Welcome to the Traces of Galaxy Formation research group website.
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
A complex star formation history, as the one expected to describe galaxy evolution, needs a multidisciplinary approach to be fully understood. Our group at the IAC consists of experienced researchers in cosmological simulations, dynamical studies, stellar populations and morphological properties of galaxies up to high redshift. We combine different approaches (e.g. observations and theory, secular and cosmological evolution studies) to obtain a complete view of the dominant mechanisms driving the evolution of galaxies.
Within this general framework, we are currently exploring three main areas of research:
- Stellar population synthesis models
- Development of new stellar population synthesis models
- Stellar population analysis tools
- Universality of the stellar initial mass function (IMF)
- Cosmic evolution of galaxies
- Massive galaxy evolution
- Stellar populations in different environments
- Low surface brightness science
- Machine learning and cosmological simulations
- Evolutionary processes in nearby galaxies
- The role of black holes in the evolution of galaxies
- Surveys of nearby galaxies
- Stellar kinematics and dynamical models
If you want to get in contact or work with us, please send an email to the head of the group (Ignacio Martín-Navarro ignacio.martin [at] iac.es).
Here you can find some of our most recent highlights:
- Local variations of the stellar velocity ellipsoid - II. The effect of the bar in the inner regions of Auriga galaxies. Walo et al. 2022, MNRAS (https://ui.adsabs.harvard.edu/abs/2022MNRAS.513.4587W)
- Anisotropic satellite galaxy quenching modulated by black hole activity. Martín-Navarro et al. 2021, Nature (https://ui.adsabs.harvard.edu/abs/2021Natur.594..187M)
- Evaluating hydrodynamical simulations with green valley galaxies. Angthopo et al. 2021, MNRAS (https://ui.adsabs.harvard.edu/abs/2021MNRAS.502.3685A)
- Sub one per cent mass fractions of young stars in red massive galaxies. Salvador-Rusiñol et al. 2020, Nature Astronomy (https://ui.adsabs.harvard.edu/abs/2020NatAs...4..252S)
- Detection of young stellar populations in apparently quenched low-mass galaxies using red spectral line indices. de Lorenzo-Cáceres et al. 2020, MNRAS (https://ui.adsabs.harvard.edu/abs/2020MNRAS.498.1002D)
Introducing the LBT Imaging of Galactic Halos and Tidal Structures (LIGHTS) survey. A preview of the low surface brightness Universe to be unveiled by LSST
We present the first results of the LBT Imaging of Galaxy Haloes and Tidal Structures (LIGHTS) survey. LIGHTS is an ongoing observational campaign with the 2 × 8.4 m Large Binocular Telescope (LBT) aiming to explore the stellar haloes and the low surface brightness population of satellites down to a depth of μV ∼ 31 mag arcsec−2 (3σ in 10″ × 10″Trujillo, Ignacio et al.
A Disk and No Signatures of Tidal Distortion in the Galaxy "Lacking" Dark Matter NGC 1052-DF2
Using ultra-deep imaging (μg = 30.4 mag arcsec-2; 3σ, 10″ × 10″), we probed the surroundings of the first galaxy "lacking" dark matter (DM) KKS2000 (NGC 1052-DF2). Signs of tidal stripping in this galaxy would explain its claimed low content of DM. However, we find no evidence of tidal tails. In fact, the galaxy remains undisturbed down to aMontes, Mireia et al.
Surface brightness fluctuations to constrain secondary stellar populations: revealing very low-metallicity stars in massive galaxies
The aim of this work is to explore the potential of surface brightness fluctuations (SBF) for studying composite stellar populations (CSP). To do so, we have computed the standard (mean) and SBF spectra with E-MILES stellar population synthesis code. We have created a set of models composed by different mass fractions of two single stellarRodríguez-Beltrán, P. et al.
The miniJPAS survey: A preview of the Universe in 56 colors
The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2 deg2 field-of-view withBonoli, S. et al.
The Fornax 3D project: PNe populations and stellar metallicity in edge-on galaxies
Context. Extragalactic planetary nebulae (PNe) are useful distance indicators and are often used to trace the dark-matter content in external galaxies. At the same time, PNe can also be used as probes of their host galaxy stellar populations and to help understand the later stages of stellar evolution. Previous works have indicated that a specificGalán-de Anta, P. M. et al.
The lens SW05 J143454.4+522850: a fossil group at redshift 0.6?
Fossil groups are considered the end product of natural galaxy group evolution in which group members sink towards the centre of the gravitational potential due to dynamical friction, merging into a single, massive, and X-ray bright elliptical. Since gravitational lensing depends on the mass of a foreground object, its mass concentration, andDenzel, Philipp et al.
Local variations of the Stellar Velocity Ellipsoid-I: the disc of galaxies in the Auriga simulations
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 theseWalo-Martín, Daniel et al.
Pushing automated morphological classifications to their limits with the Dark Energy Survey
We present morphological classifications of ~27 million galaxies from the Dark Energy Survey (DES) Data Release 1 (DR1) using a supervised deep learning algorithm. The classification scheme separates: (a) early-type galaxies (ETGs) from late-type galaxies (LTGs); and (b) face-on galaxies from edge-on. Our convolutional neural networks (CNNs) areVega-Ferrero, J. et al.
The ultraviolet luminosity function of star-forming galaxies between redshifts of 0.6 and 1.2
We use ultraviolet (UV) imaging taken with the XMM-Newton Optical Monitor telescope (XMM-OM), covering 280 arcmin2 in the UVW1 band (λeff = 2910 Å) to measure rest-frame UV 1500-Å luminosity functions of galaxies with redshifts z between 0.6 and 1.2. The XMM-OM data are supplemented by a large body of optical and infrared imaging to providePage, M. J. et al.
Extending the evolution of the stellar mass-size relation at z ≤ 2 to low stellar mass galaxies from HFF and CANDELS
We reliably extend the stellar mass-size relation over 0.2 ≤ z ≤ 2 to low stellar mass galaxies by combining the depth of Hubble Frontier Fields with the large volume covered by CANDELS. Galaxies are simultaneously modelled in multiple bands using the tools developed by the MegaMorph project, allowing robust size (i.e. half-light radius) estimatesNedkova, Kalina V. et al.
The size function of massive satellites from the R<SUB>e</SUB>-R<SUB>h</SUB> and M<SUB>star</SUB>-M<SUB>h</SUB> relations: constraining the role of environment
In previous work, we showed that a semi-empirical model in which galaxies in host dark matter haloes are assigned stellar masses via a stellar mass-halo mass (SMHM) relation and sizes (Re) via a linear and tight Re-Rh relation can faithfully reproduce the size function of local Sloan Digital Sky Survey (SDSS) central galaxies and the strong sizeZanisi, L. et al.
Constraints on the dust extinction law of the Galaxy with Swift/UVOT, Gaia, and 2MASS
We explore variations of the dust extinction law of the Milky Way by selecting stars from the Swift/UVOT Serendipitous Source Catalogue, cross-matched with Gaia DR2 and 2MASS to produce a sample of 10 452 stars out to ~4 kpc with photometry covering a wide spectral window. The near ultraviolet passbands optimally encompass the 2175 Å bump, so thatFerreras, Ignacio et al.
The SAMI Galaxy Survey: the third and final data release
We have entered a new era where integral-field spectroscopic surveys of galaxies are sufficiently large to adequately sample large-scale structure over a cosmologically significant volume. This was the primary design goal of the SAMI Galaxy Survey. Here, in Data Release 3, we release data for the full sample of 3068 unique galaxies observed. ThisCroom, Scott M. et al.
Mild radial variations of the stellar IMF in the bulge of M31
Using new, homogeneous, long-slit spectroscopy in the wavelength range from ~0.35 to $\sim 1 \, \mu$m, we study radial gradients of optical and near-infrared (NIR) initial mass function (IMF)-sensitive features along the major axis of the bulge of M31, out to a galactocentric distance of ~200 arcsec (~800 pc). Based on state-of-the-art stellarLa Barbera, F. et al.
Anisotropic satellite galaxy quenching modulated by black hole activity
The evolution of satellite galaxies is shaped by their constant interaction with the circumgalactic medium surrounding central galaxies, which in turn may be affected by gas and energy ejected from the central supermassive black hole1-6. The nature of such a coupling between black holes and galaxies is, however, much debated7-9 and observationalMartín-Navarro, Ignacio et al.
The evolution of compact massive quiescent and star-forming galaxies derived from the R<SUB>e</SUB>-R<SUB>h</SUB> and M<SUB>star</SUB>-M<SUB>h</SUB> relations
The mean size (effective radius Re) of massive galaxies (MGs; Mstar > 1011.2M⊙) is observed to increase steadily with cosmic time. It is still unclear whether this trend originates from the size growth of individual galaxies (via, e.g. mergers and/or AGN feedback) or from the inclusion of larger galaxies entering the selection at later epochsZanisi, L. et al.
Diversity of nuclear star cluster formation mechanisms revealed by their star formation histories
Nuclear star clusters (NSCs) are the densest stellar systems in the Universe and are found in the centres of all types of galaxies. They are thought to form via mergers of star clusters such as ancient globular clusters (GCs) that spiral to the centre as a result of dynamical friction or through in situ star formation directly at the galaxy centreFahrion, K. et al.
History of the gas fuelling star formation in EAGLE galaxies
Theory predicts that cosmological gas accretion plays a fundamental role fuelling star formation in galaxies. However, a detailed description of the accretion process to be used when interpreting observations is still lacking. Using the state-of-the-art cosmological hydrodynamical simulation EAGLE, we work out the chemical inhomogeneities arisingScholz-Díaz, Laura et al.
An extension of the MILES library with derived T<SUB>eff</SUB>, log g, [Fe/H], and [α/Fe]
Extragalactic astronomy and stellar astrophysics are intrinsically related. In fact, the determination of important galaxy properties such as stellar masses, star formation histories, or chemical abundances relies on the ability to model their stellar populations. One important ingredient of these models is stellar libraries. Empirical librariesGarcía Pérez, A. E. et al.
A Duality in the Origin of Bulges and Spheroidal Galaxies
Studying the resolved stellar populations of the different structural components that build massive galaxies directly unveils their assembly history. We aim at characterizing the stellar population properties of a representative sample of bulges and pure spheroids in massive galaxies (M⋆ > 1010 M⊙) in the GOODS-N field. We take advantage of theCostantin, Luca et al.