Recent Talks

The cosmological large-scale structure encodes a wealth of information about the origin and evolution of our Universe. Galaxy redshift surveys provide a 3-dimensional picture of the luminous sources in the Universe. These are however biased tracers of the underlying dark matter field. I will discuss the different components which are relevant to model galaxy bias, ranging from deterministic nonlinear, over non-local, to stochastic components. These effective bias ingredients permit us to save computational time and memory requirements, to efficiently produce mock galaxy catalogues. These are useful to study systematics of survey, test analysis tools, and compute covariance matrices to perform a robust analysis of the data. Moreover, this description permits us to implement them in inference analysis methods to recover the dark matter field and its peculiar velocity field. I will show some examples based on the largest sample of luminous red galaxies to date based on the final BOSS SDSS-III data release.

The amount of data available in image guided medical interventions and surgeries is growing at a rapid rate. More data per device and more devices present during individual procedures result in a situation, where the interventionalist is often overwhelmed by the amount and complexity of the data available. The lack of integration of the varying source of information is due to the lack of adopted standards and is accentuating this problem. The presentation will cover some of the root causes of this situation and discuss possible solutions.

Using ~320h of good-quality Crab data from Feb 2007 to Apr 2014 the MAGIC telescopes measured the most energetic pulsed photons from a pulsar to date. The new results obtained probe the Crab Pulsar as the most compact TeV accelerator known to date. The remarkable detection of pulsed emission up to 1.5 TeV revealed by MAGIC imposes severe constraints on where and how the underlying electron  population produces  gamma-rays  at  these  energies. Such TeV pulsed photons require a parent population of electrons with a Lorentz factor of at least 5E6. These results strongly suggest IC scattering off low-energy photons as the emission mechanism and a gamma-ray production region in the vicinity of the light cylinder, requiring a revision of the state-of-the-art models proposed to explain how and where gamma-ray pulsed emission from 100 MeV to 1.5 TeV are produced. Investigating the extension of the very high-energy spectral tail of the Crab Pulsar at energies above 400 GeV, the pulse profile was found to show two narrow peaks synchronized with those measured in the GeV energy range. The spectra of the two peaks follow two different power-law functions from 70 GeV up to 1.5 TeV and connect smoothly with the spectra measured above 10 GeV by the Large Area Telescope (LAT) on board the Fermi satellite.

The Square Kilometre Array (SKA) project intends to build a radio-interferometer with 1-sq-km collecting area, and thousands of antennas with baselines up to 3000 km, to be hosted in two continents (Africa and Oceania). This will provide tens of times more sensitivity and allow astronomers to survey the entire sky thousands of times faster than any system currently in existence, with the ability to image huge areas of sky in parallel.

Spain is actively participating in the SKA detailed design phase, both at a scientific and technological level. The potential of SKA for fundamental breakthroughs in Astrophysics, Physics, and Astrobiology has made that the Spanish SKA White Book has been published, with more than 125 authors who have summarized in 29 chapters the interest of the Spanish scientific community. At the same time, SKA constitutes a technology tractor for high-impact societal areas. Among the 100 companies and research institutions across 20 countries that are contributing to SKA design, 10 Spanish research centres and 11 companies participate in several work packages (Dishes, Signal & Data Transport, Central Signal Processor, Science Data Processor, Telescope Manager, and Infrastructure). This Spanish technological participation in the SKA, with an estimated financial value of ~€2M, has been officially acknowledged by the SKA Board. Since October 2013 a representative of the Spanish government has been regularly invited to participate in the SKA Board meetings. Furthermore, at the beginning of 2014, the Board of the Spanish Astronomy Infrastructures Network endorsed the recommendation issued by the Radio Astronomy Infrastructures working group on the interest of the scientific community and industry that Spain explores the possibility to join the SKA project as Full Memb er before the construction phase starts. The interest of the Spanish community and industry was restated during the SKA Spanish day held in October 2014 while a new SKA Spanish Industry Day will be organized by CDTI in 2016.

The aim of this talk is providing a retrospective view of the Spanish participation in SKA project and explain the current status of its participation and opportunities of involvement.

In this talk we will review  the SPICA mission and present its current status under the new framework. Optimized for mid- and far-infrared astronomy with a cryogenically cooled ~2.5m telescope, SPICA will achieve high spatial resolution and unprecedented sensitivity in this wavelength domain. It will enable to address fundamental problems in astrophysics ranging from the formation of planets to the star-formation history of the universe.

Even though astrophysics and medicine seem far away from each other, they share instrumental features such that IAC could become an important stakeholder for state-of-the-art medical technology conception. In fact, as astrophysics, medicine is more than ever based on high-end technology. Since R?tgen discovered the X radiation in 1895, there has been a continuous flow of knowledge and technology transfer from the basic science laboratory to the clinical arena. Remarkably several Nobel prizes have been awarded for research that turned out most useful for medical instrumentation. Besides X-ray, computed tomography and magnetic resonance are prominent examples. Astrophysics deals with electromagnetic radiation. Extremely sensitive sensors detect weak radiation across the electromagnetic spectrum in order to analyze its composition and features, as they provide relevant clues and information about the originating cosmic processes. In medicine electromagnetic radiation is most relevant too, yet it doesn?t come from space but from the body under inspection. Such radiation can be emitted by the body itself, due to its own temperature, or it can be originated at an external source and then absorbed, reflected, transmitted or scattered by the body biological tissues. Different processes can be studied across the electromagnetic spectrum providing not only relevant clues on the underlying biological processes, but important diagnostic and therapeutic information. The seminar will discuss similarities and differences between astrophysical and medical technology, so as to leverage synergies between both fields. To this extent instrumental methods in medicine based on electromagnetism will be reviewed, paying a particular attention to imaging modalities. A main goal will be to identify instrumental modalities mastered in astrophysics but not used customarily used in medicine yet, which boast promising features for clinical applications: microwave and infrared thermography, near infrared and hyper-spectral imaging are among them. A first of such applications will be discussed: microwave and infrared thermography for early detection and monitoring of diabetic foot complications. Diabetes is a global concern, with high morbility and cost. The WHO estimates its prevalence about 9% globally. Prevalence in the Canary Islands is higher, with estimates around 14% of the adult population. Vascular and neuropathic complications are quite common, being diabetic foot most prominent. Undetected complications can lead to serious infections and foot amputation. A low-cost passive system will be discussed for non-invasively detecting temperature abnormalities using microwave and infrared thermography, which correlate with early unnoticed symptoms. Currently available experience at IAC on microwave and far infrared sensor technology could be a major opportunity to design and build a practical prototype of such system, which once clinically tested should be developed and globally marketed by the industry, with royalties returned to IAC.

In collaboration with member states institutes, the use of the synergies with ESO is producing first important results in the R&D for Laser Guide Star adaptive optics, to be used for the large and extremely large telescope projects.

In this talk we will report on the preliminary results of the current campaign on LGS return flux with laser guide stars at Observatorio de el Teide and the foreseen tests of the EELT LGS-AO scheme, to be done at the WHT starting in summer 2016. An outlook will be given on the proposal for further feasibility tests at WHT in 2018-19, to experiment novel LGS-AO schemes using uplink beam correction and pyramid wavefront sensing. The demonstration is for a LGS-AO scheme giving high Strehl on the EELT and adaptive optics in the visible on 8m class telescopes.

Understanding the stellar initial mass function (IMF) is a key aspect to obtain a complete picture of galaxy formation and evolution. In the past years, we have carried out a systematic census of the IMF in the unresolved stellar populations of (massive) early-type galaxies (ETGs), using optical and NIR spectroscopy from different surveys (e.g.  SDSS, CALIFA) and dedicated observing programmes (OSIRIS@GTC, XSHOOTER@VLT).  I will present results on a non-universal IMF in ETGs - pointing to an excess of low-mass stars in high-, relative to low-, mass galaxies - and current constraints on the physical driver behind the IMF variations.

The search for detection of gamma-rays in the very-high-energy range (VHE, >100GeV) from distant AGNs by Imaging Atmospheric Cherenkov Telescopes (IACTs) gets very complicated at high redshifts, not only because of the lower flux due to the distance of the source, but also due to the consequent absorption of gamma-rays by the extragalactic background light (EBL), affecting VHE sources at z~0.1 and beyond. The farthest source ever detected in the VHE domain was the blazar PKS1424+240, at redshift z>0.6. In the last months MAGIC, a system of two 17 m of diameter IACTs located in the Canary island of La Palma, has been able to go beyond that limit and to push the boundaries for VHE detection to redshifts z~1. The two sources detected and analyzed, blazar S30218+35 (Atel discovery #6349) and FSRQ PKS1441+25 (Atel discovery #7416) are located at redshift z=0.944 and z=0.939 respectively. S30218+35 is also the first gravitational lensed blazar ever detected in VHE. The multiwavelength dataset collected allowed us to test for the first time the present generation of EBL models at such distances. I will show results on MAGIC analysis on S30218+35 and PKS1441-25, including spectral energy distributions and EBL absorption studies, in a multi-wavelength context.