Recent Talks
List of all the talks in the archive, sorted by date.
Abstract
Although the name 'fundamental metallicity relation' (FMR) may sound a bit bombastic, it really represents a fundamental relation in the sense of revealing a fundamental process in galaxy formation. Numerical simulations predict that accretion of cosmic web gas feeds star formation in star-forming galaxies. However, this solid theoretical prediction has been extremely elusive to confirm. The FMR, i.e., the fact that galaxies of the same stellar mass but larger star formation rate (SFR) tend to have smaller gas-phase metallicity (Zg), is one of the best observational supports available yet. The talk will introduce the FMR and then present recent results of our group showing how the FMR emerges from a local anti-correlation between SFR and Zg existing in the disks of galaxies. Thus, understanding the FMR is equivalent to understanding why active star-forming regions tend to have low relative metallicity. The existence of the local anti-correlation SFR-vs-Zg is found by Sanchez-Menguiano+19 ApJ and Sanchez Almeida+18 MNRAS, whereas the equivalence between local and global laws is in Sanchez Almeida & Sanchez-Menguiano 19 ApJL.
Abstract
Supernova SN1987A in the Large Magellanic Cloud offers an unprecedented opportunity to tackle fundamental issues of supernova explosions: dust and molecule formation, interaction with the circumstellar medium, particle acceleration, pulsar formation, etc. Since 2011, instruments like ALMA have been fundamental for such endeavor. Tomographic techniques have recently permitted to obtain 3D-images of the molecular emission. High-resolution images of dust emission have recently been obtained. All those results, compared with predictions from hydro-dynamical simulations, are paving the way to a better understanding of supernovae explosions. In the talk, the main results will be highlighted with emphasis on the advances produced since 2017 in the understanding of the structure of the inner ejecta or debris.
Abstract
This talk looks at the challenges in developing instruments for extremely large telescopes. It then discusses the impact of these on the ELT first light instruments and their current status. The instruments are HARMONI, a visible - Near IR integral filed unit; MOARY/MICADO a multi-conjugate AO system and camera and METIS a thermal IR spectrometer and camera.
Abstract
The Time Inference with MUSE in Extragalactic Rings, TIMER, is a project dedicated to study the central regions
of 24 nearby galaxies with the integral field spectrograph MUSE. The spatial resolution of this instruments
allows the detailed study of the different structural components in these galaxies and, therefore, disentangle
their star formation histories, kinematics and dynamics of both, the gaseous and the stellar constituents.
In this talk, I will give an overview of the project as well as some details on how the dataset can be used for a plethora of scientific applications, like
understanding the stellar and AGN feedback, the role of primary and secondary bars, the dynamics of nuclear
spiral arms, barlenses, box/peanuts and bulges.
Abstract
The rotation rate of a cool star provides an additional method beyond the usual ones to characterize and understand its behavior. Increasingly large samples of rotation periods are now emerging from both ground- and space-based work. This talk will present some systematic behaviors of these rotation periods, including dependencies on age and mass, especially as probed by open cluster studies. The results suggest that it is often possible to derive an age for a cool star (and its planets) from such rotation period measurements, via a procedure called gyrochronology. This talk addresses the possibilities of this emerging area of work, and also certain complexities and cautions that should be considered in this Kepler, TESS, and soon, PLATO era.
Abstract
In this talk, I will present the highlights from our recent study of 22
local (z < 0.025) type-1 LINERs from the Palomar Survey, on the basis of
optical long-slit spectroscopic observations taken with TWIN/CAHA,
ALFOSC/NOT and HST/STIS (Cazzoli et al. 2018, MNRAS 480, 1106–1162).
In this study, we explored the AGN-nature of these type-1 LINERs by
studying the broad (BLR-originated) Hα component. Then, we derived
reliable interpretation for the different component of emission lines by
studying their kinematics and ionization mechanism. Finally, we studied
the neutral gas in the nuclei of these LINERs by modeling of the NaD
absorption.
Abstract
The Sloan Digital Sky Survey (SDSS) is one of the most successful and prolific projects in the history of Astronomy.
In its fifth iteration SDSS-V (2020-2025) will provide a more comprehensive, global picture of the local universe by
studying the interplay between galactic genesis, stellar and black hole processes, and the physics of the ISM. I will
review the main science goals of the project, the exciting new hardware being implemented (robot fibre positioner,
large IFU systems), and the operational challenges. As in its previous incarnations, SDSS-V remains committed to
providing high-quality data products for the astronomical and educational communities. I will discuss some of the
new ideas being developed for SDSS-V with regards to data reduction, release, archival, and visualisation.
Abstract
The advanced stages of high-mass stars are characterized by episodic mass loss shed during phases of instability. Key for assigning these stars a proper evolutionary state is to assess the composition and geometry of their ejecta alongside the stellar properties. I will speak about my work to increase the number of B[e] supergiants, Yellow Hypergiants and Luminous Blue variables in the Local Group by investigating circumstellar environments and exploring the evolutionary properties of high-luminous, dusty targets. By conducting and analyzing optical spectroscopy alongside fitting the spectral energy distribution, I derive stellar properties and infer the presence of circumstellar dust. In search of processed ejected material, modeling of the CO band heads in the K-band is further employed. Results of my work in M33 include the discovery of a strong Yellow Hypergiant candidate showing evidence of past eruption. Moreover, the insight into the surrounding molecular environment witnesses the presence of circumstellar/binary disks around post-supergiant/evolved stars. I highlight the importance of the infrared data to resolve the evolutionary status of massive stars and thus, to constrain the physics of the diverse pre-supernova stellar states. Finally, I will speak about my work at IAC regarding the photometric properties of OB stars in conjunction to the latest Gaia Data Release 2 and their possible link to the line-broadening status of the stars.
Abstract
Starlight principles and recommendations are brought together in the “Declaration in Defence of the Night Sky and the Right to Starlight” (“La Palma Declaration.” 2007), in which, in addition to the IAC, representatives of UNESCO, UNWTO, IAU, UNEP-CMS, CE, SCBD, COE, MAB and the Ramsar Convention all participated and launched Starlight as an international movement in defence of the sky by night and day and to treat it as a source of knowledge and culture that should be shared with society as a whole, promoting the dissemination of astronomy and sustainable, high-quality tourism in those places where the night sky is cared. The Starlight Reserves, Tourist Destinations and other modalities are scenarios that incorporate the observation of the sky as part of the natural, scenic, cultural and scientific heritage and encourage “Star Tourism”, promoting infrastructure, products, activities and training of specialized guides in the field of sustainable tourism. The Starlight Foundation has been selected to lead the UNWTO Affiliate Member Working Group on Scientific Tourism. Updated Starlight certifications and current projects will be summarized in this presentation.
Abstract
The SDSS Apache Point Observatory Galactic Evolution
Experiment (APOGEE) has
collected high resolution near-IR spectra of several hundred thousand stars
across the Milky Way. I'll describe some observational results about the
spatial variation of chemical abundances as a function of Galactocentric
radius and distance from the midplane, discussing mean abundances,
metallicity
distribution function, and the variation of abundance ratios of multiple
elements. Additional information related to stellar ages can be obtained
from [C/N] for red giant stars. Several lines of evidence suggest that
radial
migration has had a significant impact on the Galactic disk. The
observed patterns of
abundance ratios may provide observational constraints on
nucleosynthetic yields.
Upcoming talks
- Properties and origin of thick disks in external galaxiesDr. Francesca PinnaThursday January 16, 2025 - 10:30 GMT (Aula)
- Seminar by Luigi TibaldoLuigi TibaldoTuesday January 21, 2025 - 12:30 GMT (Aula)