Marie Martig

• Max Planck Institute for Astronomy

We trace the evolution of eight edge-on star-forming disk galaxies by analyzing stellar population properties of their thin and thick disks. These galaxies have relatively low stellar masses (4 times 10^9 to 6 times 10^10 M_⊙). We used Multi-Unit Spectroscopic Explorer (MUSE) observations and a full-spectrum fitting to produce spatially resolved ma...

We aim to trace the evolution of eight edge-on star-forming disc galaxies through the analysis of stellar population properties of their thin and thick discs. These galaxies have relatively low stellar masses (4 $\times$ 10$^9$ to 6 $\times$ 10$^{10}$ $M_{\odot}$). We use Multi-Unit Spectroscopic Explorer (MUSE) observations and full-spectrum fitti...

The well-known bimodal distribution of Milky Way disk stars in the alpha /Fe --metallicity plane is often used to define thick and thin disks. In external edge-on galaxies, there have been attempts to identify this type of bimodality using integral field spectroscopy (IFS) data. However, for unresolved stellar populations, observations only contain...

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...

We assessed the ability to recover chemical bimodalities in integral-field spectroscopy (IFS) observations of edge-on galaxies, using 24 Milky Way-mass galaxies from the AURIGA zoom-in cosmological simulations. We first analyzed the distribution of single stellar particles in the [Mg/Fe] - [Fe/H] plane. Then we produced mock IFS [Mg/Fe] and [Fe/H]...

The Milky Way’s last significant merger, the Gaia Enceladus/Sausage (GES), is thought to have taken place between 8–11 Gyr ago. Recent studies in the literature suggest that the bar of the Milky Way is rather old, indicating that it formed at a similar epoch to the GES merger. We investigate the possible link between these events using one of the A...

We use numerical simulations to model Gaia DR3 data with the aim of constraining the Milky Way (MW) bar and spiral structure parameters. We show that both the morphology and the velocity field in MW-like galactic disc models are strong functions of time, changing dramatically over a few tens of Myr. This suggests that by finding a good match to the...

Context. Recent integral-field spectroscopy observations of edge-on galaxies have led to significant progress in our knowledge of the ages and chemical compositions of thick disks. However, the origin of thick disks and their evolutionary connection with thin disks is still a matter of debate. Aims. We provide new insights into this topic by connec...

We trace the evolution of the edge-on spiral galaxy NGC 3501, making use of its stellar populations extracted from deep integral-field spectroscopy MUSE observations. We present stellar kinematic and population maps, as well as the star formation history, of the south-western half of the galaxy. The derived maps of the stellar line-of-sight velocit...

We trace the evolution of the edge-on spiral galaxy NGC 3501, making use of its stellar populations extracted from deep integral-field spectroscopy MUSE observations. We present stellar kinematic and population maps, as well as the star formation history, of the south-western half of the galaxy. The derived maps of the stellar line-of-sight velocit...

Warps are observed in a large fraction of disc galaxies, and can be due to a large number of different processes. Some of these processes might also cause vertical heating and flaring. Using a sample of galaxies simulated in their cosmological context, we study the connection between warping and disc heating. We analyse the vertical stellar density...

Observations and simulations of interacting galaxies and mergers in the local universe have shown that interactions can significantly enhance the star formation rates (SFRs) and fueling of active galactic nuclei (AGN). However, at higher redshift, some simulations suggest that the level of star formation enhancement induced by interactions is lower...

The epoch in which galactic discs settle is a major benchmark to test models of galaxy formation and evolution but is as yet largely unknown. Once discs settle and become self-gravitating enough, stellar bars are able to form; therefore, determining the ages of bars can shed light on the epoch of disc settling, and on the onset of secular evolution...

Observations and simulations of interacting galaxies and mergers in the local universe have shown that interactions can significantly enhance the star formation rates (SFR) and fueling of Active Galactic Nuclei (AGN). However, at higher redshift, some simulations suggest that the level of star formation enhancement induced by interactions is lower...

Theoretical works have shown that off-plane motions of bars can heat stars in the vertical direction during buckling but is not clear how do they affect the rest of components of the Stellar Velocity Ellipsoid (SVE). We study the 2D spatial distribution of the vertical, σz, azimuthal, σφ and radial, σr velocity dispersions in the inner regions of A...

Theoretical works have shown that off-plane motions of bars can heat stars in the vertical direction during buckling but is not clear how do they affect the rest of components of the Stellar Velocity Ellipsoid (SVE). We study the 2D spatial distribution of the vertical, $\sigma_{z}$, azimuthal, $\sigma_{\phi}$ and radial, $\sigma_{r}$ velocity disp...

The mass function of globular cluster (GC) populations is a fundamental observable that encodes the physical conditions under which these massive stellar clusters formed and evolved. The high-mass end of star cluster mass functions are commonly described using a Schechter function, with an exponential truncation mass Mc, *. For the GC mass function...

Warps are observed in a large fraction of disc galaxies, and can be due to a large number of different processes. Some of these processes might also cause vertical heating and flaring. Using a sample of galaxies simulated in their cosmological context, we study the connection between warping and disc heating. We analyse the vertical stellar density...

The existence of massive galaxies lacking a classical bulge has often been proposed as a challenge to ΛCDM. However, recent simulations propose that a fraction of massive disc galaxies might have had very quiescent merger histories, and also that mergers do not necessarily build classical bulges. We test these ideas with deep MUSE observations of N...

The existence of massive galaxies lacking a classical bulge has often been proposed as a challenge to $\Lambda$CDM. However, recent simulations propose that a fraction of massive disc galaxies might have had very quiescent merger histories, and also that mergers do not necessarily build classical bulges. We test these ideas with deep MUSE observati...

The connection between the Stellar Velocity Ellipsoid (SVE) and the dynamical evolution of galaxies has been a matter of debate in the last years and there is no clear consensus whether different heating agents (e.g. spiral arms, giant molecular clouds, bars and mergers) leave clear detectable signatures in the present day kinematics. Most of these...

The connection between the Stellar Velocity Ellipsoid (SVE) and the dynamical evolution of galaxies has been a matter of debate in the last years and there is no clear consensus whether different heating agents (e.g. spiral arms, giant molecular clouds, bars and mergers) leave clear detectable signatures in the present day kinematics. Most of these...

The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning w...

Dynamical models allow us to connect the motion of a set of tracers to the underlying gravitational potential, and thus to the total (luminous and dark) matter distribution. They are particularly useful for understanding the mass and spatial distribution of dark matter (DM) in a galaxy. Globular clusters (GCs) are an ideal tracer population in dyna...

Dynamical models allow us to connect the motion of a set of tracers to the underlying gravitational potential, and thus to the total (luminous and dark) matter distribution. They are particularly useful for understanding the mass and spatial distribution of dark matter (DM) in a galaxy. Globular clusters (GCs) are an ideal tracer population in dyna...

Using simulated galaxies in their cosmological context, we analyse how the flaring of mono-age populations (MAPs) influences the flaring and the age structure of geometrically-defined thick discs. We also explore under which circumstances the geometric thin and thick discs are meaningfully distinct components, or are part of a single continuous str...

We introduce BAYES-LOSVD, a novel implementation of the non-parametric extraction of line-of-sight velocity distributions (LOSVDs) in galaxies. We employed Bayesian inference to obtain robust LOSVDs and associated uncertainties. Our method relies on a principal component analysis to reduce the dimensionality on the set of templates required for the...

Using simulated galaxies in their cosmological context, we analyse how the flaring of mono-age populations (MAPs) influences the flaring and the age structure of geometrically-defined thick discs. We also explore under which circumstances the geometric thin and thick discs are meaningfully distinct components, or are part of a single continuous str...

Galaxy interactions and mergers are thought to play an important role in the evolution of galaxies. Studies in the nearby universe show a higher fraction of active galactic nuclei (AGNs) in interacting and merging galaxies than in their isolated counterparts, indicating that such interactions are important contributors to black hole growth. To inve...

The central regions of disc galaxies hold clues to the processes that dominate their formation and evolution. To exploit this, the TIMER project has obtained high signal-to-noise and spatial resolution integral-field spectroscopy data of the inner few kpc of 21 nearby massive barred galaxies, which allows studies of the stellar kinematics in their...

Context. Studying the stellar kinematics of galaxies is a key tool in the reconstruction of their evolution. However, the current measurements of the stellar kinematics are complicated by several factors, including dust extinction and the presence of multiple stellar populations. Aims. We use integral field spectroscopic data of four galaxies from...

Studying the stellar kinematics of galaxies is a key tool in the reconstruction of their evolution. However, the current measurements of the stellar kinematics are complicated by several factors, including dust extinction and the presence of multiple stellar populations. We use integral field spectroscopic data of four galaxies from the TIMER surve...

Galaxy interactions and mergers are thought to play an important role in the evolution of galaxies. Studies in the nearby universe show a higher AGN fraction in interacting and merging galaxies than their isolated counterparts, indicating that such interactions are important contributors to black hole growth. To investigate the evolution of this ro...

The central regions of disc galaxies hold clues to the processes that dominate their formation and evolution. The TIMER project has obtained high signal-to-noise and spatial resolution integral-field spectroscopy data of the inner few kpc of 21 nearby massive barred galaxies, allowing studies of the stellar kinematics with unprecedented spatial res...

The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exists a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning...

Stellar populations in barred galaxies save an imprint of the influence of the bar on the host galaxy’s evolution. We present a detailed analysis of star formation histories (SFHs) and chemical enrichment of stellar populations in nine nearby barred galaxies from the TIMER project. We used integral field observations with the MUSE instrument to der...

Stellar populations in barred galaxies save an imprint of the influence of the bar on the host galaxy's evolution. We present a detailed analysis of star formation histories (SFHs) and chemical enrichment of stellar populations in nine nearby barred galaxies from the TIMER project. We use integral field observations with the MUSE instrument to deri...

We study the late-time evolution of the central regions of two Milky Way-like galaxies formed in a cosmological context, one hosting a fast bar and the other a slow one. We find that bar length, R_b, measurements fluctuate on a dynamical timescale by up to 100%, depending on the spiral structure strength and measurement threshold. The bar amplitude...

The α-element abundances of the globular cluster (GC) and field star populations of galaxies encode information about the formation of each of these components. We use the E-MOSAICS cosmological simulations of ∼L* galaxies and their GCs to investigate the [α/Fe]–[Fe/H] distribution of field stars and GCs in 25 Milky Way–mass galaxies. The [α/Fe]–[F...

The kinematics of the Milky Way disc as a function of age are well measured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-[Fe/H] populations in the low and high [α/Fe] discs between 4 ≲ R ≲ 13 kpc and |z| ≲ 2 kpc using 65 719 stars in common between APOGE...

Stellar feedback plays a significant role in modulating star formation, redistributing metals, and shaping the baryonic and dark structure of galaxies – however, the efficiency of its energy deposition to the interstellar medium is challenging to constrain observationally. Here we leverage HST and ALMA imaging of a molecular gas and dust shell ($M_...

Several deep observations such as those carried out at the Canada-France-Hawaii Telescope (CFHT) have revealed prominent Low Surface Brightness (LSB) fine structures that change the apparent morphology of galaxies. Previous photometry surveys have developed observational techniques which exploit the diffuse light detected in the external regions of...

Several deep observations such as those carried out at the Canada-France-Hawaii Telescope (CFHT) have revealed prominent Low Surface Brightness (LSB) fine structures that change the apparent morphology of galaxies. Previous photometry surveys have developed observational techniques which exploit the diffuse light detected in the external regions of...

Stellar feedback plays a significant role in modulating star formation, redistributing metals, and shaping the baryonic and dark structure of galaxies -- however, the efficiency of its energy deposition to the interstellar medium is challenging to constrain observationally. Here we leverage HST and ALMA imaging of a molecular gas and dust shell ($M...

Context . Galactic disc chemical evolution models generally ignore azimuthal surface density variation that can introduce chemical abundance azimuthal gradients. Recent observations, however, have revealed chemical abundance changes with azimuth in the gas and stellar components of both the Milky Way and external galaxies. Aims . Our aim is to quan...

We have used deep MUSE observations to perform a stellar-kinematic and population analysis of FCC 153 and FCC 177, two edge-on S0 galaxies in the Fornax cluster. The geometrical definition of the different structural components of these two galaxies allows us to describe the nature of their thick disks. These are both old, relatively metal poor and...

We used deep MUSE observations to perform a stellar-kinematic and population analysis of FCC 153 and FCC 177, two edge-on S0 galaxies in the Fornax cluster. The geometrical definition of the different structural components of these two galaxies allows us to describe the nature of their thick disks. These are both old, relatively metal poor and [Mg/...

We use Gaia DR2 astrometric and line-of-sight velocity information combined with two sets of distances obtained with a Bayesian inference method to study the 3D velocity distribution in the Milky Way disc. We search for variations in all Galactocentric cylindrical velocity components ($V_{\phi}$, $V_R$ and $V_z$) with Galactic radius, azimuth, and...

Simpson's paradox, or the Yule-Simpson effect, arises when a trend appears in different subsets of data but disappears or reverses when these subsets are combined. We describe here seven cases of this phenomenon for chemo-kinematical relations believed to constrain the Milky Way disk formation and evolution. We show that interpreting trends in rela...

We present and discuss the stellar kinematics and populations of the S0 galaxy FCC 170 (NGC 1381) in the Fornax cluster, using deep MUSE data from the Fornax 3D survey. We show the maps of the first four moments of the stellar line-of-sight velocity distribution and of the mass-weighted mean stellar age, metallicity, and [Mg/Fe] abundance ratio. Th...

We present and discuss the stellar kinematics and populations of the S0 galaxy FCC 170 (NGC 1381) in the Fornax cluster, using deep MUSE data from the Fornax 3D survey. We show the maps of the first four moments of the stellar line-of-sight velocity distribution and of the mass-weighted mean stellar age, metallicity and [Mg/Fe] abundance ratio. The...

The kinematics of the Milky Way disc as a function of age are well measured at the solar radius, but have not been studied over a wider range of Galactocentric radii. Here, we measure the kinematics of mono-age, mono-$\mathrm{[Fe/H]}$ populations in the low and high $\mathrm{[\alpha/Fe]}$ discs between $4 \lesssim R \lesssim 13$ kpc and $|z| \lesss...

The Time Inference with MUSE in Extragalactic Rings (TIMER) project is a survey with the VLT-MUSE integral-field spectrograph of 24 nearby barred galaxies with prominent central structures (e.g. nuclear rings or inner discs). The main goals of the project are: (i) estimating the cosmic epoch when discs of galaxies settle, leading to the formation o...

Galactic disc chemical evolution models generally ignore azimuthal surface density variation that can introduce chemical abundance azimuthal gradients. Recent observations, however, have revealed chemical abundance changes with azimuth in the gas and stellar components of both the Milky Way and external galaxies.To quantify the effects of spiral ar...

One of the fundamental assumptions of chemical evolution models (CEMs) of the Milky Way (MW) and other spirals is that higher gas accretion rates are expected in the past, and in the inner regions of the Galaxy. This leads to the so-called ‘inside-out disc formation scenario’. Yet, these are probably the most unconstrained inputs of such models. In...

The Time Inference with MUSE in Extragalactic Rings (TIMER) project is a survey with the VLT-MUSE integral-field spectrograph of 24 nearby barred galaxies with prominent central structures (e.g., nuclear rings or inner discs). The main goals of the project are: (i) estimating the cosmic epoch when discs of galaxies settle, leading to the formation...

One of the fundamental assumptions of chemical evolution models (CEMs) of the Milky Way (MW) and other spirals is that higher gas accretion rates are expected in the past, and in the inner regions of the Galaxy. This leads to the so-called "inside-out disc formation scenario". Yet, these are probably the most unconstrained inputs of such models. In...

In chemodynamical evolution models it is usually assumed that the Milky Way galaxy forms from the inside-out implying that gas inflows onto the disk decrease with galactocentric distance. Similarly, to reproduce differences between chemical abundances of the thick disk and bulge with respect to those of the thin disk, higher accretion fluxes at ear...

We present a semi-empirical, largely model-independent approach for estimating Galactic birth radii, r_birth, for Milky Way disk stars. The technique relies on the justifiable assumption that a negative radial metallicity gradient in the interstellar medium (ISM) existed for most of the disk lifetime. Stars are projected back to their birth positio...

We present a semi-empirical, largely model-independent approach for estimating Galactic birth radii, r_birth, for Milky Way disk stars. The technique relies on the justifiable assumption that a negative radial metallicity gradient in the interstellar medium (ISM) existed for most of the disk lifetime. Stars are projected back to their birth positio...

Galaxy formation entails the hierarchical assembly of mass, along with the condensation of baryons and the ensuing, self-regulating star formation. The stars form a collisionless system whose orbit distribution retains dynamical memory that can constrain a galaxy's formation history. The ordered-rotation dominated orbits with near maximum circulari...

Early-type galaxies (ETGs) contain most of the stars present in the local Universe and, above a stellar mass content of ~5 × 1010 solar masses, vastly outnumber spiral galaxies such as the Milky Way. These massive spheroidal galaxies have, in the present day, very little gas or dust in proportion to their mass1, and their stellar populations have b...

The stellar velocity ellipsoid (SVE) in galaxies can provide important information on the processes that participate in the dynamical heating of their disc components (e.g. giant molecular clouds, mergers, spiral density waves, bars). Earlier findings suggested a strong relation between the shape of the disc SVE and Hubble type, with later-type gal...

Galaxy formation entails the hierarchical assembly of mass, along with the condensation of baryons and the ensuing, self-regulating star formation. The stars form a collisionless system whose orbit distribution retains dynamical memory that can constrain a galaxy's formation history. The ordered-rotation dominated orbits with near maximum circulari...

We analyze age-velocity dispersion relations (AVRs) from kinematics of individual stars in eight Local Group galaxies ranging in mass from Carina ($M_{*} \sim 10^{6}$) to M31 ($M_{*} \sim 10^{11}$). Observationally the $\sigma$ vs. stellar age trends can be interpreted as dynamical heating of the stars by GMCs, bars/spiral arms, or merging subhalos...

The radial profiles of stars in disc galaxies are observed to be either purely exponential (Type-I), truncated (Type-II) or antitruncated (Type-III) exponentials. Controlled formation simulations of isolated galaxies can reproduce all of these profile types by varying a single parameter, the initial halo spin. In this paper, we examine these simula...

Schwarzschild orbit-based dynamical models are widely used to uncover the internal dynamics of early-type galaxies and globular clusters. Here we present for the first time the Schwarzschild models of late-type galaxies: an SBb galaxy NGC 4210 and an S0 galaxy NGC 6278 from the CALIFA survey. The mass profiles within $2\,R_e$ are constrained well w...

In chemodynamical evolution models it is usually assumed that the Milky Way galaxy forms from the inside-out implying that gas inflows onto the disk decrease with galactocentric distance. Similarly, to reproduce differences between chemical abundances of the thick disk and bulge with respect to those of the thin disk, higher accretion fluxes at ear...

Deciphering the assembly history of the Milky Way is a formidable task, which becomes possible only if one can produce high-resolution chrono-chemo-kinematical maps of the Galaxy. Data from large-scale astrometric and spectroscopic surveys will soon provide us with a well-defined view of the current chemo-kinematical structure of the Milky Way, but...

Early type galaxies (ETG) contain most of the stars present in the local Universe and, above a stellar mass of ~5e10 Msun, vastly outnumber spiral galaxies like the Milky Way. These massive spheroidal galaxies have, in the present day, very little gas or dust, and their stellar populations have been evolving passively for over 10 billion years. The...

In the Milky Way, the thick disk can be defined using individual stellar abundances, kinematics, or age; or geometrically, as stars high above the mid-plane. In nearby galaxies, where only a geometric definition can be used, thick disks appear to have large radial scale-lengths, and their red colors suggest that they are uniformly old. The Milky Wa...

In the Milky Way, the thick disk can be defined using individual stellar abundances, kinematics, or age; or geometrically, as stars high above the mid-plane. In nearby galaxies, where only a geometric definition can be used, thick disks appear to have large radial scale-lengths, and their red colors suggest that they are uniformly old. The Milky Wa...

Studying the Milky Way disk structure using stars in narrow bins of [Fe/H] and [alpha/Fe] has recently been proposed as a powerful method to understand the Galactic thick and thin disk formation. It has been assumed so far that these mono-abundance populations (MAPs) are also coeval, or mono-age, populations. Here we study this relationship for a M...

Recent improvements in the age dating of stellar populations and single stars allow us to study the ages and abundance of stars and galaxies with unprecedented accuracy. We here compare the relation between age and \alpha-element abundances for stars in the solar neighborhood to that of local, early-type galaxies. We find both relations to be very...

Lenticular galaxies (S0s) represent the majority of early-type galaxies in the local Universe, but their formation channels are still poorly understood. While galaxy mergers are obvious pathways to suppress star formation and increase bulge sizes, the marked parallelism between spiral and lenticular galaxies (e.g. photometric bulge-disc coupling) s...

The stellar radial profiles of disk galaxies are often observed to be truncated, or anti-truncated in the galaxies’ outskirts. As of now, the literature about galaxy formation lacks a model for the formation of observed anti-truncated stellar disks which is based on secular processes. We present an attempt to fill this gap. We were able to model an...

We show that the masses of red giant stars can be well predicted from their photospheric carbon and nitrogen abundances, in conjunction with their spectroscopic stellar labels log g, Teff, and [Fe/H]. This is qualitatively expected from mass-dependent post-main-sequence evolution. We here establish an empirical relation between these quantities by...

We show that the masses of red giant stars can be well predicted from their photospheric carbon and nitrogen abundances, in conjunction with their spectroscopic stellar labels log g, Teff, and [Fe/H]. This is qualitatively expected from mass-dependent post main sequence evolution. We here establish an empirical relation between these quantities by...

Simple numerical models can produce the observed radial breaks in the stellar surface density profile of late-type galaxies by varying only one parameter, the initial halo spin {\lambda}. Here we analyse these simulations in more detail in an effort to identify the physical mechanism that leads to the formation of anti-truncations (Type-III profile...

We study the properties of bars in a series of zoom cosmological simulations (Martig et al.2012, Kraljic et al.2012). We find that bars are almost absent from galaxies at z>1, and if they form they tend to be quickly destroyed by mergers and instabilities. On the contrary, at z<1 bars are long-lived, and the fraction of barred galaxies rises steadi...

Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars with high [alpha/Fe] ratios and thus old) has a smaller scale-length than the thin disk. This is in apparent contradiction with observations of external edge-on galaxies, where the thickened components extend at least as much as the thin ones. M...

In comparison to gas and dust in star-forming galaxies at the peak epoch of galaxy assembly, which are presently the topic of intense study, little is known about the interstellar medium (ISM) of distant, passively evolving galaxies. We report on a deep 3 mm-band search with IRAM/PdBI for molecular gas in a massive ($M_{\star}{\sim}6{\times}10^{11}...

The radial density profiles of stellar galaxy discs can be well approximated as an exponential. Compared to this canonical form, however, the profiles in the majority of disc galaxies show downward or upward breaks at large radii. Currently, there is no coherent explanation in a galaxy formation context of the radial profile per se, along with the...

We derive age constraints for 1639 red giants in the APOKASC sample for which seismic parameters from Kepler, as well as effective temperatures, metallicities and [α/Fe] values from APOGEE DR12 (Apache Point Observatory Galactic Evolution Experiment Data Release 12) are available. We investigate the relation between age and chemical abundances for...

We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due to...

We study the relationship between the structure and star-formation rate (SFR) of X-ray selected low and moderate luminosity active galactic nuclei (AGNs) in the two Chandra Deep Fields, using Hubble Space Telescope imaging from the Cosmic Assembly Near Infrared Extragalactic Legacy Survey (CANDELS) and deep far-infrared maps from the PEP+GOODS-Hers...

Galactic Archaeology, i.e. the use of chemo-dynamical information for stellar samples covering large portions of the Milky Way to infer the dominant processes involved in its formation and evolution, is now a powerful method thanks to the large recently completed and ongoing spectroscopic surveys. It is now important to ask the right questions when...

We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R_25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due t...

We determine the intrinsic, 3-dimensional shape distribution of star-forming galaxies at 0<z<2.5, as inferred from their observed projected axis ratios. In the present-day universe star-forming galaxies of all masses 1e9 - 1e11 Msol are predominantly thin, nearly oblate disks, in line with previous studies. We now extend this to higher redshifts, a...

We study seven simulated disk galaxies, three with a quiescent merger history, and four with mergers in their last 9 Gyr of evolution. We compare their structure at z=0 by decomposing them into "mono-age populations" (MAPs) of stars within 500 Myr age bins. All studied galaxies undergo a phase of merging activity at high redshift, so that stars old...

We study the relation between stellar ages and vertical velocity dispersion (the age–velocity relation, or AVR) in a sample of seven simulated disc galaxies. In our simulations, the shape of the AVR for stars younger than 9 Gyr depends strongly on the merger history at low redshift, with even 1:10–1:15 mergers being able to create jumps in the AVR...

We study the relation between stellar ages and vertical velocity dispersion (the age-velocity relation, or AVR) in a sample of seven simulated disk galaxies. In our simulations, the shape of the AVR for stars younger than 9 Gyr depends strongly on the merger history at low redshift, with even 1:10 - 1:15 mergers being able to create jumps in the AV...

We study seven simulated disk galaxies, three with a quiescent merger history, and four with mergers in their last 9 Gyr of evolution. We compare their structure at z=0 by decomposing them into "mono-age populations" (MAPs) of stars within 500 Myr age bins. All studied galaxies undergo a phase of merging activity at high redshift, so that stars old...

Many techniques have been used in the literature for determining which particles or cells in a hydrodynamic simulation are attached to a galaxy. Often these invoke a spherical aperture that defines the boundary between the galaxy and the rest of its parent (sub)halo, sometimes coupled with, or alternatively involving, the use of a subhalo finder an...

Direct N-body simulations of globular clusters in a realistic Milky Way-like potential are carried out using the code NBODY6 to determine the impact of the host galaxy disk mass and geometry on the survival of star clusters. A relationship between disk mass and star cluster dissolution timescale is derived. These N-body models show that doubling th...

In the first paper of this series (paper I) we presented a new approach for studying the chemodynamical evolution in disk galaxies, focusing on the Milky Way. While in paper I we studied extensively the Solar vicinity, here we extend these results to different distances from the Galactic center. We show that contamination by radial migration become...

Despite the recent advancements in the field of galaxy formation and evolution, fully self-consistent simulations are still unable to make the detailed predictions necessary for the planned and ongoing large spectroscopic and photometry surveys of the Milky Way disc. These difficulties arise from the very uncertain nature of sub-grid physical energ...

We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H<24.5 involving the dedicated efforts of 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50,000 galaxies up to z<4 over all the fields. Here, we present our detailed visual classi...