Extragalactic Astrophysics and
Cosmology Department

Artist's conception of the disruption of a star by a supermassive black hole. / Sophia Dagnello

Large scale structure, Supernovae, Galaxy formation and evolution, Massive black holes & Gravity

The Department of Extragalactic Astrophysics and Cosmology investigates the fundamental laws and origins of the universe, using observational data and models to answer foundational cosmological questions. Our research spans early-universe evolution, modified gravity, galaxy formation, and large-scale cosmic structure. We study supernovae as both probes for stellar death and tools for measuring cosmic distances and expansion, and massive black holes, exploring their roles in shaping galaxies and their environments. By combining theoretical and observational approaches, we aim to clarify the complex mechanisms governing the universe’s structure, blending simulations with experimental data for a comprehensive understanding of cosmic evolution.

Main research lines

Analysis tools for large-scale galaxy surveys

Understanding cosmic acceleration and galaxy evolution through the study of the large-scale structure in Cosmic Maps: This includes the development of accurate predictions and models, data-oriented science pipelines and large CMB, weak gravitational lensing and galaxy simulations.

Modified gravities

Modified gravities to understand in a unified way the evolution of our universe: from inflation up to a dark energy/possible future singularity. Vacuum energy fluctuations and the Casimir effect in gravity and cosmology. Black holes and neutron stars in modified gravity and its comparison with observations at strong gravity limit.

AGN and Galaxy Evolution

Understanding how galaxies form and evolve and how this is related to the supermassive black hole located at their center. This includes the study of a wide range of astronomical objects (active galactic nuclei, intermediate-mass black holes, dwarf galaxies, ultraluminous X-ray sources, radio jets, galaxy mergers) following a multiwavelength approach (radio, optical, infrared and X-ray observations) and contrasting observations and machine learning approaches with theoretical models.

The Low Surface Brightness Universe

The low surface brightness universe is considered the final frontier of optical astronomy: objects with the lowest stellar densities, hidden from sky surveys and about which we know very little from more dedicated observations. From the formation and evolution of galaxies and galaxy clusters to the nature of dark matter, the possibilities offered by the study of this field will change the way we see and understand our universe.

Supernovae and stellar transients

Study the physics driving the explosion mechanism of supernovae and other stellar transients, and also focus on improving the understanding of supernovae as cosmological distance indicators.

MICE Simulations

This group is actively involved in developing astronomical surveys and galaxy catalogues, using the Marenostrum supercomputer, one the most powerful supercomputers in Europe. Our aim is to reproduce, with unprecedented detail, the history of the universe, from much before the first stars formed up to nowadays, and determine how well future astronomical surveys, in which we are involved, can answer these fundamental questions.

The Black Hole Universe

In very recent research, it has been found that the inside of a BH could be dominated by a False Vacuum which is trapped together with matter and radiation that are expanding (or contracting) in a state very similar to that in the expanding Universe that we observe around us. We call this solution a Black Hole Universe (BHU). So there could be galaxies, stars, planets and other Black Holes inside any given Black Hole if it is large enough to hold them (i.e. if the mass is large enough).

Experimental Research & Development

DES: The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will reveal the nature of the mysterious dark energy that is accelerating the expansion of our Universe. ICE-CSIC contributed to the development of the DES camera and on the star guider software. ICE-CSIC is responsible for the production of the N-body dark matter simulations (MICE) used in the DES Data Challenges and science analysis.
DESI: The Dark Energy Spectroscopic Instrument (DESI) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions (RSD) with a wide-area galaxy and quasar redshift survey. This powerful instrument will be installed at prime focus on the 4-m Mayall telescope in Kitt Peak, Arizona, along with a new optical corrector, which will provide a three- degree diameter field of view. The DESI collaboration will also deliver a spectroscopic pipeline and data management system to reduce and archive all data for eventual public use. The DESI instrument will be used to conduct a five-year survey designed to cover 14,000 deg2. In total, more than 30 million galaxy and quasar redshifts will be obtained to measure the BAO feature and determine the matter power spectrum, including redshift space distortions. The ICE-CSIC participates in the DESI project as part of the BCN-MAD Regional Participation Group (RPG), composed of ICE-CSIC, IFAE, CIEMAT and IFT. We represent our RGP in the DESI Institutional Board. Our RPG is responsible for delivering the Guiding, Focus and Alignment units of DESI's focal plane. We are also responsible for delivering the guiding software for the instrument. We lead the Image Validation Working Group and participate in other Working Groups.
LSST: The Vera Rubin Observatory’s Legacy Survey of Space and Time (LSST) is a ten-year astronomical survey that will image the southern sky using a dedicated 8.4-meter telescope equipped with the world’s largest digital camera. By observing billions of stars, galaxies, and other celestial objects, LSST will enable unprecedented studies across various fields of astronomy, from the detection of near-Earth objects and transient events, like supernovae, to the investigation of dark matter and dark energy. ICE is part of the BCN-MAD in-kind contribution to Rubin Observatory, which grants LSST data rights.
LS4: The La Silla Schmidt Southern Survey (LS4) is a new time-domain survey to monitor the night sky searching for stellar explosions, stellar variables, and other transients that change brightness on timescales of minutes to years. LS4 uses an upgraded Quest camera providing a total field of view of 20 sq. deg, each quarter observing with a fixed giiz filter. ICE as an institutional member has participated in the proposal of the project and observing strategy, and has a seat in the Collaboration Council.
PAU: The PAU Survey is an international collaboration between Spain, the Netherlands, Switzerland, Germany and the UK to collect a fluxed limited accurate redshift and spectral energy distribution information for millions of galaxies (and stars) to a depth and area never explored before. This is done without the need of target selection which provides a valuable tool to understand sample selection and completeness. ICE-CSIC led the joint effort of a Consortium of Spanish institutions to design and build the PAUCam. ICE-CSIC is also leading the PAU Survey Collaboration and the data reduction, community pipeline, automated analysis pipelines and the data distribution in collaboration with PIC. ICE-CSIC is also leading the scientific exploitation of the PAUS data, including simulations, photometric redshift and clustering forecast and analysis.
Euclid: ESA's Euclid mission is designed to explore the composition and evolution of the dark Universe. It will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and the nature of dark energy and dark matter. ICE’s main contribution, the Euclid Flagship simulation, is a simulated catalogue of billions of galaxies based on the largest cosmological simulation ever conducted, designed to prepare the scientific exploitation for the Euclid mission.
Roman: The Nancy Grace Roman Space Telescope is a next-generation space observatory developed by NASA, designed to investigate fundamental questions in astrophysics and cosmology. Equipped with a 2.4-meter primary mirror and advanced imaging and slit-less spectroscopy capabilities, Roman will have an exceptionally wide field of view, roughly 100 times larger than the Hubble Space Telescope, enabling large-scale surveys of the universe. Key mission goals include probing the nature of dark energy and dark matter by studying the expansion history of the universe, mapping galaxy distributions, and observing distant supernovae. Scheduled for launch in the mid-2027, the Roman Telescope is set to transform our understanding of the cosmos. ICE is participating in the Project Infrastructure Team to Support Cosmological Measurements with Type Ia Supernovae.
ARRAKIHS: Analysis of Resolved Remnants of Accreted Galaxies as a Key Instrument for Halo Surveys is an ESA planned mission. It is an F-class (fast) mission selected in 2022 for launch in the early 2030s. Its goal is to study the low surface Universe (low-mass galaxies, stellar streams and galactic halos) in order to constrain the nature of dark matter. ICE is heavily involved in the mission, both scientifically and instrumentally.
SKAO: The Square Kilometre Array Observatory (SKAO) is a next-generation radio astronomy-driven Big Data facility that will revolutionise our understanding of the Universe and the laws of fundamental physics. SKAO will explore the unknown frontiers of science and deepen our understanding of key processes, including the formation and evolution of galaxies, fundamental physics in extreme environments and the origins of life. ICE-CSIC is involved in several scientific working groups, such as the SKA Continuum, SKA-VLBI, SKA-Cradle of life, SKA-Our Galaxy, SKA-Cosmic Magnetis, SKA-Pulsar or SKA-Transients, and is actively contributing to writing multiple chapters of the SKAO Science Book.