Instituto de Astronomía Teórica y Experimental

The Seyfert's Sextet

The 13.8 billion years of the Universe is enough time to form giant objects, being the galaxies one of the most interesting. Galaxies are truly island universes where dark matter, billions of stars and huge amounts of gas and dust coexist in equilibrium, and yet, they are an environment suitable for the formation of new stars. Galaxies also tend to cluster in a network of cosmic proportions which highlights fabulous large structures formed by thousands of galaxies. At the IATE, the study of galaxies has been a constant challenge, which has allowed to consolidate over the years different methods for the study of the formation and evolution of galaxies. Some of the most important are:

• Numerical Simulations: the physical processes that govern the evolutionary history of one or many galaxies are recreated by using supercomputers:
• Statistical Studies: properties of galaxies are inferred and analysed from large data surveys;
• Astronomical Observations: classic observations and the most modern and sophisticated techniques are combined by using the telescope facilities around the world.

These and other tools are used by different scientists at the IATE to perform original and reliable astronomical research.

Numerical simulation of a CDM universe with dark energy (Andrey Kravtsov and Anatoly Klypin)

The large-scale structure of the Universe is the field of cosmology that studies the distribution of the matter in the Universe on the largest scales. This field has grown remarkably since the '80s, with the development of three-dimensional maps of galaxies in several bands of the electromagnetic spectrum, and with the observation of the Cosmic Microwave Background (CMB). The increasing flow of information generated by observations has allowed to obtain reliable characterization of the content of the universe comprising

• 74% of vacuum or dark energy,
• 26% dark matter and
• 4% ordinary baryonic matter,

as well as its distribution. The distribution of the structures seems to follow a hierarchical model where the upper level is dominated by a network of clusters and filaments. On top of that, the universe appears to be isotropic and homogeneous in accordance with the cosmological principle. From the analysis of catalogs and the development of numerical simulations, the distribution is characterized through the implementation of different statistics that allow the study of the spatial distribution as well as the dynamics by means of the velocity field of the matter distribution.

Artist's concept of a protoplanetary disk.

The question of the existence of other worlds has been present in the history of mankind for centuries, but only recent scientific evidence has confirmed that planets could exist and are common outside the Solar System. Since the first discovery in 1992, over 850 new exoplanets have been cataloged. Contrary to the Solar System, exoplanets' population presents several examples of exoplanets at very small distances from its stars, highly eccentric planetary orbits, and they are frequently found in configurations not previously imagined. This led to the development of new theories and areas of research, which ultimately can help us to better understand the Solar System. Some of the projects that are currently being developed at the IATE include:

• Analyses of observational data for exoplanets (radial velocity and transit);
• Models of tidal interaction with the central star to study the origin of the population of "hot" exoplanets
• Study of the dynamics of extrasolar planets in mean motions resonances;
• Development of hydrodynamic codes to describe the interaction between planets and the protoplanetary disk;
• Analyses of the formation of planets in binary stellar systems.

An eruptive prominence on the surface of the sun.

The plasma is the most common state of the baryonic matter in the Universe (99%). Most of a star, the interplanetary and interstellar medium, and the ionosphere, are plasmas. The plasma can also be generated in terrestrial laboratories for industrial applications such as producing surface coatings, precision cuts in lamps, micro-motors, and plasma reactors. A plasma is a fluid consisting of a large number of free charged particles (globally neutral and whose kinetic energy is larger than the electrostatic potential energy between them). The charges and currents that conform a plasma are sources of the electromagnetic fields and, in turn, these fields affect the distribution of charges and currents which makes its dynamics highly nonlinear and very different from that of a neutral gas. When the magnetic fields are capable of modifying an individual particle trajectory, it is said that the plasma is magnetized. The corona is highly magnetized and therefore, several structures are observed, some of which can maintain its stability for relatively long times as dark filaments on the surface of the sun. In the group of astrophysical plasmas, our scientist perform studies about the dynamic configuration and structures of the corona through the analysis of magnetic arcs and prominences, the formation of voids that remain in the plasma due to the interaction of nonlinear waves, the formation of very energetic shock wave capable of sweeping the chromosphere along a whole quadrant, etc. The team also analyse the interaction of stellar winds with the magnetosphere of exoplanets, and they model the morphology of supernova remnants affected by instabilities and the influence of the magnetic field.

The IATE also performs site testing for the installation of large astronomical facilities in the Argentinian territory. During the 90's (1989-1998), the IATE began the first work on astronomical site testing performing seeing measurements in the Antarctic Base Belgrano II. In 1998, measurements of seeing were performed in the Llano de Chajnantor, Atacama (Chile), as part of a project aimed at installing a liquid mercury telescope in Toco volcano. This project was not successful but the group learnt the use of the most modern technologies for measuring sky parameters. Through this experience, the IATE made contact with Dr. Marc Sarazin, of the European Southern Observatory (ESO), with whom, since the year 2000, the IATE began the searching and characterization of candidate sites to install the European Extremely Large Telescope (E-ELT),[3][4][5][6][7] which will be finally installed in Chile, at the Cerro Armazones. During that work, a suitable candidate site was preselected at the Cordón Macón, close to Tolar Grande town. Because of its excellent conditions, the IATE decided to install observational facilities at this site,[8][9] which is the most important project to date for the instrumentation team. The project also involves the development of a program committed to the educational public outreach in astronomy at the town of Tolar Grande, named Ñawi Puna.[10]

View from the Macón peak at the Cordón Macón, Salta, Argentina.

The first observatory building at the Macón peak (May, 2012).

The IATE is building an astronomical complex on the Cordón Macón, located at 10 km from the town of Tolar Grande, Salta, Argentina. The site is located at latitude 24.61 South and longitude 67.32 West and at an altitude of 4,650 meters. The location has ideal conditions of humidity and air turbulence, which create almost perfect astronomical seeing. The site infrastructure will enable the development of several observational projects:

• The ABRAS project: The Argentina-Brasil Astronomical Center is a project involving both Latin-American countries. The main institutions behind the project are the IATE, from Argentina, and the IAG (Instituto de Astronomia, Geofísica e Ciencias Atmosféricas), from Sao Paulo, Brasil, while the funding institutions are the Ministerio de Ciencia, Tecnología e Innovación Productiva and the University of Sao Paulo (Universidade de Sao Paulo, USP). The project involves the installation of an astronomical observational facility in the Cordón Macón. The 1 meter telescope will be installed in an 8-meter diameter dome. The building and the installation of the dome was performed during 2011-2012, while the 1 meter telescope arrived to Córdoba (Argentina) during October 2015. One of the main goals of the project is to optimize the telescope for performing astronomical observations in the infrared part of the electromagnetic spectrum. The first observations with this telescope is expected to be perform for the year 2016.
• The TOROS project: The Transient Optical Robotic Observatory of the South (TOROS) project is a collaboration among scientists from The University of Texas at Brownsville, the Universidad Nacional de Cordoba (UNC), CALTECH and Texas A&M University. The project intend to construct a dedicated optical follow-up instrument for Advanced LIGO (aLIGO) and Advanced Virgo (AdVirgo) in order to surveying the sky for even very dim afterglows of gravitational waves events. The project also pursuit the aim of detecting nearby supernovas. The first workshop of the TOROS collaboration was held in the city of Salta, Argentina, in June, 2013.
• The ISON project: The International Scientific Optical Network (ISON) program is an international effort that intend to understand and catalogue the space debris population in the near-Earth space and of potentially hazardous Near Earth Objects (NEOs). In order to contribute to this program, the Keldysh Institute of Applied Mathematics (KIAM) of the Russian Academy of Sciences (RAS), of the Russian Federation, will work together with the Comisión Nacional de Actividades Espaciales (CONAE), the IATE, the Observatorio Astronómico de Córdoba (OAC) and the Goberment of the Provincia de Salta in Argentina, to install and operate two small telescopes of 20 and 25 cm of diameter, that will be operated remotely via Internet connection. The aim of this cooperation is to perform observations of orbital debris, asteroids, comets and optical counterparts of gamma-ray bursts.