Recent Talks

El Proyecto de SOLARNET se encarga del desarrollo de Unidades de Campo Integral (IFU) basadas en rebanadores de imagen para observaciones solares. El objetivo es alcanzar los requerimientos de EST en cuanto a resolución espacial y Field of View (FoV). La primera IFU desarrollada con un rebanador de imagen de 100 μm de ancho demostró la viabilidad de esta tecnología para espectropolarimetría solar. Ahora, para alcanzar el objetivo es necesario aumentar la resolución espacial y el FoV. Por ello, se han desarrollado dos nuevas IFUs que permitirán validar estos objetivos. Una está basada en tecnología de vidrio (igual que el actual) y el otro en tecnología metálica. Ambas alternativas tienen sus ventajas e inconvenientes y está todavía por confirmar si pueden cumplir los requisitos de EST, en términos de calidad de imagen. En esta charla nos pondremos al día del estado del proyecto y se presentará la última IFU con un rebanador de 35 μm que actualmente está siendo desarrollada. 

https://youtu.be/BJJWKgBeUPY

One prediction of ΛCDM is the existence of partially phase-mixed substructures from accreted dwarf galaxies in the Milky Way stellar halo. Substructure originating in a single accretion event can be readily identified as a tight cluster of stars in phase space with similar chemical properties. Recently, the discovery of the Gaia Sausage Enceladus (GSE) has revolutionised our understanding of the complex assembly of the Milky Way halo. We present a review of the chemistry that characterises the last major merger that happened to the Milky Way some 9-10 Gy ago.

Insights on the shape and nature of the ionizing continuum in astronomical objects are usually inferred via indirect methods as high energy photons are absorbed by our Galaxy. This talk will discuss the relevance of high ionization-potential coronal lines as unique tracers on the ionizing continuum  of active galactic nuclei (AGN), and of active black-hole in general.Focussing on AGN,  using bona-fide black-hole  masses from reverberation mapping and the strong infrared coronal line [Si vi] 1.96 um, a novel BH-mass scaling relation of the form log(M_BH) = (6.40 ± 0.17) − (1.99 ± 0.37)× log ([Si vi] / Brγ_broad) over  the BH mass interval, 10^6 − 10^8 Mo, is found. The dispersion of the relation is 0.47 dex, comparable with that of the canonical "M-sigma" relation.   Following on the thinaccretion disc approximation and after surveying a basic parameter space for coronal lines production, we believe a main driver of the relation is the effective temperature of the disc, which is effectively sampled by the [Si vi] 1.96 um coronal line. By means of CLOUDY photoionisation models, the observed anti-correlation appears formally in line with the thin disc prediction Tdisc prop M_BH^(-1/4).

Zoom:

https://rediris.zoom.us/j/5614942498
Meeting ID: 561 494 2498

YouTube:

https://youtu.be/lfYhJ0pMwTY

I will present the Cosmology and Astrophysics with MachinE Learning Simulations (CAMELS) project, whose main goal of the project is to provide theoretical predictions for observables as a function of cosmology and astrophysics by combining thousands of state-of-the-art cosmological hydrodynamic simulations with machine learning. I will first introduce the simulations and their characteristics. Next, I will present a few results from the CAMELS collaboration, such as the finding of a universal relation between subhalo properties, the usage of convolutional neural networks to marginalize over astrophysics effects at the field level, a constrain on the mass of the Milky Way and Andromeda using graph neural networks, and the prospects of inferring cosmological parameters with a single galaxy.

Join Zoom Meeting
https://rediris.zoom.us/j/81173800387?pwd=Q3hvV0trbnlXeTQ2SzZVS1JveGZZUT09
Meeting ID: 811 7380 0387
Passcode: 437953

YouTube: https://youtu.be/qCYFAh9te_Y

Galactic globular clusters have always been at the crossroad of several investigations
in both Stellar and Galactic Astrophysics. For long time, they have been considered
the prototypes of Simple Stellar Populations, and hence used for testing and calibrating
stellar evolutionary models as well as population synthesis tools. Nowadays, after the 
discovery of the presence of multiple stellar populations in almost all Galactic GCs, we know
that this assumption is no longer valid. The process(es) of formation and early evolution 
of these star clusters is (are) very far to be understood, and any scenario so far envisaged is
severely challenged by the pletora of empirical evidence collected till now. In the same time,
thanks to the availability of an impressive observational framework - collected by combining
kinematic measurements from Gaia mission, with data provided by large spectroscopic and 
photometric surveys -, GCs are playing a crucial role for our understanding of the
assembly history of the Milky Way.
We will review our present knowledge about these important stellar systems, discussing the 
several, open issues related to their formation/evolution, and discuss how we can use them
in our effort to depict the Milky Way assembly history.

Containers are portable environments that package up code and all its dependencies so that an application can run quickly and reliably from one computing environment to another. Most people are probably familiar with full virtualization environments (such as VirtualBox), so in this talk we will explain the main differences between full virtualization and containers (sometimes called light-weight virtualization), and when to use each.

At the same time, not all container technologies have the same goals and/or approaches. Docker is the most mature container offering, but it is geared mainly towards micro-services. Singularity is a newer contender, with an emphasis on mobility of compute for scientific computing. We will introduce both softwares, showing how to create and use containers with each of them, while discussing real-life examples of their use.

The lecture notes can be found here:
https://gitlab.com/makhlaghi/smack-talks-iac/-/blob/master/smack-13-docker.md

 ¿Cómo podemos saber si el instrumento que hemos diseñado es suficientemente seguro?

¿Quién debe realizar ese análisis?

¿Estamos dedicando suficientes recursos a la seguridad de las máquinas?

Durante la charla, intentaremos abordar estas y otras cuestiones sobre seguridad. Prometo no basar la charla en el repaso de normativa y leyes para no torturar demasiado (y por miedo a represalias), pero sí repasaremos el flujo de diseño que se debe seguir en los proyectos para obtener un sistema de seguridad adecuado al instrumento o máquina.

Unirse a la reunión Zoom

https://rediris.zoom.us/j/82384394724

In the local universe most of the stellar mass is in passive galaxies, where star formation is
absent or at very low levels. Understanding what are the mechanisms that have been
responsible for quenching star formation in galaxies, and transforming them into passive,
quiescent systems, is one of the main observational and theoretical challenges of extragalactic
astrophysics. I will give a brief overview of the several possible quenching causes and physical
processes that have been proposed so far, ranging from feedback from black hole accretion and
starburst activity, to effects associated with the large scale environment in which galaxies live.
Although most of these mechanisms and causes play a role in different classes of galaxies and
at different epochs, multi-band observations are providing growing evidences that just a few of
them play the key, dominant role.
I will conclude by providing prospects for further investigating these aspects and tackling open
questions with the next generation of observing facilities.

Mark I is a part of the origin of the IAC, operating in the El Teide Observatory since 1975, in three different locations until reaching the Solar Pyramid "van der Raay" in 1987. Every day, weather permitting, it has been providing precise measurements of the radial velocity of our star. It began to perform continuous daily observations from July 1984 and, until December 2020, 10169 out of 13408 possible days (76%) useful data has been gathered. Designed, updated, maintained and operated by the Helioseismology team at the IAC and the University of Birmingham (UK), more than 100 people, from TOTs and weekend fellows to professors, have contributed to this endeavour. It was a true pioneer, key in the birth and development of Helioseismology and Astroseismology as branches of modern Astronomy.

Mark I is a resonant scattering spectrophotometer that measures the radial velocity of integral sunlight using the KI-769.9 nm spectral line. It has been a pioneer and reference for calibration of other instruments: MarkII, IRIS, Cannon, Stellar, Space, BiSON, GOLF, which have also worked in different ground-based observatories and in space missions such as SoHO (1995-).

Its precision, in a single measurement of the solar radial velocity, is less than 1 m/s, and the one achieved so far is less than 1 cm/s at frequencies around 0.1 mHz (gravity modes zone) and less than 1 mm/s at 3 mHz (acoustic modes zone). It measured for the first time the spectrum of solar acoustic modes (from 1.8 to 4.2 mHz) of small degree (ℓ <= 3): their frequencies, amplitudes and lifetimes, their rotational splitting; also its variations with the cycle of solar activity. He has explored gravity modes, measured the spectrum's background, and determined the acoustic cut-off frequency in the solar photosphere. All this has led to numerous discoveries that have been published in around 40 doctoral theses at different universities and more than 600 papers in international journals and books. These works have been already cited around 10,000 times in scientific literature.

In this talk I will briefly review its history throughout more than 45 years, an entire academic life, and I will raise some suggestions on its scientific use from now on.