Interplay between evolved massive stars and their circumstellar medium : a (SUB) millimetre view of luminous blue variable mass loss

Massive stars play a significant role in the shaping and evolution of the Galaxy. Their stellar winds and strong UV fields continuously alter the structure, dynamics and chemical composition of the surrounding ISM. Still, their impact becomes even more relevant once they leave the main sequence. They turn unstable and progressively lose a significant fraction […]

Study of the early stages in the formation of super star clusters

This thesis aims to study the earliest heavily obscured phases of massive star formation in starburst (SB) galaxies through a multi-line analysis of the HC 3 N rotational transitions from the ground and vibrationally excited states (HC 3 N). Due to its unique spectroscopic properties, we also discuss the potential of HC 3 N as […]

MONOS: Multiplicity of Northern O-type Spectroscopic Systems

One of the key pillars in our understanding of the chemical (Matteucci 2012) and dynamical evolution of galaxies is our knowledge about massive stars (Massey 2003), and the O-type stars (M ZAMS ⇠ 15/20 60/80 M ) in particular. Massive stars play a crucial role in shaping their environment due to their thrilling short lives […]

The first massive galaxies formed in the Universe: selection and characterization of optically faint, infrared-bright galaxies in the first 2 Gyr of the Universe

The ultimate goal in galaxy studies is having a complete picture of galaxy formation and evolution across the history of the Universe. A robust determination of the abundance of massive (an even quiescent) galaxies at high redshift is essential to constrain current models of galaxy formation and alleviate the tension between existing models and observations. […]

Exocomets: a study of the gaseous environment of A-type main-sequence stars

En las estrellas de secuencia principal, los excesos fotométricos en el infrarrojo atribuidos a la presencia de polvo circunestelar en los discos conocidos como debris o escombro, ha sido la única prueba empírica indirecta de la existencia de cuerpos menores durante más de 40 años. No fue hasta 1987 cuando se encontró la primera evidencia de la […]

GALANTE: Photometric System and Galactic Plane Survey

GALANTE project has the goal to observe the Northern Hemisphere, 6 degrees wide, in the optical range. To reach this goal, 7 photometric bands have been selected to obtain the most complete information about the stellar physical variables. The new photometric system GALANTE has been designed using 4 J-PLUS bands in addition with 3 home-made […]

Physical and Chemical Processes in Cloud-Cloud Collisions: Star Formation on the Making

Infrared Dark Clouds (IRDCs) are cold and dense regions in space, considered as the birthplace of high-mass stars and stellar clusters. Recent studies support the idea that the physical mechanisms leading to the formation of these IRDCs may also trigger high-mass star formation within the clouds. Fossil records of such formation mechanisms may be stored […]

Un sondeo espectroscópico de estrellas o galácticas

Los catálogos de clasificaciones espectrales de estrellas masivas que recopilan sus datos de diferentes fuentes, muestran una gran disparidad en las clasificaciones que contienen. Algunas de las discrepancias se deben a las diferentes resoluciones espectrales o relaciones señal-ruido (S/N), otras a la variabilidad en las estrellas (siendo las binarias espectroscópicas las principales culpables), y otros […]

The impact of metallicity on massive star evolution

The accurate characterization of the physical properties of massive stars in very low-metallicity environments has important implications in our interpretation of the primitive Universe. The first population of stars, which are thought to have been very massive and extremely metal-poor, has been proposed as the responsible source of the re-ionization of the early Universe. Moreover, […]

Infrared emission of active galaxies

La emisión infrarroja de galaxias activas Nowadays it is accepted that all galaxies with significant bulge component contain a supermassive black hole (SMBH) in their centres. This SMBH plays an important role in the formation of galaxies, being quiet in some galaxies and accreting material and growing in others. The latter phenomenon is referred to […]

CARMENES-UCM: scientific preparation, multiplicity, chromospheric activity and kinematics

CARMENES-UCM: preparación científica, multiplicidad, actividad cromosférica y cinemática Las estrellas enanas de tipo M representan cerca de dos tercios de las estrellas en la Galaxia, lo que las convierte en objetivos perfectos para el estudio de formación y evolución estelar al final del diagrama Hertzsprung-Russell. El máximo de emisión de energía de las estrellas M […]

Cúmulos jóvenes masivos en el infrarrojo como sondas Galácticas

Los cúmulos jóvenes masivos (YMCs) espacialmente resueltos disfrutan de un singular conjunto de propiedades físicas, evolutivas y observacionales que los convierten en laborato- rios astrofísicos privilegiados. Están formados por una abundante población estelar coetánea, codistante, y de la misma composición química inicial, que muestrea toda o casi toda la función inicial de masas (IMF). Cada […]

Lessons from high-energy studies of AGN: X-ray absorption and its variability

Lecciones del estudio de AGN a altas energías: absorción de rayos X y su variabilidad This is a doctoral dissertation about the X–ray observational and theoretical study of active galactic nuclei (AGN). In the following paragraphs, the research lines addressed during my Ph. D. work are exposed. From a theoretical approach, my work belongs to […]

A Search For Neutral Gas Outflows In Nearby Luminous Star-Forming Galaxies

In the last decade, our understanding of the formation and evolution of galaxies over cosmic time has been significantly enhanced by large scale galaxy surveys. These surveys have drawn a detailed pic- ture of the global properties of the galaxies, establishing the galaxy stellar mass function and scaling relations (e.g., mass-metallicity). Galaxy evolution models attempt […]

Búsqueda IR de starburst y del toroide de polvo oscurecedor en QSO

Con el propósito de estudiar la contribución estelar y de un toroide de polvo nuclear a la emisión nuclear (. 1 kpc) en el cercano y mediano IR (2-20 μm) de cuásares (QSO, del inglés Quasi Stellar Object) hemos realizado observaciones en el Gran Telescopio CANARIAS de 10.4 m (GTC) de 20 QSO cercanos (z […]

CARMENES science preparation: characterisation of M dwarfs with low-resolution spectroscopy and search for low-mass wide companions to young stars

Preparación científica de CARMENES : caracterización de enanas M con espectroscopía de baja resolución y búsqueda de compañeros separados poco masivos de estrellas jóvenes The mass ratio between rocky planets and M-type dwarfs is much lower than between rocky planets and stars like the Sun. This fact has made them prime targets for the detection […]

Submillimetric study of nearby galaxies

Estudio submilimétrico de galaxias cercanas The formation of molecules in the Interstellar medium is possible under the condition of high densities in a given region as the consequence of the occurrence of collisions between atoms. Moreover, a molecule can be dissociated by an UV photon. Interestelar dust can act as a pro- tection against dissociation […]

Protoplanetary disk evolution in nearby star-forming regions

The main aim of this work is to better understand the evolution of protoplanetary disks around young stars in the solar neighborhood. It comprises three rst authored published papers, a fourth paper about to be submitted, and additional research as participation in six other refereed papers, which I coauthored during the period of this thesis. […]

Optical and high-energy monitoring of variable sources observed with INTEGRAL/OMC

Since the discovery of the first variable stars in the 16th century, their study has been one of the principal areas of astronomical research. During the 20th century and the beginning of the 21st, many optical photometric surveys have been carried out with the aim of understanding the physical mechanisms producing the observed variations of […]

Multi-wavelength study of the population of galaxies in intermediate-redshift clustersthe case of rxj1257.2+4738 at z~0.9

“Clusters of galaxies are the largest virialised systems in the Universe” is one of the most common statements in the framework of galaxy clusters research. This occurs because such gravitationally bound structures become ideal laboratories to directly study their baryon content (intracluster medium and galaxies) and to indirectly measure their dark matter content. In the […]

Química en las nubes moleculares del Centro Galáctico

La investigación que se desarrolla en esta tesis doctoral se centra en el estudio de dos de los principales complejos del Centro Galáctico (CG), Sagitario (Sgr) B2 y Sgr A, a través de la medición de la emisión/absorción procedente de estas fuentes en el rango de longitudes de onda centimétricas-submilimétricas. El CG se encuentra a […]

The role of low-mass star clusters in the formation of massive stars

Massive stars (M>8M⊙) are the main source of energy and turbulence injection into the interstellar medium (ISM) of galaxies. Despite their importance, their formation process is still not well understood, being one of the most debated topic in modern Astrophysics. Several theories have been proposed to explain the formation of the most massive stars: i) […]

Complejidad física y química en la nube molecular orión KL

El medio interestelar constituye un importante campo de investigación, especialmente para la Astrofísica Molecular. Las grandes cantidades de gas molecular presentes en el medio interestelar, ISM, que se agrupan formando complejos de nubes moleculares, son un laboratorio único para conocer en detalle su composición a través de la Astroquímica. Esta rama de la ciencia representa […]

2D kinematic characterization of a representative sample of local (U)LIRGs: A “kinemetry” analysis based on VIMOS/VTL Integral Field Spectroscopy

Luminous and ultraluminous infrared galaxies (i.e., LIRGs, LIR = [8-1000 μm] = 1011 – 1012 L⊙, and ULIRGs, LIR > 1012 L⊙, respectively) host the most extreme star-forming events in the present universe. Although they are rare in the local universe, they are much more numerous at high-z and are relevant contributors to the whole past star formation beyond z ∼ 1. Local (U)LIRGs […]

A VLT-SINFONI study of local Luminous and Ultraluminous infrared galaxies

Estudio de galaxias luminosas y ultraluminosas en el infrarrojo con VTL-SINFONI The importance of Luminous (LIRGs) and Ultraluminous (ULIRGs) infrared galaxies in the context of galaxy evolution has been clearly established since their discovery in the early 70’s. This new class of “infrared galaxies” is characterised by emitting more energy in the mid- and far-infrared […]

A search for low-mass objects in young star-forming regions

The object of this thesis is find new low-mass objects in Taurus in order to get new insights on its mass function. The investigated area in this work is located 5 deg north of the main clouds and covers around 25 sq:deg. Thus, we also contribute to answer the question whether the low-mass objects have […]

Star formation and high-energy emission in starburst galaxies

Starbursts are conspicuous star formation events which are characterized by a prompt production of massive stars. They dominate the emission of the host galaxies in most of the electromagnetic spectrum over several million years and observationally appear similar to HII regions (Sargent & Searle 1970). The strong UV emission from these stars is more powerful […]

Estudio experimental del procesamiento fotónico y térmico de hielos interestelares

El medio interestelar (ISM) es el espacio que hay entre las estrellas, dentro del ISM se puede distinguir el medio difuso, compuesto principalmente por hidrógeno atómico. Si la densidad sigue aumentando se empezarían a formar las nubes moleculares que se componen principalmente por hidrógeno molecular y polvo. Dentro de una nube molecular la densidad de […]

Star Formation and Nuclear Activity of Local Luminous Infrared Galaxies

Luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies (ULIRGs) are galaxies with infrared (IR) luminosities (LIR) in the range between 1011 and 1012 L⊙, and >1012 L⊙, respectively. Intense star-formation bursts and/or an active galactic nucleus (AGN) are the power sources of these galaxies. These galaxies are unusual in the local universe, they represent less than 6 % of […]

Accretion and circumstellar properties of Herbig Ae/Be stars

This work focuses on the massive counterparts of classical T-Tauri stars, the so-called Herbig Ae/Be (HAeBe) stars. These are the most massive objects to experience an optically visible pre-main sequence (PMS) phase, bridging the transition between low and high-mass young stars. Our knowledge about the HAeBe properties is much more limited than that for lower-mass […]

Fotometría óptica desde el espacio: la cámara OMC a bordo de INTEGRAL

El trabajo que presentamos en esta tesis tiene como finalidad la operación, calibración y análisis de datos ópticos del instrumento OMC (Optical Monitoring Camera) a bordo del satélite INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory). La cámara OMC ofrece, por primera vez, la oportunidad de realizar observaciones fotométricas de larga duración en el rango óptico, simultáneamente con […]

The Lambda Orionis star forming region. Spectroscopic Characterization

The Lambda Orionis Star Forming Region is part of the Orion molecular cloud complex, it is located about 15 degree north of the center of the complex (δ ∼ 10 degrees). λ Ori, itself is the brightest member of Collinder 69, a well-defined, compact open cluster at the center of the star forming region. Two other already identified and […]

The Lambda Orionis star forming region: A multi wavelength approach

The Head of Orion or Lambda Orionis Star Forming Region is part of the Orion molecular cloud complex, but at δ ∼ +10 ◦, it is located about 15◦ north of the center of the complex. The star λ Ori is the brightest member of Collinder 69, a well-defined, compact open cluster at the center of the star forming region. Two other […]