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 for gamma radiation.

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 transform 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 the MAGIC 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 Canarian Observatories candidacy to host the CTA-North observatory. In 2016 Spain and Japan agreed on the installation of four new Cherenkov telescopes, which may form part of the future CTA-North, at the Roque de los Muchachos Observatory, on the island of La Palma.

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 10^16 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 eBOSS, 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:

Cosmic microwave background (CMB) and Planck:

• New measurements of the angular power spectrum of the CMB anisotropies set constraints on main cosmological parameters reaching a precision better than 1% (Planck Collaboration 2016, A&A 594, A13).
• Implications for cosmic inflation of the Planck measurements of the cosmic microwave background (CMB) anisotropies based on the full Planck survey (Planck Collaboration 2016, A&A 594, A20).

Anomalous microwave emission in our Galaxy:

• Best upper limit to date on the polarisation fraction of this emission (Génova-Santos et al. 2017; Poidevin et al. 2019).

Cosmology with galaxy clusters:

• Developed two full-sky catalogues of Sunyaev-Zeldovich sources (PSZ1 and PSZ2).
• Optical follow-up of newly discovered Planck clusters (Planck Collaboration XXXVI 2016; Barrena et al. 2018, A&A; Aguado-Barahona et al. 2019, A&A). 
• Constraints on the sum of the neutrino masses (Planck Collaboration XXIV, A&A, 2016).

Large scale optical and infrared surveys:

• The analysis of BOSS data (Alam et al. 2017; Chuang et al. 2017) set an upper limit of 0.12 eV to the sum of the neutrino masses in combination with Planck data (Pellejero-Ibañez et al. 2017).
• Discovery of a massive supercluster system, the BOSS Great Wall, at z= 0.47 (Lietzen et al. 2016).
• Constraints on the dynamical nature of dark energy (Zhao et al. 2017).
• Accurate halo-galaxy mocks from automatic bias estimation and particle mesh gravity solvers (Vakili, Kitaura et al. 2017).
• Production of detailed simulations of the large-scale structure for DESI and EUCLID (Chuang et al 2019).

Origin of cosmic rays:

• First evidence that blazars are a possible source of cosmic rays protons is reported in the paper "Multi-messenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A", Science 361 (2018) 6398.
• Precision Measurement of Boron-to-Carbon ratio in Cosmic Rays with AMS (AMS Collaboration 2016, Phys.Rev.Lett. 117, 23)

Gamma-ray sources and gravitational waves:

• First TeV emission detected from a GRB (2019 Nature 575 455, Nature 575 459).
• First observation of an electromagnetic counterpart of a Gravitational Wave source (2017 Nature 551, 71).
• MAGIC observes a gravitational lens at very high energies (MAGIC Collaboration 2016, A&A).
• Teraelectronvolt pulsed emission from the Crab Pulsar detected by MAGIC (MAGIC Collaboration 2016 A&A).

Scientific Outputs 2012 - 2015