Recent Talks

The Square Kilometre Array is intended to be the centimeter- and meter-wavelength telescope for the 21st Century. Originally proposed as the "hydrogen telescope," the science case is now recognized to be much broader, and the SKA will address fundamental questions in astrophysics, physics, and astrobiology. The international science community has developed a set of Key Science Programs: (1) Emerging from the Dark Ages and the Epoch of Reionization; (2) Galaxy Evolution, Cosmology, and Dark Energy; (3) The Origin and Evolution of Cosmic Magnetism; (4) Strong Field Tests of Gravity Using Pulsars and Black Holes; and (5) The Cradle of Life & Astrobiology. I highlight how the SKA's Key Science Programs will be an integral component of the multi-wavelength, multi-messenger frontiers for astronomy and how the science pathfinding for the SKA is beginning now.

The vision for the use of the WHT in the coming decade is taking shape.   A key element is the construction and deployment of WEAVE, a wide-field massive-multiplex spectrograph.  With 1000 fibres and spectral resolutions of 5000 and 20000, the opportunities for discovery are tremendous.  Three key fields will be: Milky-Way and Local Group archaeology linked to the   Gaia mission; cosmology redshift surveys; and galaxy evolution studies linked to photometric surveys such as VISTA, UKIDSS, LOFAR, EUCLID, and  others. IAC has the opportunity to get involved in this important instrument for ORM from the beginning.

With the discovery of several massive, young clusters in the last five years, the area around the base of the Scutum-Crux arm (around l=28) has become one of the more intense stellar formation areas in the whole Galaxy. This is not totally unexpected, as it is just there where it was predicted that the long bar of the Milky Way would come into contact with the disk, triggering stellar formation. With this talk we review all these evidences and we bring others into light, as we try to obtain a clearer picture of what is happening in these areas and what does it tell us about the inner structure of the Galaxy, particularly of the bulge+bar complex.

In recent years it has become clear that stars can migrate across large regions of the disk without increasing substantially the velocity
dispersion.  I review the theory and consequences of migration and discuss
some of the evidence supporting the occurrence of stellar migration,  including in the Milky Way's thick disk.

The Kepler spacecraft is providing photometric time series with micromagnitude precision for thousands of variable stars. The continuous time-series of unprecedented timespan open up the opportunity to study the pulsational variability in much more detail than was previously possible from the ground. We present a first general characterization of the variability of A-F type stars as observed in the Kepler light curves of a sample of 750 candidate variable A-F type stars, and investigate the relation between gamma Doradus, delta Scuti, and hybrid stars. Our results suggest a revision of the current observational instability strips, and imply an investigation of pulsation mechanisms to drive hybrid pulsations.

The 2nd generation VLT instrument Multi Unit Spectroscopic Explorer(MUSE) is going to be an integral field spectrograph with wide field of view and high spatial sampling. It is currently being built by a European consortium to see first light end of 2012. I will describe instrumental properties, show some details of the optomechanical design, present the data processing, and give some examples for possible scientific use.

I will review some theoretical ideas in Cosmology different to the standard "Big Bang": the Quasi-steady State model, Plasma Cosmology model, non-cosmological redshifts, alternatives to non-baryonic dark matter and/or dark energy, and others. Some open problems of Cosmology within the standard model will also be summarized.

We have selected the Galactic HII region M43, a close-by apparently spherical nebula ionized by a single star (HD37061, B0.5V) to investigate several topics of recent interest in the field of HII regions and massive stars. We perform a combined, comprehensive study
of the nebula and its ionizing star by using as many observational constraints as possible. For this study we collected a set of high-quality observations, including the optical spectrum of HD3706, along with nebular optical imaging and long-slit spatially resolved spectroscopy. On the one hand, we have carried out a quantitative spectroscopic analysis of the ionizing star from which we have determined the stellar parameters of HD37061 and the total number of ionizing photons emitted by the star; on the other hand, we have done a
empirical analysis of the nebular images and spectroscopy from which we have find observational evidence of scattered light from the Huygens region (the brightest part of the Orion nebula) in the M43 region. We show the importance of an adequate correction of this scattered light in both the imagery and spectroscopic observations of M43 in accurately determining the total nebular Halpha luminosity, the nebular physical
conditions. and chemical abundances. We have computed total abundances for three of the analyzed elements (O, S, and N), directly from
observable ions (no ionization correction factors are needed). The comparison of these abundances with those derived from the spectrum of the Orion nebula indicates the importance of the atomic data and, specially in the case of M42, the considered ionization correction factors.

In the first part of this talk I will present a historical review of the CMB observations, one of the most powerful cosmological probes. Following the first talk of this series, where Jose Alberto described the basic parameters that define the standard cosmological model, I will here summarize the constraints to these parameters that have been derived from these observations. I will also describe the current challenges in this field, in particular the detection of the inflation's B-mode signal through CMB polarization observations, as well as the experiments that have been developed worldwide to this aim, including IAC's QUIJOTE. In the second part, I will focus on the so-called ``missing baryon problem'', i.e. the fact that the half of the expected baryon content of the local universe remains yet undetected. I will describe the theoretical studies that provide hints on where these baryons could be located, and the observational efforts that have been undertaken in this regard.