# Astrofísica Numérica: Formación y Evolución de Galaxias

Año de inicio
2015

General
Descripción

Entre las cuestiones fundamentales en Astronomía y Astrofísica están la formación y evolución de galaxias. Las escalas de tiempo y tamaño son tan astronómicas que su observación en galaxias individuales es imposible. Solo con el uso de simulaciones numéricas es posible entender la formación de estructuras cósmicas dentro del actual marco cosmológico.

Los principales procesos físicos que rigen la formación y evolución de galaxias son gravedad, hidrodinámica, gas cooling, formación estelar, evolución estelar, y SN y BH feedback, todos ellos no lineales y por ello difíciles de describir con modelos puramente analíticos. Otros modelos, los semi-analíticos, se basan en simulaciones de únicamente materia oscura y están, por tanto, sesgados al igual que éstas. Por todo esto, las simulaciones cosmológicas hidrodinámicas son la mejor herramienta para realizar los “experimentos controlados” de formación y evolución de galaxias.

Tras tres décadas de mejoras en las simulaciones numéricas, solo ahora los trabajos teóricos pueden reproducir simultáneamente las propiedades observadas de las galaxias y del medio interestelar (e.g. EAGLE, Schaye et al. 2015, MNRAS, 446, 521; ILLUSTRIS, Vogelsberger et al., 2014, Nature, 509, 177); en particular, las funciones de luminosidad y de masa de las galaxias, las relaciones entre tamaño y masa, entre metalicidad y masa, entre otras muchas propiedades están reproducidas en un amplio rango de masas de galaxias.

El grupo de astrofísica numérica trabaja en una variedad de temas científicos relacionados con la evolución de las galaxias y la estructura a gran escala del universo. La experiencia abarca desde la estructura interna de las galaxias enanas y de bajo brillo superficial, la Vía Láctea y sus galaxias satélite, el estudio de las galaxias en grupos y agrupaciones, hasta las grandes simulaciones cosmológicas de la estructura del universo. El grupo colabora con la mayoría de los grupos de investigación de IAC que trabajan en astrofísica extragaláctica y cosmología.

Prof.
Prof.
Joop Schaye
Dr.
Yannick Bahé
Prof.
Gustavo Yepes
Prof.
Daisuke Kawata
Prof.
Andrea Macciò
Prof.
Alexander Knebe
Dr.
Hidenobu Yashima
Dr.
Robert Grand

• Formation of the first galaxies in the aftermath of the first supernovae

We perform high-resolution cosmological hydrodynamic simulations to study the formation of the first galaxies that reach the masses of 108 - 9 h-1 M⊙ at z = 9. The resolution of the simulations is high enough to resolve minihaloes and allow us to successfully pursue the formation of multiple Population (Pop) III stars, their supernova (SN)

Abe, Makito et al.

### Fecha de publicación:

12
2021
• A Shallow Dark Matter Halo in Ultra-diffuse Galaxy AGC 242019: Are UDGs Structurally Similar to Low-surface-brightness Galaxies?

A central question regarding ultra-diffuse galaxies (UDGs) is whether they are in a separate category from low-surface-brightness (LSB) galaxies, or just their natural continuation toward low stellar masses. In this Letter, we show that the rotation curve of the gas rich UDG AGC 242019 is well fit by a dark matter halo with an inner slope that

Brook, Chris B. et al.

### Fecha de publicación:

9
2021
• Pericentric passage-driven star formation in satellite galaxies and their hosts: CLUES from local group simulations

Local Group satellite galaxies show a wide diversity of star formation histories (SFHs) whose origin is yet to be fully understood. Using hydrodynamical simulations from the Constrained Local UniversE project, we study the SFHs of satellites of Milky Way-like galaxies in a cosmological context: while in the majority of the cases the accretion on to

Di Cintio, Arianna et al.

### Fecha de publicación:

9
2021
• Origin of stellar prolate rotation in a cosmologically simulated faint dwarf galaxy

Stellar prolate rotation in dwarf galaxies is rather uncommon, with only two known galaxies in the Local Group showing such feature (Phoenix and And II). Cosmological simulations show that in massive early-type galaxies prolate rotation likely arises from major mergers. However, the origin of such kinematics in the dwarf galaxies regime has only

### Fecha de publicación:

7
2021
• 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 arising

Scholz-Díaz, Laura et al.

### Fecha de publicación:

8
2021
• Higher order Hamiltonian Monte Carlo sampling for cosmological large-scale structure analysis

We investigate higher order symplectic integration strategies within Bayesian cosmic density field reconstruction methods. In particular, we study the fourth-order discretization of Hamiltonian equations of motion (EoM). This is achieved by recursively applying the basic second-order leap-frog scheme (considering the single evaluation of the EoM)

Hernández-Sánchez, Mónica et al.

### Fecha de publicación:

4
2021
• Evaluating hydrodynamical simulations with green valley galaxies

We test cosmological hydrodynamical simulations of galaxy formation regarding the properties of the blue cloud (BC), green valley (GV), and red sequence (RS), as measured on the 4000Å break strength versus stellar mass plane at z = 0.1. We analyse the RefL0100N1504 run of EAGLE and the TNG100 run of IllustrisTNG project, by comparing them with the

Angthopo, J. et al.

### Fecha de publicación:

4
2021
• Self-interacting dark matter and the delay of supermassive black hole growth

Using cosmological hydrodynamic simulations with physically motivated models of supermassive black hole (SMBH) formation and growth, we compare the assembly of Milky Way-mass (Mvir ≍ 7 × 1011 M☉ at z = 0) galaxies in cold dark matter (CDM) and self-interacting dark matter (SIDM) models. Our SIDM model adopts a constant cross-section of 1 cm2 g-1

Cruz, A. et al.

### Fecha de publicación:

1
2021
• Stellar splashback: the edge of the intracluster light

We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the 'edges' of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter, commonly used as a proxy for the splashback radius, is located at $\sim \, r_{200 \rm m}$ ; the strength and location of this feature depends on the recent

Deason, Alis J. et al.

### Fecha de publicación:

1
2021
• The discovery of the most UV-Ly α luminous star-forming galaxy: a young, dust- and metal-poor starburst with QSO-like luminosities

We report the discovery of BOSS-EUVLG1 at z = 2.469, by far the most luminous, almost un-obscured star-forming galaxy known at any redshift. First classified as a QSO within the Baryon Oscillation Spectroscopic Survey, follow-up observations with the Gran Telescopio Canarias reveal that its large luminosity, MUV ≃ -24.40 and log(LLyα/erg s-1) ≃ 44

Marques-Chaves, R. et al.

### Fecha de publicación:

9
2020
• The First Billion Years project: Finding infant globular clusters at z = 6

Aims: We aim to conduct an assessment of the demographics of substructures in cosmological simulations to identify low-mass stellar systems at high redshift, with a particular focus on globular cluster (GC) candidates. Methods: We explored a suite of high-resolution cosmological simulations from the First Billion Years Project (FiBY) at z ≥ 6. All

Phipps, Frederika et al.

### Fecha de publicación:

9
2020
• NIHAO XXIV: rotation- or pressure-supported systems? Simulated Ultra Diffuse Galaxies show a broad distribution in their stellar kinematics

In recent years, a new window on galaxy evolution opened, thanks to the increasing discovery of galaxies with a low-surface brightness, such as Ultra Diffuse Galaxies (UDGs). The formation mechanism of these systems is still a much debated question and so are their kinematical properties. In this work, we address this topic by analysing the stellar

### Fecha de publicación:

7
2020
• Constraining the inner density slope of massive galaxy clusters

We determine the inner density profiles of massive galaxy clusters (M200 > 5 × 1014 M☉) in the Cluster-EAGLE (C-EAGLE) hydrodynamic simulations, and investigate whether the dark matter density profiles can be correctly estimated from a combination of mock stellar kinematical and gravitational lensing data. From fitting mock stellar kinematics and

He, Qiuhan et al.

### Fecha de publicación:

6
2020
• Explaining the chemical trajectories of accreted and in-situ halo stars of the Milky Way

The Milky Way underwent its last significant merger ten billion years ago, when the Gaia-Enceladus-Sausage (GES) was accreted. Accreted GES stars and progenitor stars born prior to the merger make up the bulk of the inner halo. Even though these two main populations of halo stars have similar durations of star formation prior to their merger, they

Brook, Chris B. et al.

### Fecha de publicación:

4
2020
• Kinematic analysis of eagle simulations: evolution of λ<SUB>Re</SUB> and its connection with mergers and gas accretion

We have developed a new tool to analyse galaxies in the eagle simulations as close as possible to observations. We investigated the evolution of their kinematic properties by means of the angular momentum proxy parameter, λRe, for galaxies with M⋆ ≥ 5 × 109 M☉ in the RefL0100N1504 simulation up to redshift two (z = 2). Galaxies in the simulation

Walo-Martín, D. et al.

### Fecha de publicación:

5
2020
• The mass of our Galaxy from satellite proper motions in the Gaia era

We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass of the Milky Way using the scale-free mass estimator of Watkins et al. (2010). We first determine the anisotropy parameter β, and the tracer satellites' radial density index γ to be β = $-0.67^{+0.45}_{-0.62}$ and γ = 2.11 ± 0.23. When we exclude possible former

Fritz, T. K. et al.

### Fecha de publicación:

4
2020
• Sub one per cent mass fractions of young stars in red massive galaxies

Early-type galaxies are considered to be the end products of massive galaxy formation1. Optical spectroscopic studies reveal that massive early-type galaxies formed the bulk of their stars over short timescales (≲?1 Gyr) and at high redshift (z ≳? 2), followed by passive evolution to the present2. However, their optical spectra are unable to

### Fecha de publicación:

2
2020
• The intracluster light as a tracer of the total matter density distribution: a view from simulations

By using deep observations of clusters of galaxies, it has been recently found that the projected stellar mass density closely follows the projected total (dark and baryonic) mass density within the innermost ∼140 kpc. In this work, we aim to test these observations using the Cluster-EAGLE simulations, comparing the projected densities inferred

Alonso Asensio, Isaac et al.

### Fecha de publicación:

4
2020
• Deep spectroscopy in nearby galaxy clusters - V. The Perseus cluster

Dwarfs are the largest population of galaxies in number in the nearby Universe. Deep spectroscopic data are still missing to obtain a better understanding of their formation and evolution processes. This study shows the results obtained from a spectroscopic campaign in the Perseus cluster. We have obtained 963 new galaxy spectra. We have measured

Aguerri, J. A. L. et al.

### Fecha de publicación:

3
2020
• Signatures of the Galactic bar in high-order moments of proper motions measured by Gaia

Our location in the Milky Way provides an exceptional opportunity to gain insight on the galactic evolution processes, and complement the information inferred from observations of external galaxies. Since the Milky Way is a barred galaxy, the study of motions of individual stars in the bulge and disc is useful to understand the role of the bar. The

Palicio, Pedro A. et al.

2
2020