News & Press releases

Número de entradas: 95

Septiembre 2017

Prime candidate to explain cosmic ray sea runs short of energy

The MAGIC telescopes have now observed that one of the best candidates of CRs acceleration, Cassiopeia A falls short of energy.
Cassiopeia A is a famous supernova remnant, the product of a gigantic explosion of a massive star about 350 years ago. Although discovered in radio observations 50 years ago, now we know that its emitted radiation spans from radio through high-energy gamma rays. It is also one of the few remnants for which the birth date and the type of supernova are known. It was a type IIb, the result of a core collapse supernova explosion -. The precise knowledge of its nature makes Cassiopeia A one of the most interesting and investigated objects in the sky, and in particular the study of its connection with the cosmic rays, sub-atomics particles that fill our Galaxy with energies higher than anything achievable in laboratories on Earth.
The very high-energy part of the spectrum of Cassiopeia A results from the cosmic rays (either electrons or protons) within the remnant. Until now, this range of energy could not be measured with sufficient precision to pinpoint its origin. Sensitive observations above 1 Tera-electronvolts (TeV) were required but achieving them was daunting. An international team led by scientists from the Institute for Space Sciences (ICE - IEEC-CSIC, Spanish National Research Council-CSIC), the Institut de Fisica d’Altes Energies (IFAE) and the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), in Spain, has finally succeeded in doing those observations with the MAGIC telescopes (short for Major Atmospheric Gamma-ray Imaging Cherenkov Telescope). More than 160 hours of data were recorded between December 2014 and October 2016, revealing that Cassiopeia A is an accelerator of massive particles, mostly hydrogen nuclei (protons). However, even when those particles are 100 times more energetics than the ones we can reach in artificial accelerators such the one in CERN, their energy is not hugh enough to explain the cosmic ray sea that fills our Galaxy.
“Cassiopeia A is the perfect object to be a PeVatron, that is, an accelerator of particles up to PeV energies (1 PeV = 1.000 TeV): it is young, bright, with a shock expanding a great velocity and with very large magnetic fields that can accelerate cosmic rays up to at least, conservatively, 100 or 200 teraelectronvolts” explains Emma de Oña Wilhelmi, scientist of CSIC in the Institute for Space Sciences, “But contrary to what we expected, in Cassiopeia A the particle energies do not reach more than a few tens of tera-electronvolts. At these energies, the radiation suddenly drops and the emission stops abruptly: Either the remnant cannot accelerate the particles to higher energies, which challenge our knowledge of shocks acceleration, or maybe, the fastest ones escaped quickly the shock, leaving only the slowest ones for us to observe”, adds Daniel Guberman, at the Institut de Fisica d’Altes Energies.
“Those supernovae are natural accelerators of particles, therefore the perfect laboratory to study charge particles and plasma in conditions that are not possible in our labs in Earth", remarks Daniel Galindo, working at Institute of Cosmos Sciences of the University of Barcelona (ICCUB). “To understand the origin of the cosmic rays implies to unveil the origin of our own Galaxy”, concludes Razmik Mirzoyan, MAGIC Spokeperson from the Max Planck Institute for Physics (MPP) in Munich (Germany).

MAGIC telescopes

MAGIC telescopes are located at the Roque de los Muchachos Observatory, in La Palma (Canary Islands). MAGIC, a system of two 17m diameter Cherenkov telescopes, is currently one of the three major imaging atmospheric Cherenkov instruments in the world. It is designed to detect photons tens of billions to tens of trillions times more energetic than visible light. MAGIC also uses a novel technique to reduce the effect of the Moonlight in the camera, allowing for observations during moderated Moonlight nights.
MAGIC has been built with the joint efforts of an international collaboration that includes about 160 researchers from Germany, Spain, Italy, Switzerland, Poland, Finland, Bulgaria, Croatia, India, Japan, Armenia and Brazil.

For more information on MAGIC, visit:

Published in the Monthly Notices of the Royal Astronomical Society (MNRAS, 2017): MAGIC Collaboration (M. L. Ahnen et al.) "A cut-off in the TeV gammaray spectrum of the SNR Cassiopeia A". DOI: 10.1093/mnras/stx2079
Septiembre 2017

ESA's INTEGRAL satellite selects a figure in one of our papers as picture of the month

A broad-band study of the 2015 outburst of EXO 1745-248 with INTEGRAL and XMM-Newton is chosen as INTEGRAL's result of the month
From the ESA website:

Low Mass X-ray Binaries (LMXBs), binary systems containing a compact object, are among the brightest and most extreme systems in the Universe. In these systems a neutron star (1.4-2 M⊙) or black hole (5-15 M⊙) accretes matter transferred by a low-mass (less than 1 M⊙) companion star. This matter in-spirals toward the compact object usually forming an accretion disk in which a large amount of potential energy is dissipated reaching temperatures of tens to hundreds of millions of degrees Kelvin and making LMXBs powerful sources in the soft and hard X-ray band. The low magnetic field of the compact objects allows the disk to extend to small radii, experiencing strong gravity and reaching high velocities, thus making these systems ideal laboratories to study the behavior of the accretion flow in the relativistic regime.

With the aid of the ESA missions XMM-Newton and INTEGRAL, a transient neutron star LMXB, EXO 1745-248, hosted in the Globular Cluster Terzan 5, has been studied during an X-ray outburst. The high-quality broad-band spectra provided by INTEGRAL have helped to constrain the continuum, dominated by a high-temperature (40 keV) thermal Comptonization, allowing the high energy resolution, spectroscopic instruments onboard XMM-Newton to unveil a wealth of narrow and broad emission lines superimposed to the continuum.

Features at energies compatible with K-α transitions of ionized Sulfur, Argon, Calcium, and Iron were detected, with a broadness compatible with Doppler broadening in the inner part of an accretion disk truncated at about 40 km from the neutron star center. Strikingly, at least one narrow emission line ascribed to neutral or mildly ionized Iron is needed to model the prominent emission complex detected between 5.5 and 7.5 keV. The different ionization states and broadness suggest an origin in a region located farther from the neutron star than where the other emission lines are produced.

In the figure the light curve of the 2015 outburst displayed by EXO 1745-248 as observed by IBIS/ISGRI and JEM-X on board INTEGRAL is shown. For completeness, the light curve obtained from Swift/XRT (and published previously by Tetarenko, 2016) is also shown. The hard-to-soft spectral state transition of EXO 1745-248 around 57131 MJD is marked with a dashed vertical line in the plots. Around this date, the count-rate of the source in the IBIS/ISGRI decreases significantly, while it continues to increase in JEM-X. The times of the XMM-Newton observation are also marked by red dashed vertical lines. Broad-band spectra of the source during the outburst are also shown together with the best fit model (upper panel), and residuals in units of sigma with respect to the best fit model (bottom panel). The spectra from different instruments have been fitted simultaneously. These are XMM-Newton/RGS1 (red), XMM-Newton/RGS2 (green), XMM-Newton/EPIC-pn (black), INTEGRAL/JEMX1 (blue), INTEGRAL/JEMX2 (cyan), and INTEGRAL/ISGRI (magenta).

This study has been led by the University of Palermo (Italy) and the INAF - Astronomical Observatory of Rome (Italy), has been partially performed at the Institut de Ciéncies de l'Espai (IEEC-CSIC) in Barcelona (Spain), in collaboration with the ISDC - Data Centre for Astrophysics in Versoix (Switzerland), the University of Cagliari (Italy), and other European institutions.

Reference:"XMM-Newton and INTEGRAL view of the hard state of EXO 1745-248 during its 2015 outburst",
M. Matranga, A. Papitto, T. Di Salvo, E. Bozzo, D. F. Torres, R. Iaria, L. Burderi, N. Rea, D. de Martino, C. Sanchez-Fernandez, A. F. Gambino, C. Ferrigno, L. Stella,
2017, A&A, 603, A39
Agosto 2017

El Dark Energy Survey publica la medida más precisa de la estructura de la materia oscura en el universo

El Dark Energy Survey publica la medida más precisa de la estructura de la materia oscura en el universo
El nuevo resultado compite en precisión con las medidas de la radiación de fondo de microondas y confirma que la materia oscura y la energía oscura componen la mayor parte del cosmos.

Investigadores del Centro de Investigaciones Energéticas, MedioAmbientales y Tecnológicas (CIEMAT) , el Institut de Ciències de l'Espai (IEEC-CSIC) , el Institut de Física d'Altes Energies (IFAE) y el Instituto de Física Teórica (UAM-CSIC) participan en el resultado.

Barcelona/Madrid, 3 de agosto de 2017

Imaginad plantar una semilla y ser capaces de predecir con gran precisión la altura exacta del árbol que crecerá a partir de ella. Ahora imaginad poder viajar hacia el futuro y hacer una fotografía que demuestre que vuestra predicción era correcta.

Si tomamos la semilla como el universo primitivo, y el árbol como el universo actual, podemos hacernos una idea de lo que la colaboración Dark Energy Survey (DES) acaba de hacer. En una presentación que tendrá lugar hoy en la reunión de la American Physical Society Division of Particles and Fields en el Fermi National Accelerator Laboratory, cerca de Chicago, investigadores de DES mostrarán la medida más precisa jamás hecha de la estructura a gran escala del universo actual. Los resultados también se presentarán el viernes 4 de agosto por la mañana en el Centro de Ciencias Pedro Pascual de Benasque, donde el director del proyecto DES, el Prof. Joshua Frieman, junto con otros varios investigadores de la colaboración, tanto españoles como extranjeros, y otros científicos, asisten a una reunión internacional para discutir los últimos resultados en las medidas del cosmos y su interpretación teórica.

Estas medidas de la cantidad y distribución de materia oscura en el cosmos actual se han hecho con una precisión que, por primera vez, rivaliza con la de las medidas del universo primitivo hechas por la misión espacial Planck de la Agencia Espacial Europea (ESA). El nuevo resultado del DES (el árbol, en la metáfora anterior) está cerca de las “predicciones” para el universo actual hechas a partir de las medidas de Planck del pasado lejano (la semilla). Los nuevos resultados permiten a los científicos comprender más sobre las maneras en que el universo ha evolucionado durante más de 14 mil millones de años.

“Por un lado es emocionante poder confirmar las predicciones del modelo estándar y aportar los resultados más precisos sobre el ritmo de crecimiento de estructuras cósmicas”, ha declarado Enrique Gaztañaga, investigador principal en el Institut de Ciències de l'Espai (IEEC-CSIC). ”Pero todavía no hemos encontrado una pista definitiva de por qué el universo se está acelerando.”

Lo más notable es que este resultado apoya la teoría de que el 26 por ciento del universo se compone una forma misteriosa de materia, conocida como materia oscura, y que el espacio está lleno de una energía oscura, también invisible, que está causando la expansión acelerada del universo y que representa el 70 por ciento de su composición. La energía oscura, en su forma más simple, fue planteada como hipótesis por primera vez por Albert Einstein hace un siglo.

Explorando 14 mil millones de años de historia cósmica

Paradójicamente, es más fácil medir la distribución de materia del universo en un pasado lejano de lo que es medirla hoy. En los primeros 400.000 años después del Big Bang, el universo estaba lleno de un gas incandescente, cuya luz sobrevive hasta nuestros días. El mapa de Planck de esta radiación cósmica de fondo de microondas nos da una instantánea del universo en ese momento temprano. Desde entonces, por un lado, la gravedad de la materia oscura ha atraído la masa y ha hecho que se formen estructuras en el universo a lo largo del tiempo. Por otro lado, la energía oscura, con su efecto repulsivo, ha estado combatiendo la atracción de la materia. Usando el mapa de Planck como punto de partida, los cosmólogos pueden calcular con precisión cómo se ha desarrollado esta batalla entre materia y energía oscuras a lo largo de más de 14.000 millones de años.

“Con estas fantásticas medidas, DES está empezando a mostrar la enorme capacidad que tiene para producir resultados que supongan un avance importante en nuestra comprensión del universo. Los próximos años nos pueden deparar sorpresas acerca del lado oscuro del universo”, ha dicho Eusebio Sánchez, el investigador responsable del proyecto en el CIEMAT.

Cosmología observacional de alta precisión

El instrumento principal de DES es la Dark Energy Camera que, con 570 megapíxeles, es una de las cámaras astronómicas más potentes existentes en la actualidad, capaz de capturar imágenes digitales de galaxias a ocho mil millones de años luz de la Tierra. La cámara se construyó y probó en Fermilab, el laboratorio principal del Dark Energy Survey, y el grupo español de la colaboración contribuyó decisivamente a su construcción, ya que fue responsable del diseño, fabricación y verificación del sistema electrónico completo, así como del sistema de guiado del Telescopio. Los investigadores de DES usan la cámara durante cinco años para estudiar un octavo del cielo con un detalle sin precedentes. El quinto año de observación comenzará a mediados de agosto.

"Es un placer ver como empiezan a llegar los resultados de un proyecto en el que los grupos españoles nos involucramos desde el principio, hace ya 12 años, y donde hemos hecho contribuciones muy relevantes", ha declarado Ramon Miquel, investigador principal de DES en el IFAE en Barcelona.

Los nuevos resultados publicados hoy se basan únicamente en datos recogidos durante el primer año de observación y cubren una trigésima parte del cielo. Los científicos de DES utilizaron dos métodos para medir la materia oscura. Primero, crearon mapas de posiciones de galaxias, y segundo, midieron con precisión las formas de 26 millones de galaxias

lejanas para cartografiar directamente los patrones de materia oscura a lo largo de miles de millones de años luz, usando una técnica llamada lente gravitacional.

Para realizar estas medidas de alta precisión, el equipo de DES ha desarrollado nuevas técnicas para detectar las diminutas distorsiones que las lentes gravitacionales producen en las imágenes que se obtienen de las galaxias lejanas, un efecto que ni siquiera es visible al ojo humano. Las nuevas técnicas hacen posible un avance revolucionario en la comprensión de estas señales cósmicas. En el proceso, crearon el mapa más grande jamás hecho de la materia oscura en el cosmos (ver imagen). El nuevo mapa de materia oscura es diez veces más grande que el que la propia colaboración DES publicó en 2015, y será finalmente tres veces más grande de lo que es ahora cuando se incluyan todos los datos de cinco años de observación.

Científicos del IFAE han sido líderes de una de las técnicas utilizadas en estas medidas, que correlaciona entre sí las posiciones de las galaxias cercanas con las formas de las galaxias lejanas, contribuyendo a la enorme precisión alcanzada. "Con las medidas que hemos hecho, hemos contribuido a entender mejor la relación que hay entre las galaxias y la materia oscura, que es un elemento crucial para realizar este análisis cosmológico", ha comentado Judit Prat, estudiante de doctorado en el IFAE y primera autora de uno de los artículos que se harán públicos hoy. El IEEC-CSIC ha participado en la creación de mapas de materia oscura, las simulaciones y el estudio de agrupamiento de galaxias. El CIEMAT también ha contribuido a la construcción de los catálogos de galaxias y el estudio del agrupamiento de las mismas. Los tres equipos españoles han tenido un papel clave dentro de la colaboración DES en la determinación de la distancia a las galaxias, que es un elemento esencial para poder interpretar los resultados que ahora se anuncian.

Personas de contacto:


Dr. Ramon Miquel, Director de IFAE y Profesor de Investigación ICREA,


Dr. Enrique Gaztañaga, Profesor de Investigación CSIC,


Dr. Eusebio Sánchez, Investigador Científico CIEMAT,


Dr. Juan García-Bellido, Profesor UAM y miembro IFT,

Información Adicional

Los resultados serán publicados el 3 de agosto en La presentación de los resultados se llevará a cabo a las 5 pm hora de Chicago (00:00 del viernes, hora peninsular española) y se transmitirá en vivo en:

The Dark Energy Survey es una colaboración de más de 400 científicos de 26 instituciones en siete países. Su instrumento principal, la Dark Energy Camera, de 570 megapíxeles, está montada en el telescopio Blanco de 4 metros en el Observatorio Interamericano de Cerro Tololo del National Optical Astronomy Observatory en Chile y sus datos se procesan en el National Center for Supercomputing Applications de Illinois en Urbana-Champaign. España fue el primer grupo internacional en unirse a Estados Unidos para fundar el proyecto DES y participa a través de tres instituciones, dos de ellas en Barcelona (el Institut de Ciències de l'Espai,IEEC-CSIC, y el Institut de Física d'Altes Energies, IFAE) y una en Madrid (el Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, CIEMAT).
Julio 2017

Molecular outflow launched beyond the disk around a young star

For the first time, astronomers has observed a molecular outflow being launched from beyond the disk surrounding a young stellar object.
For the first time, an international team of astronomers, including J.M. Girart from the Institute of Space Science (IEEC-CSIC), has observed a molecular outflow being launched from beyond the disk surrounding a young stellar object. Outflows carry away excess angular momentum and it has been proposed that these disk winds should be launched from a wide region in the protoplanetary disk. The recent observations now show that the outflows are asymmetric and that they are launched beyond the edge of the disk, at the position of the landing site of the in-falling material.

A long-standing problem of star formation is how to get rid of the excess of angular momentum from in-falling material in the molecular cloud where a young star is born. In the classical picture, angular momentum is removed both by a stellar wind close to the newly formed star and by a disk wind from a wide region in the protoplanetary disk around the star. The exact location from where such disk winds are launched, however, is not well known.

An international team of astronomers, led by the Max Planck Institute for Extraterrestrial Physics (MPE), now used the ALMA radio telescope to investigate the young stellar object BHB07-11, a precursor of Solar-type stars. “Our continuum data reveal an unprecedented view of the dust distribution in the YSO,” points out Felipe O. Alves from MPE, the lead author of the paper describing the study. “We achieved an enhanced brightness contrast between the circumstellar disk and the surrounding tenuous material - even showing spiral structures.” 

Even more impressive, however, are the observations of the molecular tracers: They show a bipolar outflow launched at symmetric positions with respect to the disk at quite a large distance from the centre. This is the first time that outflow material is seen ejected not from the disk but beyond its edge.  The large offset of the launching position coincides with the landing site of the infall material from the surrounding parent cloud. At the landing site, models predict that magnetic field lines are strongly pinched due to the dragging of the in-falling gas from the inner envelope. The resulting enhanced magnetic field leads to outflows that are efficiently ejected by a magneto-centrifugal mechanism within a narrow region outside the disk edge.

These results have been published in the Letters of the Astronomy and Astrophysics by F. O. Alves, J. M. Girart, P. Caselli, et al. For more information go the original press release at the Max Institute of Extraterrestrial Physics (Germany)
Junio 2017

The Institute of Space Sciences is leading a recently approved ESF-COST Action on Neutron Stars

PHAROS: a new ESF-COST Action funded for fours years to study Neutron Stars, lead by Nanda Rea of the Institute of Space Sciences
The European Science Fundation has funded for four years "PHAROS", a COST Action aimed at studying Neutron Stars via a multi-disciplinary approach, spanning Astrophysics, Gravitational and Nuclear Physics. This COST Action, lead by Nanda Rea (ICE, IEEC-CSIC), comprised 109 proposers from 30 different countries, with the participation of several ICE members (L. Tolos, C. Manuel, D.F. Torres, E. De-Oña Wilhelmi, C. Sopuerta, M. Hernanz, among others). PHAROS has the ambitious goal of tackling key challenges in the physics involved in neutron stars by facing them via an innovative, problem based approach, that hinges on focused, interdisciplinary working groups. Each group will have all the diversified expertise needed to tackle different open aspects of the physics of neutron stars, and will provide to the different communities several tools and deliverables prepared in a shared language, and of easy access for scientists coming from different physics, ranging, for example, from nuclear physics to radio astronomy. Furthermore, key priority of this action is promoting via training, mobility, equal opportunity and outreach activities, enthusiastic students and young researchers from all over Europe, that will grow and spread the Action’s innovative multi-disciplinary approach. Collaboration is an indispensable feature of high-quality and innovative research, and the deeper we dive into specific exciting and complex fields, the more the need of brainpower and resources from complementary kinds of expertise is of crucial importance. This will build on the multi-disciplinary network that PHAROS will create.
Junio 2017

EUMETSAT ROM SAF CDOP-3 meeting num. 20 of the Project Team at the ICE

June 19th and 20th, the Project Team of EUMETSAT ROM SAF CDOP-3 meet in the ICE
On June 19th and 20th it is held the 20th meeting of the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF) CDOP-3 Project Team at the Institute of Space Sciences.
Junio 2017

Una nube caoticamente magnetizada, ¿es o no un lugar para formar una estrella?

ALMA has revealed a surprisingly weak and wildly disorganized magnetic field very near a newly emerging protostar
Un equipo de astrónomos, incluido Josep Miquel Girart (ICE, IEEC-CSIC) ha descubierto que muy cerca de un embrión estelar el campo magnético que lo rodea es sorprendentemente muy débil y desorganizado. Estos resultados sugieren que el papel que juega el campo magnético interestelar en la formación estelar es más complejo de lo que se pensaba.

Los investigadores han usado el radio telescopio ALMA para cartografiar el campo magnético alrededor del embrión estelar llamado Ser-emb 8, que se encuentra a 1.420 años luz en la región de formación estelar que se encuentra en la constelación de la Serpiente. Estas nuevas observaciones son las más profundas hechas hasta ahora alrededor de un embrión estelar.

Estos resultados se han publicado en la revista especializada The Astrophysical Journal Letters, Volume 842, L9.

Más información se puede encontrar en la página de ALMA (sólo en inglés).
Junio 2017

CTA Prototype Telescope, ASTRI,Achieves First Light

First light of ASTRI, a proposed Small-Sized Telescope design for CTA
During the nights of 25 and 26 May, the camera of the ASTRI telescope prototype (pictured to the left) recorded its first ever Cherenkov light while undergoing testing at the astronomical site of Serra La Nave (Mount Etna) in Sicily managed by INAF-Catania. This comes not long after its optical validation was achieved in November 2016. This accomplishment was the first optical demonstration for astronomical telescopes using the novel Schwarzschild Couder dual-mirror design. The ASTRI telescope is a proposed Small-Sized Telescope design for the Cherenkov Telescope Array (CTA).

Although the camera was not fully configured, the ASTRI team was still able to capture its first Cherenkov light and produce beautiful images of the showers generated by cosmic rays in the Earth’s atmosphere. The camera was specifically designed to fit on the dual mirror ASTRI telescopes for covering a large field of view of 10 x 10 degrees.

Three classes of telescope types are required to cover the full CTA very-high energy range (20 GeV to 300 TeV): Medium-Sized Telescopes (12 m diameter dish) will cover CTA’s core energy range (100 GeV to 10 TeV) while the Large-Sized Telescopes (23 m) and Small-Sized Telescopes (4 m) or SSTs are planned to extend the energy range below 100 GeV and above a few TeV, respectively. The ASTRI telescope is one of three proposed SST designs being prototyped and tested for CTA’s southern hemisphere array. It uses an innovative dual-mirror Schwarzschild-Couder configuration with a 4.3 m diameter primary mirror and a 1.8 m monolithic secondary mirror.
Junio 2017

The review by ICREA Professor S.D. Odintsov is accepted in Physics Reports.

The review by ICREA Professor S.D. Odintsov is accepted in Physics Reports.
The review paper by S.Nojiri, S.D. Odintsov and V. Oikonomou, Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution, arXiv:1705.11098 is accepted for publication in Physics Reports. With Impact Factor over 16, this is one of the leading journals in Physics and Astronomy.
Junio 2017

Scientists of the Euclid Consortium announce the release of the largest simulated galaxy catalogue ever built

Scientists of the Euclid Consortium announce the release of the largest simulated galaxy catalogue ever built
Euclid is a space mission of the European Space Agency ( that will map the geometry of the dark Universe and the cosmic history of structure formation in the Universe by taking images and spectra of thousands of millions of galaxies.

The mission, to be launched in 2020, will provide a wealth of unprecedented high quality data collected with two different instruments: an imager at visible wavelenths (VIS) and an spectro-photometer in the near infrared (NISP) . VIS and NISP are built by the Euclid Consortium (  ), an organisation that brings together international teams of astronomers and physicists in charge of the production of the data and the scientific exploitation of the Euclid mission. The combination of these two powerful instruments will provide a unique window to the early stages of evolution of the universe. In particular, it will shed light on the nature of the mysterious dark-energy that drives the observed accelerated expansion of the universe, and test Einstein's general relativity theory on the largest cosmological scales.

Mining this big and complex cosmological dataset is a formidable challenging task involving ESA and hundreds of scientists of the Euclid Consortium from 14 European countries (Austria, Belgium, Denmark, Finland, France, Germany, Italy, the Netherlands, Norway, Portugal, Romania, Spain, Switzerland and United Kingdom), the United States and Canada. A key ingredient in order to prepare the scientific exploitation of this "golden" dataset is the development of synthetic observations of the real survey: a cosmological simulation that matches the expected volume and complexity of the real data. In a massive coordinated effort, a team of scientists of the Euclid project have worked together over the last year to develop the largest simulated galaxy catalogue ever produced, the so-called "Euclid Flagship" mock galaxy catalogue.

The Euclid Flagship mock galaxy catalogue is based on the record-setting 2 trillion (2 followed by 12 zeros) dark-matter particle simulation performed on the supercomputer Piz Daint, hosted by the Swiss National Supercomputing Center (CSCS). The simulation code was developed by a team of scientists at the University of Zurich, led by Joachim Stadel from the Institute for Computational Science. This unique dataset reproduces with exquisite precision the emergence of the large scale structure of the Universe, with hundred of billions of dark matter halos hosting the galaxies we see in the night sky today.

Using this dark-matter cosmic web from the Flagship simulation, a group of scientists of the Euclid Consortium at Institut de Ciències de L'Espai (ICE, IEEC-CSIC) and Port d’Informació Científica (PIC) in Barcelona, in collaboration with the Cosmological Simulations Working Group, led by Pablo Fosalba (ICE, IEEC-CSIC) and Romain Teyssier (Institute for Computational Science at the University of Zurich), have built a synthetic galaxy catalogue using state-of-the-art scientific pipelines that implement the Halo Occupation Distribution technique, a sophisticated recipe to relate dark and luminous matter in the universe.

The Euclid Flagship mock galaxy catalogue contains more than 2 thousand million galaxies distributed over the 3-dimension cosmological volume that Euclid will survey. Synthetic galaxies in this simulation mimic with great detail the complex properties that real sources display: ranging from their shapes, colours, luminosities, and emission lines in their spectra, to the gravitational lensing distortions that affect the light emitted by distant galaxies as it travels to us, the observers.  A dedicated web portal, CosmoHub ( hosted by PIC, the Euclid Spanish Science Data Center, will distribute the Flagship mock data to the 1000+ members of the Euclid Consortium.

Armed with this new virtual universe, scientists will be able to assess the performance of the Euclid mission as a whole, the so-called Science Performance Verification. The Science Performance Verification exercise uses a full end to end simulation of the Euclid mission developed by ESA and the Euclid Consortium and represents a critical milestone of the project.  Moreover the Euclid Flagship mock will be an essential tool to develop the data processing and the science analysis pipelines developed by the Euclid Science ground Segment and the Science Working Groups and will set the science for the exciting discoveries that await the Euclid mission when the real data shall come.

Image 1: Euclid Flagship mock galaxy catalogue (TIFF: 97 MB)

Caption image 1: Euclid Flagship mock galaxy catalogue

False colour images showing a small portion (0.3%) of the full light-cone simulation of mock galaxies in the Euclid survey.

Light-cone stripes extend 500 Mpc/h (vertical) x 3800 Mpc/h (horizontal axis). The 2-dimension "pencil beam" images result from a slice of the 3-dimension light-cone, projected from a 40 Mpc/h width (in the direction orthogonal to the image plane).

From top to bottom, panels display the full sample of galaxies in the mock, and the sub-samples expected from observations in the VIS and NISP-Halpha channels.

The galaxy mock has been produced using a Halo Occupation Distribution pipeline developed by the Institut de Ciències de l'Espai (ICE) and Port d'Informació Científica (PIC) in Barcelona, and it is based on the 2 trillion dark-matter particle Flagship run produced by U.Zurich.

Image 2: Galaxy types in the Flagship mock (TIFF: 208 MB)

Caption image 2: Galaxy types in the Flagship mock

Top panel: False colour images showing a small portion (0.3%) of the full light-cone simulation (similar to Image 1), but showing different galaxy types with different colours. Central galaxies are coloured in green, and satellites in red.

Bottom panel: zoom in of the top panel image that displays the local universe with greater detail. Central galaxies populate all dark-matter halos of the cosmic web, whereas satellite galaxies tend to reside in the most massive halos, that is, in the highest density peaks of the underlying dark-matter distribution.

Credit: J. Carretero/P. Tallada/S. Serrano for ICE/PIC/U.Zurich and the Euclid Consortium Cosmological Simulations SWG

For further information please contact:

Francisco Castander
Galaxy Mock Production Work Package Lead

Pablo Fosalba
Cosmological Simulations SWG Lead

Yannick Mellier
Euclid Consortium Lead

Joachim Stadel
Large N-Body Simulations Work Package Lead

Romain Teyssier
Cosmological Simulations SWG Lead
Institute of Space Sciences (IEEC-CSIC)

Campus UAB, Carrer de Can Magrans, s/n
08193 Barcelona.
Phone: +34 93 737 9788
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An institute of the Consejo Superior de Investigaciones Científicas

An institute of the Consejo Superior de Investigaciones Científicas
Affiliated with the Institut d'Estudis Espacials de Catalunya

Affiliated with the Institut d'Estudis Espacials de Catalunya