Recent Talks

X-ray binaries (XRBs) are binary systems where a compact object, either a black hole or a neutron star, accretes matter from a stellar companion via an accretion disc. As this material spirals in, it heats up and emits X-rays, typically exhibiting transient outburst behaviour.

During these outbursts, XRBs often transition between hard states (dominated by inverse Comptonization in a hot-electron corona) and soft states (where thermal emission from the disc prevails). In the hard states, XRBs display strong variability across multiple timescales, frequently featuring quasi-periodic oscillations (QPOs).

To probe these fast dynamics, we employ spectral-timing Fourier techniques, which allow us to infer the geometry of the accretion flow and the mechanisms governing radiation propagation in the vicinity of the compact object, crucial information not directly accessible through the stationary spectrum alone.

In this talk, I will delve into the spectral-timing phenomenology of XRBs and present the insights gained from applying a time-dependent Comptonization model, aiming to deepen our understanding of the state transition and outburst evolution in these complex systems.

EL IAClink establecerá instalaciones de vanguardia en los Observatorios del Roque de los Muchachos (La Palma) y del Teide (Tenerife) para avanzar significativamente en la investigación y el desarrollo de las comunicaciones ópticas clásicas y cuánticas. Aprovechando la configuración atmosférica horizontal de 144 km única en el  mundo —comparable al trayecto visual de los satélites en órbita baja cuando están en el horizonte—, las instalaciones proporcionarán un entorno excepcional para probar la viabilidad y eficacia de los enlaces ópticos bajo condiciones de turbulencia significativa. Este sitio, con su alta disponibilidad de condiciones atmosféricas óptimas, tanto de día como de noche, es ideal para simulaciones realistas y experimentación avanzada, maximizando las posibilidades de éxito en pruebas críticas de comunicación. El uso histórico de este enlace, incluidas contribuciones a investigaciones galardonadas con el Premio Nobel, como las del físico Anton Zeilinger en 2022, subraya su valor único para la comunidad científica global. Al aprovechar estas capacidades, la infraestructura no solo fomentará avances tecnológicos, sino que también consolidará la posición de España como líder en investigación de comunicaciones ópticas y cuánticas a nivel internacional.

In the last years, ground-based and space observations are bringing a wealth of constraints on the chemical composition of exoplanet atmospheres. Chemical models are particularly useful because they provide the theoretical framework to interpret these observations and make new predictions. I will describe how such models are built and discuss some recent efforts aimed to provide a more accurate description of the atmospheric composition, with emphasis on the mutual influence of temperature and disequilibrium composition, the quantification of abundance uncertainties, and the variation of the composition as a function of longitude.

Tras un año desde su construcción, se empezaron a realizar algunas mejoras en la estructura, sensores y equipamiento del EMO-1, consiguiendo aumentar la seguridad y capacidades de este pequeño observatorio personal.

En la charla se recorrerán todos los cambios implantados y los resultados obtenidos a lo largo del año, tanto antes del cambio como después de los mismos, y mejoras futuras.

I will present ATLAS-Teide, the new robotic facility of the Asteroid Terrestrial-impact Last Alert System (ATLAS), built and installed by the IAC at the Teide Observatory in mid-January 2025. ATLAS-Teide is part of the IACs Strategic Plan of the Canary Observatories, supported by projects EQC2021-007122-P and ICT2022-007828, both funded by the European Union – NextGenerationEU. The system operates within the global ATLAS network under a collaborative agreement between the IAC and the University of Hawaii, covering both operations and scientific exploitation.

ATLAS is one of the most successful planetary-defense early-warning projects. The network currently includes four 50-cm Wright–Schmidt telescopes in Hawaii, Chile, and South Africa. Each unit surveys roughly a quarter of the night sky, imaging each field four times per night to V ~ 19.5, and is designed to detect ~20 m impactors days in advance and ~100 m objects weeks ahead.

ATLAS-Teide is the fifth ATLAS unit and introduces a cost-effective, modular design based on commercial off-the-shelf components. Each module combines four Celestron RASA 11 telescopes on a PlaneWave L-550 direct-drive equatorial mount with QHY600PRO CMOS cameras sharing a common field. A single module delivers the performance of a 56-cm aperture with a 7.5 deg2 field of view and 1.26 arcsec/pixel scale. The full facility comprises four modules in a roll-off-roof building, replicating the survey capability of existing ATLAS units-covering ~6000 deg2 four times per night with 30-second exposures to V ≈ 20.2. ATLAS-Teide is already providing high-cadence observations, reporting astrometry for thousands of asteroids nightly, discovering new NEAs and transients (including supernovae). I will also present first scientific results from the facility.

The discovery of dark matter (DM) followed cosmic gravitational observation (Zwicky, 1933), which remains inconsistent within known physics. Solar system observables exhibit unexpected planetary dependencies, even though no remote force beyond gravity exists. The question arises whether persisting local mysterious / anomalous/ … observations are signals from the dark sector. Gravitational focusing of DM streams should result to short focal ranges since the impact goes with 1/(speed)². Also, the inner mass distribution of solar system bodies can perform as gravitational lenses for streaming DM with flux amplification up to ~10⁹ x, compared to few % for isotropic DM. The analysis of a number of observations from near outer space fits in our streaming DM scenario.

Using measurements of cosmic positrons, the same analysis points to DM with the positrons being secondaries of parent DM. New direct measurements of cosmic rays can validate the first result. The telescopes in Tenerife might have relevant data worth re-analyzing them. An exciting Endeavor!

En esta presentación se describe el proceso de verificación realizado a los modelos de ingeniería de las monturas opto-mecánicas de la IPO, con el fin de asegurar el cumplimiento con los requisitos del subsistema. Para ello, se presentan las pruebas individuales de alineamiento mecánico y desempeño óptico para las monturas de los toroides de la escala 10mas de HARMONI, tanto a temperatura ambiente como a temperaturas criogénicas.

El Departamento de Electrónica del IAC ha desarrollado un Sistema de Adquisición de Datos embebido de alto rendimiento (eDAS) para realizar la lectura de una matriz MKIDs y llevar a cabo procesamiento digital de señal en tiempo real a nivel de hardware. El eDAS ha sido desarrollado utilizando el kit de evaluación Zynq UltraScale+ RFSoC ZCU111 y PYNQ. El objetivo final es poder detectar cambios en la amplitud y la fase de la señal del MKID cuando un fotón llega al detector, con el fin de observar la firma de un único fotón. Aunque el sistema eDAS aún está en desarrollo, actualmente se ha implementado un canalizador (banco de filtros polifásico + FFT) en la cadena de adquisición de datos. En este momento, se está implementando una generación de peine de frecuencias basada en hardware para excitar los detectores.

Lambda Cold Dark Matter (LCDM) is the most successful theory for the formation of structure in the Universe. Although its predictions have been verified on large scales, they are still contested on the scale of dwarf galaxies, whose dynamical properties are often cited as evidence for the need to revise some of LCDM’s basic tenets. In this context, I will discuss the recent discovery of the faintest galaxies known to date, and how their properties may be used to place constraints on the clustering of dark matter on the smallest galactic and sub-galactic scales, as well as on the viability of some of the proposed alternatives to LCDM.