRACT FROM AUTHOR]

The ALMaQUEST (ALMA-MaNGA QUEnching and STar formation) survey is a program with spatially resolved 12CO(1−0) measurements obtained with the Atacama Large Millimeter Array (ALMA) for 46 galaxies selected from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) DR15 optical integral-field spectroscopic survey. The aim of the ALMaQUEST survey is to investigate the dependence of star formation activity on the cold molecular gas content at kiloparsec scales in nearby galaxies. The sample consists of galaxies spanning a wide range in specific star formation rate (sSFR), including starburst (SB), main-sequence (MS), and green valley (GV) galaxies. In this paper, we present the sample selection and characteristics of the ALMA observations and showcase some of the key results enabled by the combination of spatially matched stellar populations and gas measurements. Considering the global (aperture-matched) stellar mass, molecular gas mass, and star formation rate of the sample, we find that the sSFR depends on both the star formation efficiency (SFE) and the molecular gas fraction (), although the correlation with the latter is slightly weaker. Furthermore, the dependence of sSFR on the molecular gas content (SFE or) is stronger than that on either the atomic gas fraction or the molecular-to-atomic gas fraction, albeit with the small H i sample size. On kiloparsec scales, the variations in both SFE and within individual galaxies can be as large as 1–2 dex, thereby demonstrating that the availability of spatially resolved observations is essential to understand the details of both star formation and quenching processes. [ABSTRACT FROM AUTHOR]

The search for new global scaling relations linking the physical properties of galaxies has a fundamental interest. Furthermore, their recovery from spatially resolved relations has been in the spotlight of integral field spectroscopy (IFS). In this study, we investigate the existence of global and local relations between stellar age (Age⋆) and gas-phase metallicity (Zg). To this aim, we analyze IFS data for a sample of 736 star-forming disk galaxies from the MaNGA survey. We report a positive correlation between the global Zg and D(4000) (an indicator of stellar age), with a slope that decreases with increasing galaxy mass. Locally, a similar trend is found when analyzing the Zg and D(4000) of the star-forming regions, as well as the residuals resulting from removing the radial gradients of both parameters. The local laws have systematically smaller slopes than the global one. We ascribe this difference to random errors that cause the true slope of the Age⋆–Zg relation to be systematically underestimated when performing a least-squares fitting. The explored relation is intimately linked with the already known relation between gas metallicity and star formation rate at fixed mass, both presenting a common physical origin. [ABSTRACT FROM AUTHOR]

Galaxies in dense environments, such as groups and clusters, experience various processes by which galaxies gain and lose gas. Using data from the SDSS-IV MaNGA survey, we previously reported the discovery of a giant (6—8 kpc in diameter) Hα blob, Totoro, about 8 kpc away from a pair of galaxies (Satsuki and Mei) residing in a galaxy group that is experiencing a group–group merger. Here, we combine interferometric 12CO(1–0) molecular gas data, new wide-field Hα, u-band data, and published X-ray data to determine the origin of the blob. Several scenarios are discussed to account for its multiwavelength properties, including (1) Hα gas being stripped from the galaxy Satsuki by ram pressure, (2) a separated low-surface-brightness galaxy, (3) gas being ejected or ionized by an active galactic nucleus (AGN), and (4) a cooling intragroup medium (IGM). Scenarios (1) and (2) are less favored by the present data. Scenario (3) is also less likely as there is no evidence for an active ongoing AGN in the host galaxy. We find that the CO (cold) and Hα (warm) gas coexist with X-ray (hot) structures; moreover, the derived cooling time is within the regime where molecular and Hα gas are expected. The coexistence of gas with different temperatures also agrees with that of cooling gas in other systems. Our multiwavelength results strongly suggest that the CO and Hα gas are the product of cooling from the IGM at its current location, i.e., cooling has occurred, and may be ongoing, well outside the host-galaxy core. [ABSTRACT FROM AUTHOR]

Spectral observations of the type-IIb supernova (SN) 2016gkg at 300–800 days are reported. The spectra show nebular characteristics, revealing emission from the progenitor star's metal-rich core and providing clues to the kinematics and physical conditions of the explosion. The nebular spectra are dominated by emission lines of [O i ] λλ6300, 6364 and [Ca ii ] λλ7292, 7324. Other notable, albeit weaker, emission lines include Mg I] λ4571, [Fe ii ] λ7155, O I λ7774, Ca II triplet, and a broad, boxy feature at the location of Hα. Unlike in other stripped-envelope SNe, the [O i ] doublet is clearly resolved due to the presence of strong narrow components. The doublet shows an unprecedented emission line profile consisting of at least three components for each [O i ]λ6300, 6364 line: a broad component (width ∼2000 km s−1), and a pair of narrow blue and red components (width ∼300 km s−1) mirrored against the rest velocity. The narrow component appears also in other lines, and is conspicuous in [O i ]. This indicates the presence of multiple distinct kinematic components of material at low and high velocities. The low-velocity components are likely to be produced by a dense, slow-moving emitting region near the center, while the broad components are emitted over a larger volume. These observations suggest an asymmetric explosion, supporting the idea of two-component ejecta that influence the resulting late-time spectra and light curves. SN 2016gkg thus presents striking evidence for significant asymmetry in a standard-energy SN explosion. The presence of material at low velocity, which is not predicted in 1D simulations, emphasizes the importance of multidimensional explosion modeling of SNe. [ABSTRACT FROM AUTHOR]

I review the spatially resolved spectroscopic properties of low-redshift star-forming galaxies (and their retired counterparts) using results from the most recent optical integral field spectroscopy galaxy surveys. First, I briefly summarize the global spectroscopic properties of these galaxies, discussing the main ionization processes and the global relations described by the star-formation rates, gas-phase oxygen abundances, and average properties of their stellar populations (age and metallicity) in comparison with the stellar mass. Second, I present the local distribution of the ionizing processes down to kiloparsec scales, and I show how the global scaling relations found using integrated parameters (like the star-formation main sequence, mass–metallicity relation, and Schmidt–Kennicutt law) have local/resolved counterparts, with the global ones being, for the most part, just integrated/average versions of the local ones. I discuss the local/resolved star-formation histories (SFHs) and chemical-enrichment histories and their implications on the inside-out growth of galaxies. Third, I present the radial distributions of the surface densities of the properties explored globally and how they depend on the integrated galaxy properties. In conclusion, I find that the evolution of galaxies is mostly governed by local processes but clearly affected by global ones: Many global scaling relations present resolved counterparts (verified down to kiloparsec scales) that can explain them as well as the observed radial gradients in galaxies. These relations are consequences of the local SFHs, the narrow range of the depletion times, and a local metal enrichment. Deviations from these relations are due to dynamical and mixing processes, local exchange of gas (inflows, outflows, and fountains), depletion time differences, and/or differences in the resolved SFHs. Ionization happens at local scales that may be driven by different physical processes, and it cannot be clearly understood using purely integrated quantities. The dominant ionization in galaxies has a stellar origin. [ABSTRACT FROM AUTHOR]

Spiral arms are the most characteristic features of disc galaxies, easily distinguishable due to their association with ongoing star formation. However, the role of spiral structure in the chemical evolution of galaxies is unclear. Here, we explore gas-phase abundance variations between arm and interarm regions for a sample of 45 spiral galaxies using high spatial resolution VLT/MUSE integral field spectroscopy data. We report the presence of more metal-rich |$\rm{H \, \small{II}}$| regions in the spiral arms with respect to the corresponding interarm regions for a large subsample of galaxies (⁠|$45\!-\!65{{\ \rm per\ cent}}$| depending on the adopted calibrator for the abundance derivation). A small percentage of the sample is observed to display the opposite trend, i.e. more metal-poor |$\rm{H \, \small{II}}$| regions in the spiral arms compared to that of the interarms (⁠|$5\!-\!20{{\ \rm per\ cent}}$| depending on the calibrator). We investigate the dependence of the variations with three galaxy properties: the stellar mass, the presence of bars, and the flocculent/grand design appearance of spiral arms. In all cases, we observe that the arm–interarm abundance differences are larger (positive) in more massive and grand-design galaxies. This is confirmed by an analogous spaxel-wise analysis, which also shows a noticeable effect of the presence of galactic bars, with barred systems presenting larger (positive) arm–interarm abundance variations than unbarred systems. The comparison of our results with new predictions from theoretical models exploring the nature of the spirals would highly impact on our knowledge on how these structures form and affect their host galaxies. [ABSTRACT FROM AUTHOR]

We study the presence of optically-selected active galactic nuclei (AGNs) within a sample of 867 galaxies extracted from the extended Calar-Alto Legacy Integral Field spectroscopy Area (eCALIFA) spanning all morphological classes. We identify 10 Type-I and 24 Type-II AGNs, amounting to ∼4 per cent of our sample, similar to the fraction reported by previous explorations in the same redshift range. We compare the integrated properties of the ionized and molecular gas, and stellar population of AGN hosts and their non-active counterparts, combining them with morphological information. The AGN hosts are found in transitory parts (i.e. green-valley) in almost all analysed properties which present bimodal distributions (i.e. a region where reside star-forming galaxies and another with quiescent/retired ones). Regarding morphology, we find AGN hosts among the most massive galaxies, with enhanced central stellar-mass surface density in comparison to the average population at each morphological type. Moreover, their distribution peaks at the Sab-Sb classes and none are found among very late-type galaxies (>Scd). Finally, we inspect how the AGN could act in their hosts regarding the quenching of star-formation. The main role of the AGN in the quenching process appears to be the removal (or heating) of molecular gas, rather than an additional suppression of the already observed decrease of the star-formation efficiency from late-to-early type galaxies. [ABSTRACT FROM AUTHOR]

We present an empirical relation between the cold gas surface density (Σgas) and the optical extinction (AV) in a sample of 103 galaxies from the Extragalactic Database for Galaxy Evolution (EDGE) survey. This survey provides CARMA interferometric CO observations for 126 galaxies included in the Calar Alto Legacy Integral Field Area (CALIFA) survey. The matched, spatially resolved nature of these data sets allows us to derive the Σgas– AV  relation on global, radial, and kpc (spaxel) scales. We determine AV  from the Balmer decrement (H α/H β). We find that the best fit for this relation is |$\Sigma _{\rm gas}\,(\rm {M_\odot \,pc}^{-2}) \sim 26 \times {\rm \mathit{ A}_\mathit{ V}} \,(\rm mag)$|⁠ , and that it does not depend on the spatial scale used for the fit. However, the scatter in the fits increases as we probe smaller spatial scales, reflecting the complex relative spatial distributions of stars, gas, and dust. We investigate the Σgas/ AV  ratio on radial and spaxel scales as a function of |$\mathrm{EW(H\,\alpha)}$|⁠. We find that at larger values of |$\mathrm{EW({H\,\alpha })}$| (i.e. actively star-forming regions) this ratio tends to converge to twice the value expected for a foreground dust screen geometry (∼30 |$\mathrm{M_{\odot } \, pc^{-2} \, mag^{-1}}$|⁠). On radial scales, we do not find a significant relation between the Σgas/ AV  ratio and the ionized gas metallicity. We contrast our estimates of Σgas using AV  with compilations in the literature of the gas fraction on global and radial scales as well as with well-known scaling relations such as the radial star formation law and the Σgas–Σ* relation. These tests show that optical extinction is a reliable proxy for estimating Σgas in the absence of direct sub/millimeter observations of the cold gas. [ABSTRACT FROM AUTHOR]

By means of post-processed cosmological hydrodynamics simulations, we explore the ability of the fossil record method to recover the stellar mass, age gradients, and global/radial star formation and mass growth histories of galaxies observed with an optical Integral Field Unity (IFU). We use two simulations of representative Milky Way-sized galaxies, one disc-dominated and another bulge-dominated. We generate data cubes emulating MaNGA/SDSS-IV instrumental and observational conditions, and analyze them using the Pipe3D pipeline. For optimal MaNGA instrumental/observational set-ups, the global masses, ages, and dust extinctions of both galaxies are well recovered within the uncertainties, while for the radial distributions, the trend is to get slightly flatter age gradients and weaker inside-out growth modes than the true ones. The main bias is in recovering younger stellar populations in the inner, older regions, and slightly older stellar populations in the outer, younger regions, as well as lower global stellar masses. These trends are enhanced as lower is the spatial sampling/resolution (less number of fibres), more inclined and dust-attenuated is the observed galaxy, lower is the signal-to-noise ratio, and worse is the seeing. The recovered properties and histories are more affected for the disc-dominated galaxy with a prominent inside-out growth mode than for the bulge-dominated galaxy assembled earlier and more coherently. We make publicly available the code and the mock IFU datacubes used in this paper. [ABSTRACT FROM AUTHOR]

We present a sample of 17 objects from the CALIFA survey where we find initial evidence of galactic winds based on their off-axis ionization properties. We identify the presence of outflows using various optical diagnostic diagrams [e.g. EW(H α), [N  ii ]/H α, [S  ii ]/H α, [O  i ]/H α line-ratio maps]. We find that all 17 candidate outflow galaxies lie along the sequence of active star formation in the M⋆ versus star-formation rate (SFR) diagram, without a clear excess in the integrated SFR. The location of galaxies along the star-formation main sequence does not influence strongly the presence or not of outflows. The analysis of the SFR density (ΣSFR) reveals that the CALIFA sources present higher values when compared with normal star-forming galaxies. The strength of this relation depends on the calibrator used to estimate the SFR. This excess in ΣSFR is significant within the first effective radius supporting the idea that most outflows are driven by processes in the inner regions of a galaxy. We find that the molecular gas mass density (Σgas) is a key parameter that plays an important role in the generation of outflows through its association with the local SFR. The canonical threshold reported for the generation of outflows – ΣSFR > 0.1 |$\mathrm{M}_\odot \, \mathrm{yr}^{-1} \, \mathrm{kpc}^{-2}$| – is only marginally exceeded in our sample. Within the Kennicutt–Schmidt diagram we propose a domain for galaxies hosting starburst-driven outflows defined by |$\Sigma _{\rm SFR}\gt 10^{-2} \, \mathrm{M}_\odot \, \mathrm{yr}^{-1} \, \mathrm{kpc}^{-2}$| and |$\Sigma _\mathrm{gas}\gt 10^{1.2} \, \, \mathrm{M}_\odot \, \mathrm{pc}^{-2}$| within a central kiloparsec region. [ABSTRACT FROM AUTHOR]

Negative feedback from accretion on to supermassive black holes (SMBHs), that is to remove gas and suppress star formation in galaxies, has been widely suggested. However, for Seyfert galaxies which harbour less active, moderately accreting SMBHs in the local Universe, the feedback capability of their black hole activity is elusive. We present spatially resolved H  α measurements to trace ongoing star formation in Seyfert galaxies and compare their specific star formation rate with a sample of star-forming galaxies whose global galaxy properties are controlled to be the same as the Seyferts. From the comparison, we find that the star formation rates within central kpc of Seyfert galaxies are mildly suppressed as compared to the matched normal star-forming galaxies. This suggests that the feedback of moderate SMBH accretion could, to some extent, regulate the ongoing star formation in these intermediate to late type galaxies under secular evolution. [ABSTRACT FROM AUTHOR]

Using the fossil record method implemented through Pipe3D, we reconstruct the global and radial stellar mass growth histories (MGHs) of a large sample of galaxies, ranging from dwarf to giant objects, from the Mapping Nearby Galaxies at the Apache Point Observatory (MaNGA) survey. We confirm that the main driver of the global MGHs is mass, with more massive galaxies assembling earlier (downsizing), though for a given mass, the global MGHs segregate by colour, specific star formation rate and morphological type. From the inferred radial mean MGHs, we find that at fractions of assembled mass larger than ~80 per cent, the innermost regions formed stars, on average, in the inside-out mode. At earlier epochs, when the age estimation of the method becomes poor, the MGHs seem to be spatially homogeneous or even in the outside-in mode, especially for the red/quiescent/early-type galaxies. The innermost MGHs are, in general, less scattered around the mean than the outermost MGHs. For dwarf and low-mass galaxies, we do not find evidence of an outside-in formation mode; instead, their radial MGHs are very diverse most of the time, with periods of outside-in and inside-out modes (or strong radial migration), suggesting this is an episodic star formation history. Blue/starforming/ late-type galaxies present, on average, a significantly more pronounced inside-out formation mode than red/quiescent/early-type galaxies, independently of mass. We discuss our results in the light of the processes of galaxy formation, quenching and radial migration. We also discuss the uncertainties and biases of the fossil record method and how these could affect our results. [ABSTRACT FROM AUTHOR]

We investigate the spiral galaxy NGC 5394, which is strongly interacting with the larger spiral NGC 5395 (the pair is Arp 84), using optical integral-field spectroscopy from the CALIFA (Calar Alto Legacy Integral Field Area) survey. Spatially resolved equivalent widths, emissionline ratios and kinematics reveal many features related to the interaction, which has reshaped the galaxy. Ha maps (with other diagnostic emission lines) showa concentrated central (r<1 kpc) starburst and three less luminous star-forming regions (one knot far out in the northern arm), and we estimate the dust-corrected total star-formation rate as 3.39 M⊙ yr-1. However, much of the galaxy, especially the outer tidal arms, has a post-starburst spectrum, evidence of a more extensive episode of star formation a few × 108 yr ago, triggered by the previous perigalacticon. The [NII]6584/Hα ratio is high in the nucleus, reaching 0.63 at the centre, which we interpret as related to high electron density (ne ≃ 750 cm-3 from the [S II] 67316717 ratio). We find a central region of strong and blueshifted Na I(5890,5896) absorption, indicative of a starburst-driven outflow from the nucleus at an estimated velocity ~223 km s-1. The CALIFA data also show an annular region at radii 2.25-4 kpc from the nucleus, with elevated ratios of [N II], [O I]6300 etc. to the Balmer lines - this is evidence of shock excitation, which might be the result of interaction-triggered gas inflow. [ABSTRACT FROM AUTHOR]

We present here a brief summary of the currenly on-going IFU surveys of galaxies in teh Local Universe, describing their main characteristics, including their sample selections, instrumental setups, wavelength ranges, and area of the galaxies covered. Finally, we make an emphasis on the main characteristics of the CALIFA survey and the more recent results that has been recently published. [ABSTRACT FROM PUBLISHER]

ABSTRACT Numerical simulations of minor mergers, typically having mass ratios greater than 3:1, predict little enhancement in the global star formation activity. However, these models also predict that the satellite galaxy is more susceptible to the effects of the interaction than the primary. We use optical integral field spectroscopy and deep optical imaging to study the NGC 7771+NGC 7770 interacting system (∼10:1 stellar mass ratio) to test these predictions. We find that the satellite galaxy NGC 7770 is currently experiencing a galaxy-wide starburst with most of the optical light being from young and post-starburst stellar populations (<1 Gyr). This galaxy lies off the local star-forming sequence for composite galaxies with an enhanced integrated specific star formation rate. We also detect in the outskirts of NGC 7770 Hα emitting gas filaments. This gas appears to have been stripped from one of the two galaxies and is being excited by shocks. All these results are consistent with a minor-merger-induced episode(s) of star formation in NGC 7770 after the first close passage. Such effects are not observed on the primary galaxy NGC 7771. [ABSTRACT FROM AUTHOR]

Using integral field spectroscopy (IFS) we have observed QSOs which were previously known to have intervening DLAs, to search for emission lines in the field surrounding the QSOs. The sample consists of 13 DLAs plus 7 sub-DLAs at $z>2$, from which we find emission line candidates at the expected wavelengths for 8 systems, implying a detection frequency of 40%. Emission lines detected at the DLA redshifts are interpreted as being due to Ly$\alpha$ lines from galaxies associated with the DLA clouds. Candidates are detected at $3-4\sigma$ levels in both narrow-band images and spectra created from the data cubes. We find no preference for candidate detection associated with either high or low metallicity DLAs. In comparison with the properties of previously known DLA galaxies, the candidates show similar distributions of line fluxes and line widths, but their impact parameters are slightly different, suggesting H I cross sections larger than 10 kpc. [ABSTRACT FROM PUBLISHER]

This study has been published in Sánchez-Menguiano et al. (2018). We encourage the reader to that article for more details on the study and the results. [ABSTRACT FROM AUTHOR]

Truncations in the stellar population at the edges of disk galaxies are thought to be a common morphological feature (e.g., Erwin et al. 2005; and more recently Marino et al. 2016). In fact, using imaging data from the SDSS, Pohlen & Trujillo (2006) showed that only ~ 10% of face-on to intermediate inclined, nearby, late-type (Sb-Sdm) spiral galaxies have a normal/standard purely exponential disk down to the noise limit. In situations like these, the simultaneous fit of two lines, joined or not at an intermediate point (the break radius), constitutes a natural step towards the modelling of radial variation in surface brightness, metallicity, or any other relevant parameter. This work shows the results of simple simulations in which the simultaneous fit to two joined lines is compared to the simultaneous fit of two independent lines (i.e., two lines that do not necessarily coincide at an intermediate point), and also to the traditional single ordinary least squares fit. These simulations reveal some biases that should be taken into account when facing these kind of fitting procedures. [ABSTRACT FROM PUBLISHER]

Recent theoretical and observational works claim the existence of galaxies with a characteristic age profile consisting on a negative radial trend followed by a smooth age upturn in its outskirts (“U-shape”). This shape has been generally related to down-bending light distributions; however, the existence of a real link between observed Surface Brightness (SB) profiles and changes in stellar properties such as age is still unclear. [ABSTRACT FROM PUBLISHER]

The study of the star formation rate (SFR) is crucial for understanding the birth and evolution of the galaxies (Kennicutt 1998), with this aim in mind, we make use of a well-characterized sample of 380 nearby galaxies from the CALIFA survey that fill the entire color-magnitude diagram in the Local Universe. The availability of wide-field CALIFA IFS ensures a proper determination of the underlying stellar continuum and, consequently, of the extiction-corrected Hα luminosity. We compare our integrated Hα-based SFRs with single and hybrids tracers at other wavelengths found in the literature (Calzetti 2013). Then, we provide a new set of single-band and hybrid calibrators anchored to the extinction-corrected Hα luminosities. In the case of the hybrid calibrators we determine the best fitting aIR coefficients for different combinations of observed (UV or Hα) and dust-reprocessed (22μm or TIR) SFR contributions (where SFR ∝ Lobs + aIR × L[IR]). This analysis allow us to provide, for the first time, a set of hybrid calibrations for different morphological types and masses. These are particularly useful in case that the sample to be analyzed shows a different bias in terms of morphology or, more commonly, luminosity or stellar mass. We also study the dependence of this coefficient with color and ionized-gas attenuation. The distributions of aIR values are quite wide in all cases. We found that not single physical property can by itself explain the variation found in aIR.Finally, we explore the spatial distribution of the SFR by measuring the contribution of disks to the total SFR in the Local Universe. Our preliminary spatially-resolved analysis shows that the disk to total (disk + spheroidal component) SFR ratio is on average ∼ 88%. The use of the 2D spectroscopic data is critical to properly determine the Hα luminosity function and SFR density in the Local Universe per galaxy components, the ultimate goal of this project. [ABSTRACT FROM PUBLISHER]