Cosmology and Astroparticles

Astroparticle physics: cosmic-rays and gamma-rays.

The Astroparticle physics group at the IAC is involved in two major collaborations: The Alpha Magnetic Spectrometer (AMS) at the International Space Station (ISS) and the MAGIC Telescopes.

AMS will provide knowledge of the spectrum and chemical composition of the cosmic rays at a level not known before. The IAC aims to use the AMS data to study the cosmic-rays acceleration mechanisms in action in the most extreme astrophysical environments (supernovae remnants, pulsars, black holes, etc.) and to understand the cosmic-ray chemical evolution in our Galaxy produced by spallation processes in the interstellar medium (primary species like C, N and O trasform into light secondary species like Li, Be and B). AMS data combined with complementary observations of very-high energy (VHE) gamma ray photons with the MAGIC telescopes, will provide new key insights on cosmic and gamma ray sources. In collaboration with CIEMAT we also aim to study high redshift cosmic ray nuclei and carry out indirect searches for dark matter using these experiments.

There have been also important activities in promoting the Teide Observatory candidacy to host the CTA-North observatory. These activities are associated with data-taking at the proposed site, as well as to show to the collaboration the benefits for CTA if locating its North observatory in Tenerife.

Cosmology

The Severo Ochoa project is also supporting the major center goals in the Cosmology research line:

1) Exploring the Physics of the Early Universe and primordial gravitational waves. The study of the temperature and polarization anisotropies of the relic Cosmic Microwave Background (CMB) radiation is an essential tool to understand the physical properties of our Universe and its evolution. A unique confirmation of the existence of an inflationary episode in the Early Universe at energy scales of 1016 GeV (12 orders of magnitude larger than those achievable at CERN) can be obtained by its imprint in the polarization of the CMB. The cosmology Group at the IAC is involved in two key projects at the frontier of this field: the ESA´s Planck mission, and the QUIJOTE-CMB Experiment (R. Rebolo is co-I and PI respectively) aimed to set major constraints on the inflationary period of the universe and the generation of primordial gravitational waves.
2) Observational constraints on the nature of the dark energy with massive spectroscopic surveys of the distant Universe. What is the dark energy? Is it Einstein´s cosmological constant, or is it a dynamical phenomenon with a (measurable) degree of evolution? These questions can only be addressed using astrophysical probes. IAC is involved in a series of experiments (Planck satellite, the SDSSIII – BOSS project, the BigBOSS, and the ESA´s Euclid satellite) which will shed light on the detailed dynamics of the accelerated expansion and the equation of state of this intriguing energy.

Specific Goals:

• Unveil the genesis and acceleration mechanisms of cosmic and gamma-rays at the highest energies;
• The physics of the Early Universe and primordial gravitational waves via measurements of the Cosmic Microwave Background;
• The nature of dark energy and its evolution via massive spectroscopic surveys of the distant Universe.

Main Scientific Outputs:

2012

• The first telescope of the IAC led experiment QUIJOTE and its multi-frequency instrument have been commissioned at Teide Observatory, the 2nd telescope and two more instruments have started construction.
• IAC has participated in the mass spectrometer AMS at International Space Station which produced its first scientific discovery: an excess of positrons in the cosmic rays.
• IAC formally offered to host CTA (Cherenkov Telescopes) at Teide Observatory.
• IAC researchers participated in the analysis of the SDSS-III BOSS Survey and in the delivery of the first Planck Cosmological results. Both projects provided strong constraints on the equation of state of dark energy.
• IAC co-leads the Spanish participation in the ESA dark energy mission Euclid.

2013

• AMS is just providing the first results after two years of regular data-taking. The first paper was recently released on Physical Review Letters entitled "First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-350 GeV".
• We have continued our implication in the MAGIC Collaboration, including our participation in the commissioning of the update of the MAGIC-I camera.
• In March 2013, the Planck Collaboration released a first set of maps associated to its nominal survey, together with the associated scientific papers. As Core Team members, some researchers from the IAC have participated actively in preparation of these results (Plank Collaboration results 2013 XVI, accepted for publication in Astronomy & Astrophysics). Moreover, The IAC is coordinating the Working Group on galaxy clusters and secondary anisotropies within the Planck consortium. During 2013, the collaboration has produced several papers on this topic (Planck Collaboration XX, XXI and XXIX, 2013 (Astronomy & Astrophysics, submitted); Astronomy & Astrophysics vol. 561, A97). In particular, the IAC group lead by J.A.Rubiño (SO advanced fellow) is taking a key role in the optical follow-up of the counterparts of the newly discovered Sunyaev-Zeldovich cluster candidates, using an ITP programme (ITP13_8) which started the observations last August 2013.
• The project QUIJOTE started observations, the first release of papers is expected during 2014.
• Morfology and galaxy content of superclusters were studied in the context of SDSS. The results were published in Astronomy & Astrophysics.