Recent Talks

LiteBIRD is the next-generation CMB space mission designed to produce full-sky polarization maps with unprecedented sensitivity. Spain contributes to the scientific exploitation, to the data-processing centres that will support operations and analysis to the mission, and to the technological development of the payload through the Temperature Monitoring and Compensation System (TMCS). The TMCS is responsible for monitoring the instrument’s thermal environment, with particular focus on the sub-kelvin cryogenic stage that sets the operating temperature of the Transition Edge Sensor (TES) detectors. This stage operates near 100 mK, where the scientific requirements impose thermal stability at the level of a few micro-kelvin—or even fractions of a micro-kelvin—over the relevant time scales (<0.1uHz - 5Hz). Achieving such performance, while potentially compensating for temperature fluctuations induced by cosmic-ray impacts and sky-background variations on the focal plane, constitutes a major technical challenge. The ongoing prototyping activities are therefore centred on identifying the critical functions of the TMCS electronics, developing dedicated electronic designs for each of them, and validating their feasibility through targeted tests. A first complete readout chain has been implemented to characterise components, evaluate noise and stability performance, verify subsystem functionality, and determine the architectural refinements required for the next design iteration. This presentation will summarise the thermal and stability requirements of the LiteBIRD instrument, describe the architecture and expected performance of the TMCS readout electronics, and present the results obtained during the current validation campaign. Finally, the status and needs of the room-temperature and sub-kelvin test benches, as well as the key development activities planned for the coming months, will be outlined.

Oscillations of solar-like stars are thought to be stochastically excited, and following Lighthill, the primary excitation mechanism is often assumed to be quadrupolar turbulent Reynolds stresses, though other models for excitation have been proposed. Recently, techniques have been developed to measure the near field wavefronts emitted by individual solar acoustic sources. These techniques have been successfully applied to radiative magnetohydrodynamic simulations of the upper solar convection zone and lower solar atmosphere, and direct waveform fitting has been used to invert for the source properties. Efforts to extend these measurements to high spatial resolution, high temporal cadence solar observations are underway. In this talk we will summarize what the global p-mode spectrum suggests about the stochastic excitation of the solar acoustic oscillations, describe what we have learned about the excitation of acoustic waves recently from the numerical simulations, and outline an observational path to similar success with the real Sun.

Una de las principales limitaciones tanto del sistema LGS como de sus componentes es evitar las frecuencias propias que pudieran afectar al espejo primario de GTC, empeorando sus prestaciones. El objetivo de la presente charla es presentar los estudios analíticos, FEMs y resultados experimentales para las frecuencias propias del Banco Óptico del Sistema de Transferencia de la Estrella Guía Láser para GTC. Se hará hincapié en la cualificación de modelos de elementos finitos, así como una demostración práctica de las complicaciones que presenta el estudio dinámico de los sistemas.

The European Solar Telescope (EST) has completed the Preliminary Design Review (PDR) of its Single Conjugate Adaptive Optics (SCAO) system and real-time controller. We present an overview of the expected SCAO performance based on the consolidated preliminary design, including simulations of a dual-branch configuration at 500nm and 680nm. The results, obtained with the new open-source Solar Adaptive Optics Simulator (SAOS) and validated against DASP, also evaluate key error sources specific to solar observations. We summarise the performance of the proposed real-time controller, the Durham Adaptive Optics (DAO) platform, and the successful demonstration tests conducted with SAOS.

A lo largo del último año, el programa de la óptica adaptativa de GTC (GTCAO) ha experimentado un enorme avance. Los equipos de GRANTECAN y del IAC han estado trabajando juntos en GTC para mejorar la calidad óptica del telescopio, poner a punto el sistema de GTCAO e integrar el primer instrumento de alta resolución espacial, la cámara infrarroja GRANCAIN. Este enorme esfuerzo ha dado resultados y el pasado mes de abril se consiguieron las primeras imágenes de GTC, en banda K, en el límite de difracción, alcanzando un Strehl Ratio por encima del 60%.

En la presentación se resume el trabajo realizado en el cofaseo del telescopio con la imprescindible colaboración del equipo de Keck y TMT, el trabajo de integración y pruebas de GRANCAIN, y los resultados en cielo con GTCAO.

The ESAC Science Data Centre (ESDC) hosts the scientific  archives from the astronomy, planetary, heliophysics, and human and  robotic exploration missions from ESA. In particular, at the ESDC we host mirrors of the Hubble Space Telescope and the James Webb Space Telescope archives, as well as the main archives for many other astronomy missions such as Planck, Herschel, XMM-Newton and Euclid. These archives represent more than three decades of space‑based astronomy and their science archives offer tremendous potential for new discoveries. In addition to the archives, at the ESDC we have developed ESASky (sky.esa.int), a web application to discover astronomical data from ESA and other partner agencies and ground based observatories, and ESA Datalabs, a science platform that allow users to discover, access and analyze the data from these missions  on premises, without the need to download anything. In this presentation I will show how users of the eHST, eJWST and Euclid Data Space can take advantage of ESASky and ESA Datalabs science platform to implement and execute end‑to‑end research workflows. This is possible thanks to two very intuitive user interfaces that combine search tools to discover the  data from HST, JWST and Euclid,  analysis and calibration software for the case of JWST, and the necessary computational resources, all in the same data centre.

Scientific coffee will be served in the cafeteria at 12:30 BEFORE THE SEMINAR

FRACTAL S.L.N.E. es una empresa privada cuya historia comenzó en Los Realejos (Tenerife) en agosto de 2005. Tras casi una década de trabajo en GRANTECAN, sus dos fundadores decidieron emprender el reto de ofrecer servicios de ingeniería para desarrollar proyectos de instrumentación y software para la Astrofísica profesional. A lo largo de más de veinte años de actividad, FRACTAL ha colaborado con numerosos centros de investigación, universidades, observatorios y empresas tecnológicas que han depositado su confianza en nuestro trabajo. Nuestros clientes trabajan en España, en diversos países europeos, en Estados Unidos, México y China, así como en organizaciones internacionales de referencia en Astronomía como la European Southern Observatory. En esta charla resumiré las principales áreas de actividad y algunos de los proyectos más emblemáticos en los que hemos tenido la oportunidad de participar.

Dozens of gravitationally self-bound stellar groupings are known to orbit the halo of the Milky Way. At the faint end, some of these satellites are globular clusters: compact (few pc size), chemically homogeneous systems whose internal dynamics show no evidence for dark matter. Others, on the other hand, are dwarf galaxies: typically larger (~kpc size) systems with varied stellar populations and internal kinematics suggestive of the presence of large amounts of dark matter.  More recently, a number of satellites with properties straddling these two categories have been identified: they are compact in size, but fainter than traditional globular clusters or dwarf galaxies, and with velocity dispersions so low that only upper limits can be placed on their dark matter content. I will discuss the cosmological significance of these systems for the clustering of dark matter in the smallest scales, and for our understanding of the formation of the faintest galaxy systems in the Universe.