Recent Talks

Majority of galaxies reside in groups and clusters where they are understood to evolve also through galaxy-galaxy interactions. Multiple mergers at the core of galaxy groups can develop a luminosity deficiency or gap, which is quantified as the difference between the luminosity of the two brightest galaxies in groups and clusters. This observable carries important information about the evolution of galaxy groups, for instance, there are indications that collapsed groups with a large luminosity gap, known as fossil groups, are associated with the halos that are relatively old. In a series of recent studies, employing X-ray, optical and radio observations complemented by cosmological simulations, we have utilised the luminosity gap to probe the formation scenarios for galaxies and specially the most luminous galaxies in groups and clusters, introduce a powerful age-date routine for galaxy groups, and also obtain clues about the AGN activities and the IGM heating.

The chromosphere is the interface between the photospheric solar surface and the outer corona and wind.  In this complex domain the
solar gas becomes transparent throughout the ultraviolet and in the strongest spectral lines while magnetic pressure becomes dominant over gas pressure even in weak-field regions.  Fine-scale magnetically caused or guided dynamic processes in the chromosphere constitute the roots of mass and energy loading of the corona and solar wind. Notwithstanding this pivotal role the chromosphere remained ill-understood after its basic NLTE radiation physics was formulated in the 1960s and 70s.  Presently, both chromospheric observation and
chromospheric simulation mature towards the required sophistication.  The open-field features seem of greater interest than the easier-to-see closed-field features. For the latter, the grail of coronal topology and eruption prediction comes in sight.

I will start with an introductory overview, show movies to present the state of art in observation and simulation, and treat some
recent success stories in more detail.

The IAC is the only Spanish Institution participating as a full member in SDSS-III (2009-2014). The survey finishes in June 2014, and will publicly release all data by the end of the year, including H-band high-resolution spectra for 100,000 stars in the Milky Way and optical mid-resolution spectra for 1.5 million LRGs and 160,000 quasars.

SDSS-IV will immediately follow, including spectroscopic surveys of variable sources, x-ray source follow-up observations, galaxy and quasar redshifts, Integral-field-unit spectroscopy of galaxies and high-resolution infrared spectroscopy of galactic stars, organized in the following projects: Time-Domain Spectroscopic Survey (TDSS), SPectroscopic IDentification of ERosita Sources (SPIDERS), Extended Baryon Oscillation Spectroscopic Survey (eBOSS), Mapping Nearby Galaxies at APO (MaNGA), and the APO Galaxy Evolution Experiment 2 (APOGEE-2).

The participation of the IAC in SDSS is gaining strength. As an example, in the first half of 2013, about 13% of the papers published by IAC researchers used SDSS data, and these papers contributed 33% of the citations received by the IAC in the same period. We will provide an overview of SDSS activities at the IAC, and current plans for participating in SDSS-IV (2014-2020).

1) López-Corredoira & Gutiérrez (2012, RAA, 12, 249): Extremely luminous QSOs exist at high redshift but they are absent at low redshift. Our analyses show that it is not due to any significant evolution of black hole masses or Eddington ratios for equal luminosity QSOs, so the problem can be translated into a "Why are not there QSOs with very high black hole masses at low redshift?". 2) López-Corredoira & Perucho (2012, A&A, 544, 56): The MOJAVE survey contains 101 quasars with a total of 354 observed radio components that are different from the radio cores, among which 95% move with apparent projected superluminal velocities with respect to the core, and 45% have projected velocities larger than 10c (with a maximum velocity 60c). Relativistic Doppler boosting explains these apparent anomalies, but it requires a huge average kinetic power to produce such powerful ejections: ~7×10^{47} erg/s, a significant portion of the Eddington luminosity and on the order of the bolometric luminosity. This amount is much higher than previous estimates of kinetic power on kpc-scales. 3) There are many other pending problems in QSOs in the literature (review at López-Corredoira 2011, IJAA, 1, 73): the different structure of the clouds along the QSO's line of sight and their tangential directions; the spatial correlation between QSOs and galaxies; inconsistencies in the AGN unification model; etc.

The accelerated expansion of the Universe discovered in the late 90's has opened one of the most intriguing questions of modern  physics. To help to understand its origin, and measure the expansion history of the Universe, large galaxy spectroscopic surveys are being carried out and planned for the future. In this talk, I will review the Baryon Oscillation Spectroscopic Survey (BOSS) and the requirements to achieve its precise results. I will then describe a sample of large-volume high-resolution N-body simulations available at MultiDark database,
that are useful to test the models. Finally, I will present some work I have been doing aimed at producing a large number of mock galaxy catalogs using an improved lagrangian perturbation theory calibrated with these simulations. Mock galaxy catalogs are essential to produce reliable cosmological constraints from these surveys.

Next generation of CMB experiments will require a large number of detectors (few tens of thousands) in order to tackle the challenging detection of primordial polarization B modes. Furthermore, high resolution experiments are needed for a detailed study of high redshift objects including clusters of galaxies, proto-clusters and dusty galaxies. Within this context Kinetic Inductance Detectors (KIDs) are a serious alternative to bolometers at millimetre wavelengths. Indeed, KIDs are naturally multiplexed and compact allowing us to construct arrays of thousands of detectors. Furthermore, KIDs present short time constants (below 1 ms) and have been demonstrated to be background limited on ground based observations. The NIKA camera, made of two matrices (200 KIDs each) operated at 140 and 240 GHz, has been installed successfully at the IRAM 30 m telescope in Pico Veleta, Granada. NIKA has provided the first ever scientific quality astrophysical observations with KIDs. In particular RXJ1347.5-1145, a massive intermediate redshift galaxy cluster at z = 0.4516 undergoing a merging event, has been successfully mapped at 12 arcsec resolution by NIKA. NIKA is a general purpose camera and it can be also used for other astrophysical objectives including for example observations of high redshift galaxies and proto-clusters, and detailed intensity and polarisation mapping of star-forming regions in the Galaxy. NIKA is a prototype of the NIKA2 camera that should be installed in 2015 at the IRAM 30 m telescope. NIKA2 should have 2 frequency bands at 150 and 250 GHz with about 5000 detectors in total and polarisation capabilities. NIKA2 will be well-suited for in-depth studies of the Intra Cluster Medium in intermediate to high redshift clusters and the follow-up of clusters and proto-clusters newly discovered by the Planck satellite. Finally, we discuss the possibility of including KIDs in the next generation of CMB satellites as for example PRISM.

About half the baryons in the local Universe could be in the form of a Warm Hot Intergalactic Medium (WHIM). If a large fraction of the gas is ionized, it could produce significant temperature anisotropies in the Cosmic Microwave Background (CMB), generated by the thermal and also the kinematic Sunyaev-Zeldovich effect. We have developed a theoretical framework to describe the mildly non-linear regime of the WHIM that allows us to compute its contribution to CMB anisotropies. We discuss prospective ways of detecting the WHIM contribution using our formalism and discuss our results on PLANCK data and the constraints we set on the WHIM parameters.

In this talk I present an overview of the structure, activity and goals
of the Gaia-ESO survey, a large public spectroscopic survey aimed at investigating
the origin and formation history of our Galaxy by collecting high quality spectroscopy
of representative samples (about 105 Milky Way stars) of all Galactic stellar populations,
in the field and in clusters. Briefly, I discuss the most relevant results obtained so far.
In particular, I present our study on the internal kinematics of Galactic globular clusters based on the radial estimates obtained from the survey complemented with ESO archive data.

Can weather models be helpful for astronomers? In this talk, I do a revision of the state-of-the-art in numerical weather prediction models and its specific applications for astronomical observatories. In the context of flexible scheduling, the weather prediction models, and the mesoscale models in particular, can give a significant contribution in the management of the observing nights based on the forecasted atmospheric conditions. A prototype for the operational forecasting of the Precipitable Water Vapour above ORM for observations in the Infrared, currently under development, is presented and discussed.

Our group is presently conducting an observational campaign, using the 10-meter Gran Telescopio Canarias (GTC), to obtain the transmission spectrum of several exoplanets during a transit event. The GTC instrument OSIRIS is used in its long-slit spectroscopic mode, covering the spectral range of 520-1040 nm, and observations are taken using a set of custom-built slits of various, broad, widths. We integrate the stellar flux of both stars in different wavelength regions producing several light curves and fit transit models in order to obtain the star-to-planet radius ratio Rp/Rs across wavelength. A Markov Chain Monte Carlo (MCMC) Bayesian approach is used for the transit fitting. With our instrumental setup, OSIRIS has been able to reach precisions down to 250 ppm (WASP-48b, V=11.06 mag) for each color light curve 10 nm wide, in a single transit. Central transit timing accuracies have been measured down to 6 seconds.

Here, we will present refined planet parameters, the detection of planet color signatures, and the transmission spectrum of a set of know transiting exoplanets, namely: WASP-43b, HAT-P-32b, HAT-P-12b, WASP-48b. We will also discuss the capabilities and limitations of GTC with current and future instrumentation, and the role of GTC as tool for the follow up of faint Kepler targets. In particular, we will present the GTC observations of the intriguing evaporating planet KIC 12557548b, for which we performed simultaneous color light curves, and a search for alkali elements in its planetary tail. Other setups for observations (Broad and tunable filter photometry) have also been used and will be briefly discussed. The lessons learned from our GTC exoplanet observations will be discussed in the context of the E-ELT future capabilities.