Recent Talks

The tidal tails of stellar clusters are an important tool for studying the clusters’ birth conditions, their evolution, coupling, and interaction with the Galactic potential, and to understand how field stars populate the Milky Way. Thanks to Gaia, much progress has been accomplished in finding tails of open clusters. We will show here that the physical size of such tidal tails is larger than previously thought. Their identification requires combining the sophisticated analysis of the Gaia catalogue using machine learning techniques to the use of N-body simulations and the new compact convergent point method. We will highlight recent results about the tails of the Hyades and of NGC 752, which extend over several hundreds of parsecs and present puzzling asymmetries that likely provide constraints on the potential of Milky Way. Finally, we will also present the extension of our studies to a large ensemble of open clusters and show how our analysis opens a completely new window on the study of open clusters, whose potential will be fully unleashed with future Gaia data releases.

Vimos Public Extragalactic Redshift Survey (VIPERS) is a spectroscopic survey designed to  investigate the spatial distribution of ~90k galaxies on redshift 0.4<z<1.2. The catalogue of spectroscopic observations, combined with auxiliary photometric data, is perfect for evolutionary studies of different types of galaxies. But also for tracing rare objects. One of them are the so-called “red nuggets”, progenitors of the most massive galaxies in the local Universe.  The discovery of red nuggets - highly massive, passive and extremely compact galaxies  -  at high redshift challenged the leading cosmological models, as they do not fit into the evolutionary paths of passive galaxies. Taking into account  that  the galaxies' mergers are stochastic events, it is possible that some red nuggets  remain relatively unaltered for billions of years. Those survivors constitute a group of unique galaxies in the local Universe,  commonly named “relics”. Despite numerous studies dedicated to red nuggets and relics, the link between the population of compact, massive, passive galaxies in the early Universe and their remnants in the local Universe, is still poorly understood.

In my talk I  will present the first spectroscopically selected catalogue of red nuggets at the intermediate redshift.  It is the most extensive catalogue of this kind of galaxies above redshift z > 0.5.  Selected under the most strict criteria, the group of 77 objects consists of a statistically important sample, which allows for analysis of physical properties of those rare passive giants. I will discuss the influence of compactness criteria on the sample size. Moreover I will present  VIPERS red nuggets number densities and discuss the environmental preferences of those exceptional galaxies.

Algunas palabras pueden ser seductoras y llegar a impulsar grandes hazañas, o pueden herir y, por despecho, motivar enormes esfuerzos, mover personas y sus creencias y con ellas arrastrar a las naciones. Un grupo de hombres, motivados por estas palabras, se enfrentaron a sus circunstancias y cruzaron las fronteras del mundo conocido, transformando la realidad.

Hubo dos viajes de exploración que consolidaron un imperio y un modelo socio–político y económico. En 1969 el hombre pisó la Luna y en 1519 navegó alrededor de la Tierra. Lejanos en el tiempo, estos viajes de exploración guardan mucho en común.

Hablar de la carrera espacial —en especial el viaje del hombre a la Luna— es también hablar de la Guerra Fría; de un enfrentamiento entre dos modelos políticos y económicos, antagónicos entre sí, liderados por la Unión Soviética y los Estados Unidos de América, en busca de la hegemonía geopolítica del planeta. Pero esa historia no era nueva. Quinientos años antes, España y Portugal, dos imperios nacientes, compitieron, en circunstancias muy parecidas, por el control de las rutas comerciales a Oriente. Su rivalidad los llevó a circunnavegar la Tierra, a ocupar un puñado de islas y a dominar el mundo conocido.

El Telescopio Solar Europeo espera alcanzar el diseño preliminar de todo el telescopio en 2023. Algunos subsistemas han pasado la Revisión de Diseño Preliminar (PDR) como es el caso de la Estructura del Telescopio, la Cubierta y Pilar, subsistemas en los que se centrará este seminario repasando su estado actual y sus prestaciones principales, así como los análisis y test con los que se han comprobado dichas prestaciones.

Enlace de youtube:

https://youtu.be/o9UwtmJL1IY

The formation of the first galaxies in the Universe is the new frontier of both galaxy formation and reionization studies. In fact, we will soon directly observe primeval galaxies thanks to the James Webb Space Telescope, and witness the reionization process through 21cm intensity mapping experiments. This unique moment in human history creates a fierce new challenge, i.e. to simultaneously understand in a unique and coherent picture the processes of galaxy formation and reionization, and – crucially – their connection. The latter, in particular, has escaped past numerical efforts. In this talk I will present the first results on this front from an years-long effort geared toward achieving such comprehensive picture, culminated in the Thesan suite of cosmological radiation-magneto-hydrodynamical simulations. I will briefly introduce the features of Thesan, highlighting the successes and failures of its physical model. Thesan produces realistic galaxy populations thanks to state-of-the-art physics, including self-consistent dust production+destruction and radiation transport. I will then show how Thesan can, for the first time, reproduce the connection between IGM and galaxies, as measured from the modulation of the Lyman-alpha flux around galaxies. Finally, I will chart the way forward towards and even deeper understanding of the emergence of the first structures in the Universe.

En esta sesión, cada uno/a de los/as becarios/as de desarrollo tecnológico de la convocatoria de 2022 hará una breve exposición del trabajo realizado durante los tres meses de duración de la beca:

10.00 - 10.10: Diego Portero Rodriguez: "Diseño de un circuito integrado analógico con una tecnología microelectrónica CMOS"

10.10 - 10.20: Elena Reyes Rodriguez: “Desarrollo y diseño óptico de un sistema de comunicaciones ópticas de distribución de clave cuántica QKD en protocolo BB 84 y un sistema de comunicaciones ópticas clásicas”

10.20 - 10.30:  Sara Muñoz Torres: “ Puesta en funcionamiento, pruebas y puesta a punto del sistema de adquisición de datos (SAD) para detectores MKIDs de LISA”

10.30 - 10.40: Daniel Pascual Rios: “Diseño, fabricación e integración del espectrómetro de microondas de Tenerife (TMS) y montaje, integración, verificación y comisionado del instrumento multifrecuencias mejorado (MFI2), que operaran en condiciones ambientales y criogénicas"

10.40 - 10.50: Guillermo Fuentes Morales: “Diseño del software para la simulación de la estrategia de optica adaptativa del telescopio solar europeo"

10.50 - 11.00: Victoria Vera Cañete: “Calibración de dos maquinas de recubrimientos ópticos del IAC"

11.00 - 11.10: Carlos Marrero De la Rosa: “Desarrollo de software de un modulo procesado para la utilización de la cámara plenóptica en óptica adaptativa, que se integre en el simulador DASP y en el controlador de tiempo real DARC”

Massive stars (at least eight times as massive as the Sun) possess strong stellar winds driven by radiation. With the advent of the so called MiMeS collaboration, an increasing number of these massive stars have been confirmed to have global magnetic fields. Such magnetic fields can have significant influence on the dynamics of these stellar winds which are strongly ionized. Such interaction of the wind and magnetic field can generate copious amount of X-rays, they can spin the star down, they can also help form large scale disk-like structures. In this presentation I will discuss the nature of such radiatively-driven winds and how they interact with magnetic fields.

https://youtu.be/jKmifm17bno

The first Gigayears of our Galactic halo can be probed by using ancient stellar populations as traced by RR Lyrae stars. Today, with the advancement in our knowledge of RR Lyrae properties belonging to the Halo and to Milky Way satellite systems (Globular clusters and dwarf galaxies) we are able
to provide solid constraints on the link between these stellar systems. Here, we present some recent results concerning the Halo formation by using a detailed evolutionary analysis of RR Lyrae stars for which chemical abundances are available.

Cosmological observations (redshifts, cosmic microwave background radiation, abundance of light elements, formation and evolution of galaxies, large-scale structure) find explanations within the standard Lambda-CDM model, although many times after a number of ad hoc corrections. Nevertheless, the expression ‘crisis in cosmology’ stubbornly reverberates in the scientific literature: the higher the precision with which the standard cosmological model tries to fit the data, the greater the number of tensions that arise. Moreover, there are alternative explanations for most of the observations. Therefore, cosmological hypotheses should be very cautiously proposed and even more cautiously received.

There are also sociological and philosophical arguments to support this scepticism. Only the standard model is considered by most professional cosmologists, while the challenges of the most fundamental ideas of modern cosmology are usually neglected. Funding, research positions, prestige, telescope time, publication in top journals, citations, conferences, and other resources are dedicated almost exclusively to standard cosmology. Moreover, religious, philosophical, economic, and political ideologies in a world dominated by anglophone culture also influence the contents of cosmological ideas.

Astrophysical observations at (sub)mm wavelengths (from ~300 micron to ~3mm)
allow us to study the cold and dense material in the Universe, hence probing
the formation of stars and planets, and the interstellar and circumgalactic
medium within galaxies across cosmic time. The current generation of
15m-class single-dish telescopes has delivered some of the first surveys at
(sub)mm wavelengths, allowing to go far beyond the previously optical-biased
view of the Universe. Follow-up observations with interferometers then
revealed in exquisite detail the morphology and kinematics of such (sub)mm
sources. However, it is now clear that without a transformative change in
the capabilities of single-dish facilities in the 2030s, interferometers
will soon become source-starved. The current generation of 15m-class single-
dish telescopes, with their limited fields of view, spatial resolutions, and
sensitivities, can only reveal the "peak of the iceberg" of the (sub)mm
source population, both for Galactic and extragalactic studies. These
limitations cannot be fully mitigated by interferometers, which are all
intrinsically affected by a low mapping speed and by the loss of diffuse
extended signals. The Atacama Large Aperture Submillimeter telescope
(AtLAST) project is a concept for a 50m diameter single dish observatory to
be built near the ALMA site. With its extremely large field of view (the goal
is ~2 degrees), spatial resolution (up to ~1'' at 350 micron) and sensitivity
to both point sources and large-scale structures, AtLAST will be
transformational for all fields of astronomy in the 2030s. In this talk I
will describe the EU Horizon2020-funded project that aims to deliver a
comprehensive design study for such a next-generation single-dish facility.