Recent Talks
List of all the talks in the archive, sorted by date.
Abstract
There is a "Warped side" of our universe, consisting of objects and phenomena that are made solely or largely from warped spacetime. Examples are black holes, singularities (inside black holes and in the big bang), and cosmic strings. Numerical-relativity simulations are revolutionizing our understanding of what could exist on our universe's Warped Side; and gravitational-wave observations (LIGO, VIRGO, LISA, ...) will reveal what phenomena actually do exist on the Warped Side, and how they behave.
Abstract
Over the next decade or so, the gravitational-wave window onto the Universe will be opened in four frequency bands that span 22 orders of magnitude: The high-frequency band, 10 to 10,000 Hz (ground-based interferometers such as LIGO and VIRGO), the low-frequency band, 10-5 to 0.1 Hz (the space-based interferometer LISA), the very-low frequency band, 10-9 to 10-7 Hz (pulsar timing arrays), and the extremely-low-frequency band, 10-18 to 10-16 Hz (polarization of the cosmic microwave background). This lecture will describe these four bands, the detectors that are being developed to explore them, and what we are likely to learn about black holes, neutron stars, white dwarfs and early-universe exotica from these detectors' observations.
Abstract
Spectral energy distributions (SEDs) of the central few tens of parsec region of some of the nearest active galactic nuclei (AGN) are presented. Peering into the nucleus at these scales, it is found that the intrinsic shape of the spectral energy distribution of an AGN and inferred bolometric luminosity largely depart from those currently on use, mostly extracted from low resolution data. The shape of the SED is different and the AGN luminosities can be overestimated by up to two orders of magnitude if relying on IR satellite data.Although the shape of these SEDs are currently limited by the availability of high angular resolution data beyond ~20 μ, a prediction from this work is that a major contribution from cold dust below 100 K to these cores is not expected. Over the nine orders of magnitude in frequency covered by these SEDs, the power stored in the IR bump is by far the most energetic fraction of the total energy budget in these cores, accounting for more than 70% of the total.
Abstract
El curso tendrá un carácter eminentemente práctico. Tras una breve serie de presentaciones sobre el proyecto Observatorio Virtual y las herramientas de análisis existentes se procederá al desarrollo de casos científicos reales utilizando una metodología VO. El desarrollo de estos casos científicos se realizará bajo la supervisión de personal del Observatorio Virtual Español.
Abstract
El curso tendrá un carácter eminentemente práctico. Tras una breve serie de presentaciones sobre el proyecto Observatorio Virtual y las herramientas de análisis existentes se procederá al desarrollo de casos científicos reales utilizando una metodología VO. El desarrollo de estos casos científicos se realizará bajo la supervisión de personal del Observatorio Virtual Español.
Abstract
El curso tendrá un carácter eminentemente práctico. Tras una breve serie de presentaciones sobre el proyecto Observatorio Virtual y las herramientas de análisis existentes se procederá al desarrollo de casos científicos reales utilizando una metodología VO. El desarrollo de estos casos científicos se realizará bajo la supervisión de personal del Observatorio Virtual Español.
Abstract
Despite speculation that both starburst and nuclear activity in galaxies may be intimately linked via the common triggering mechanism of mergers and interactions, very little is known about the true nature of the link. Thus, the role of AGN in the formation and evolution of galaxies is still not well established. I will present deep Gemini/GMOS imaging observations which are used to investigate the triggering mechanism(s) in a complete sample of radio-loud AGN for which, uniquely, we have quantified the level of both the AGN and star formation activity. I will show results on the proportion of powerful radio galaxies triggered in galaxy mergers and also on the link between the degree of star formation/AGN activity and the interaction status of the host galaxies.
Abstract
El curso tendrá un carácter eminentemente práctico. Tras una breve serie de presentaciones sobre el proyecto Observatorio Virtual y las herramientas de análisis existentes se procederá al desarrollo de casos científicos reales utilizando una metodología VO. El desarrollo de estos casos científicos se realizará bajo la supervisión de personal del Observatorio Virtual Español.
Abstract
El curso tendrá un carácter eminentemente práctico. Tras una breve serie de presentaciones sobre el proyecto Observatorio Virtual y las herramientas de análisis existentes se procederá al desarrollo de casos científicos reales utilizando una metodología VO. El desarrollo de estos casos científicos se realizará bajo la supervisión de personal del Observatorio Virtual Español.
Abstract
We present the results of our systematic search for optically elusive, but intrinsically luminous buried AGNs in >100 nearby (z < 0.3) luminous infrared galaxies with L(IR) > 1011 L⊙, classified optically as non-Seyferts. To disentangle AGNs and stars, we have performed (1) infrared 2.5-35 μ low-resolution (R ~ 100) spectroscopy using Subaru, AKARI, and Spitzer, to estimate the strengths of PAH (polycyclic aromatic hydrocarbon) emission and dust absorption features, (2) high-spatial-resolution infrared 20 micron imaging observations using Subaru and Gemini, to constrain the emission surface brightnesses of energy sources, and (3) millimeter interferometric measurements of molecular gas flux ratios, which reflect the physical and chemical effects from AGNs and stars. Overall, all methods provided consistent pictures. We found that the energetic importance of buried AGNs is relatively higher in galaxies with higher infrared luminosities (where more stars will be formed), suggesting that AGN-starburst connections are luminosity dependent. Our results might be related to the AGN feedback scenario as the possible origin of the galaxy down-sizing phenomenon.Upcoming talks
- Coloquio con Isabel Pérez Grande (AEE)Dr. Isabel Pérez GrandeTuesday November 26, 2024 - 10:30 GMT (Aula)
- Revisiting mass transfer and accretion in symbiotic binaries in the Gaia eraDr. Jaroslav MercThursday November 28, 2024 - 10:30 GMT (Aula)
Recent Colloquia
Recent Talks
