Latest talks

List of all the talks in the archive, sorted by date.


Video
Thursday September 29, 2016
Dr. Fabian Schneider
Univeristy of Oxford

Abstract

Approximately 10 per cent of massive OBA main-sequence (MS) and pre-MS stars harbour strong, large-scale magnetic fields. At the same time, there is a dearth of magnetic stars in close binaries. A process generating strong magnetic fields only in some stars must be responsible and several channels for the formation of magnetic massive stars have been proposed. In this talk, I will present recent results on the origin and evolution of such strong surface magnetic fields. Regarding the origin, mergers of MS and pre-MS stars have been proposed to form magnetic stars and I will highlight a method to probe this hypothesis observationally. Applying this new method to two magnetic massive stars, we find that they are indeed consistent with being MS merger products. Utilising a large sample of magnetic and non-magnetic OB stars, I will show that there is a dearth of evolved magnetic stars that suggests that magnetic fields disappear over time. I will argue that this is most likely caused by decaying magnetic fields.


Video
Tuesday September 13, 2016
Dr. Marc Balcells
ING

Abstract

An exciting series of changes are taking place at the venerable WHT and INT on La Palma. WEAVE, the next generation multi-fibre spectrograph is being completed for the WHT prime focus. Once built, it will carry out massive surveys of stars, the Milky Way, galaxy evolution and cosmology. At the INT, the HARPS3 high-resolution stabilized spectrograph is being built. It will provide the ING communities with a world-class exoplanet research tool. This talk will address the observing opportunities brought by these two instruments, their development calendars, and ING’s plans to retain additional instrumentation for the open time. I will describe how the telescopes will be operated, both in the survey time and the open, TAC time.


Video
Monday September 12, 2016
Mr. Joseph Putko, Ms. Martyna Chrulinska, Mr. Antoni Ramos Baudes, Mr. Rafel Luque Ramírez, Mr. Roke Cepeda Arroita and Mr. Pablo Doña Girón

Abstract


Video
Monday September 5, 2016
Dr. Matteo Monelli, Mr. Jorge A. Pérez
Instituto de Astrofísica de Canarias

Abstract

In coincidence with the announcement of the call for proposal of the Spanish night CAT for semester 2017A, we present the new web page OOCC. This is the new astronomer portal of the IAC, and it targets the Spanish community with all the necessary information to access and observe with any telescope at both Observatorios Astronomicos de Canarias, that is the Observatorio del Teide and the Observatorio del Roque de los Muchachos. The new portal, developed by the IAC Telescope Operation Group in agreement with the Presidents of both the night and the solar CATs, supersedes the old www.iac.es/cat and www.iac.es/telescopes pages. In this talk we will present the most important aspects and possibilities of the portal.


Video
Friday September 2, 2016
Prof. Jifeng Liu
National Astronomical Observatories of the Chinese Academy of Sciences

Abstract

While ultraluminous supersoft X-ray sources (ULSs) bear features for intermediate mass black holes or very massive white dwarfs possibly close to Chandrasekhar mass limit, our recent discovery of processing relativistic baryonic jets from a prototype ULS in M81 demonstrate that they are not IMBHs or WDs, but black holes accreting at super-Eddington rates. This discovery strengthens the recent ideas that ULXs are stellar black holes with supercritical accretion, as demonstrated in the case of M101 ULX-1, and provides a vivid manifestation of what happens when a black hole devours too much, that is, it will generate thick disk winds and fire out sub-relativistic baryonic jets along the funnel as predicted by recent numerical simulations. 


Video
Friday September 2, 2016
Prof. Gang Zhao
National Astronomical Observatories of China

Abstract

The National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) was officially founded in April 2001 through the merger of several unites and was headquartered in Beijing, which was formerly called the Beijing Astronomical Observatory established in 1958. Aiming at the forefront of astronomical science, NAOC conducts cutting-edge astronomical studies, operates major national facilities and develops state-of-the-art technological innovations in China.  NAOC is one of the most important institutes for Astronomy in Chinese Academy of Sciences (CAS)  system, as well as in the whole country. I will briefly introduce NAOC, including the facilities, research and the international collaborations.


Video
Thursday August 11, 2016
Dr. Devika Kamath
Universidad de Leuven

Abstract

 In this talk I will present the our work on an exotic group  
of evolved objects: post-AGB and post-RGB stars and the excellent  
constraints they provide for single and binary star evolution and  
nucleosynthesis. These objects have also revealed new evolutionary  
channels and AGB nucleosynthesis which is vital for understanding the  
complex chemical evolution of our Galaxy as well as external galaxies.

Video
Thursday July 28, 2016
Dr. Raúl Angulo
CEFCA

Abstract

Numerical simulations have played a crucial role in the development of modern
cosmology and in the establishment of LCDM. In this talk, I will review the main 
results and the fundamental assumptions behind those dark matter simulations. 
I will focus on the internal structure of halos and report on recent results on the 
formation and evolution of the very first halos to form in cold dark matter cosmologies. 
Then, I will discuss on recent attempts to model and study dark matter in the 
continuum limit. I will show how such methods help to overcome known problems 
of N-body simulations, and also how it is possible to get new insights into dark 
matter dynamics.

Video
Thursday June 30, 2016
Dr. Taketo Nagasaki
KEK Japan

Abstract

We propose ground-based monitoring system for atmospheric water vapor based on wide-range spectra at 20 – 30 GHz and 50 – 60 GHz ranges. It  observes in these microwave range and estimates the thermodynamic environments in the atmosphere. These information can determine short-term forecasting and now casting of severe storms. Our system can catch rapid increase of water vapor before clouds generation. We employ cold receiver system to achieve a system temperature below the atmospheric radiations. We will present overview of the system, including status of development, and results of long-term monitoring in outside.

Video
Thursday June 23, 2016
Dr. Sébastien Comerón
University of Oulu

Abstract

The disc of galaxies is made of the superposition of a thin and a thick disc. Thick discs are seen in edge-on galaxies as excesses of light a few thin disc scale-heights above the mid-plane. Star formation occurs in the thin discs whereas thick discs are made of old stars. The formation mechanisms of thick discs are under debate. Thick discs might have formed either at high redshift on a short time-scale or might have been built slowly over the cosmic time. They may have an internal or an external origin. To solve the issue of the thick disc origin we studied the kinematics and the stellar populations of the nearby edge-on galaxies ESO 533-4 and ESO 243-49. We present the first Integral Field Unit (IFU) spectroscopy works with enough depth and quality to study the thick discs. This was done with VIMOS@VLT and MUSE@VLT.

Our results point that thick discs formed in a relatively short event at high redshift and that the thin disc has formed afterwards within it. We also find that the thick disc stars have an internal origin as opposed to have their stars accreted during encounters. The work regarding ESO 533-4 has recently been published in Comer?n et al. 2015, A&A, 584, 34.



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