A team from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), affiliated to the Institute of Space Studies of Catalonia (IEEC) has taken part in this second release. This group leads the work of the mission file, and has also participated in this work. Moreover, Barcelona is the headquarters of one of the five data centers of the mission, among which are the Barcelona Supercomputing Center (BSC) and Consorci de Serveis Universitaris de Catalunya (Catalan Consortium of University Services, CSUC). The BSC offers the resources to conduct a part of the operations during the mission. At the moment, the BSC has also a safety copy of all the data for the Gaia satellite.

The catalogue has been carried out with data obtained by the satellite over the first twenty-two months of the mission. The file with these data, which are published today, is open to the scientific community, amateur astronomers and the general public. Regarding the first catalogue, published in September 2016, the new data include movements and parallax, which enables having –for the first time- a three-dimensional map of the galaxy, analysing the movement of 1 % of the stars that build it, and studying the structure and movement of the surrounding spiral galaxies.


The most precise universe in motion

This second catalogue has the positions of more than 1,700 million stars, and the parallax –which provides distance-, own movements, and photometry –brightness and colors- of more than 1,300 million stars.

In addition, the catalogue has more than seven million stars with measurements of their radium speed (speed at which the star gets closer or far), 550,000 light curves of variable stars that allow a critical review of the Universe distance scale; astrometry and photometry measurements for 14,000 asteroids, and the temperature of 160 million stars. The Gaia satellite has also observed the position of extragalactic objects such as quasars and faraway galaxies.

The central file of the mission is managed at the European Space Astronomy Centre (ESAC, in Madrid). The obtained map has a precision of 40 microseconds of arc for the brightest stars, and 700 microseconds of art for the weakest ones, therefore being the most accurate sky map.


Gaia’s potential for science

Moreover, researchers from the Gaia consortium publish today six scientific articles in the journal Astronomy & Astrophysics, using these data. These articles show the potential of the new data to work on science. Gaia opens a new window for the studies on stellar physics and formation mechanisms and evolution of stars, from the Galaxy and the surrounding satellite galaxies. These enable researchers study the rotation of the Magellanic Clouds, two small galaxies that are in the Milky Way; as well as galaxies closer to the Andromeda and Triangulum galaxies. The analysis of the motion of stars in the Milky Way will enable researchers to set the distribution of dark matter in our galaxy, an essential piece to progress in the knowledge of its nature. Another application of the map built with data from Gaia is the fact that it will improve observation predictions on astronomical phenomena, such as a star eclipse by one of the small planets or asteroids in the solar system.

Gaia Mission

The Gaia satellite, sent to space in December 2013 by the European Space Agency, aims to create the most accurate map of the Milky Way. With precise measurements of the positions and motions of the stars in the Milky Way, it will answer doubts on the origin and evolution of our home galaxy. The satellite is at 1,5 million kilometres from the Earth. The mission, with a 5-year initial length, was recently extended until 2020. More than a billion astrometry measurements have been carried out so far.
The central file of the mission is carried out at the European Space Astronomy Center (ESAC), in Madrid.


Participation of the University of Barcelona

The team of ICCUB (UB-IEEC), led by Professor Jordi Torra, from the Department of Quantum Physics and Astrophysics, and the tenured university lecturers Xavier Luri, Carme Jordi and Francesca Figueras, have taken part in the Gaia mission since the beginning, with an important role: they contributed to the scientific and technological design of the project and the prototype of the system for the astrometry data treatment, and have led the production of simulated data during the preparation phase of the mission.

Regarding the data to be published now, the team of Barcelona is leading the group that works on the file of the mission. They are also in charge of the initial process for the treatment of data that arrive to the satellite every day, the first step to get scientific results such as the ones to be published now. The group is also in charge of the pairing process for the different observations of a star, and collaborates with the calibration of star brightness and takes part in the scientific data exploitation.

The ICCUB Gaia team (UB-IEEC), formed by twenty scientists and engineers, was awarded in 2013 the Premi Ciutat de Barcelona to Experimental Sciences and Technology. The team is integrated in the Data Processing and Analysis Consortium (DPAC), which gathers more than 400 people from twenty European countries, and leads the creation of the file. Some of its members are part of the Gaia Science Team (GST), ESA’s scientific advisor body.


More information about the Gaia Mission at the ESA website.

ICCUB researchers pay tribute to him in the press:

• Jaume Garriga,:
• "Els matins de Catalunya Ràdio", (From min:8:50)
• L'astre s'ha apagat. "El Periódico", 15/03/2018
• "VersióRac1". 14/03/2018, [From min 20]
• David Mateos:
• La gran aportació de Stephen Hawking: els forats negres també emeten radiació, Telenotícies TV3, 14/03/2018
• J.M. Carrasco:
  • "La República Santboiana"
• V. Bosch:
  • "La sexta, notícias" (From min:40)
• R. Emparan:
• Mor el referent del’astrofísica Stephen Hawking, El Punt Avui. 15/03/2018
  
• No deixis mai de mirar les estrelles, El Periódico. 15/03/2018
• R, Emparan, C. Germani, L. Verde:
• Viatge al Cosmos extrem. El Periódico 15/03/2018

After the signal being simultaneously detected by the two LIGO detectors in USA and VIRGO in Italy, the position of the event could be precisely triangulated and scientists could locate it in a relatively small patch in the southern sky. Fermi Observatory was able to provide a localization that was later confirmed and greatly refined with the coordinates provided by the LIGO-Virgo detection. With these coordinates some 70 ground- and space-based observatories could point their telescopes to the event and perform follow-up observations in all the range of the electromagnetic spectrum.

The observed event was the merging of two neutron stars located at the relatively close distance of about 130 million light-years from Earth. As these neutron stars spiraled together, they emitted gravitational waves that were detectable for about 100 seconds. This is a much longer period than when two black holes collide, providing scientists with more detailed information on gravitational waves. After the collision, a flash of light in the form of gamma rays was emitted and seen on Earth about 2 seconds after the gravitational waves. In the days following the smashup, other forms of or electromagnetic radiation were also detected.

This observation will also represent a remarkable increase in our knowledge on neutron stars, in particular concerning the production of heavy metals such as gold and platinum, as well as on other astrophysical phenomena such as the origin of gamma ray outbursts.

More information: NSF press release

ICCUB related news and activities:

• Interview with R. Emparan on Catalunya Ràdio.
• New details and discoveries made in the ongoing search for gravitational waves Online retransmission of NSF press conference

Download full release:   English   Spanish     ICCUB Contribution to CTA

“The release of this document represents a major milestone for CTA, and it details the breadth and the richness of the science that will be done with the observatory over the next decade,” says CTA Co-Spokesperson Prof. Rene Ong. “The document would not have been possible without the hard work of literally hundreds of CTA Consortium members over a period of many years.”

CTA will seek to address a wide range of questions in astrophysics and fundamental physics that fall under three major study themes: understanding the origin and role of relativistic cosmic particles, probing extreme environments and exploring frontiers in physics (Chapter 1).

“The Key Science Projects described in the document – surveys and deep observations of key objects – will provide legacy data sets of lasting value and will provide important input for the planning of CTA’s user programme,” said CTA Spokesperson Prof. Werner Hofmann.

A simulated sky map that will be obtained during the CTA galactic plane survey.

“For me, the most exciting aspect of CTA is the potential for truly unexpected discoveries,” says CTA Project Scientist, Prof. Jim Hinton. “CTA pushes to shorter timescales, higher energies and more distant objects. Pushing back the frontiers in astronomy always leads to something truly new and exciting, and now we’re all just itching to get started.”

It has been a decade since science planning for CTA started, resulting in a series of publications in a special edition of Astroparticle Physics in 2013. The current work began that same year with an organized effort by the CTA Consortium to develop CTA’s Key Science Projects (KSPs) in 2013. After three years of development and refinement that included internal and external reviews, the KSPs were incorporated into a single document: Science with the Cherenkov Telescope Array.

Cover Image: www.flickr.com/photos/cta_observatory/37070578110/in/album-72157671319679034/

Galactic Plane Image: www.flickr.com/photos/cta_observatory/29047673243/

PDF Press release: Spanish English

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.

MAGIC telescopes and a false-color multiband image of the supernova remnant Cassiopeia A (Cas A) obtained with the three big NASA observatories [(Spitzer (Infrared), HST (optical) and Chandra (X-ray)]. (M. Lopez / IAC / NASA)

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 energetic than the ones we can reach in artificial accelerators such the one in CERN, their energy is not high 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

The 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: https://wwwmagic.mpp.mpg.de/

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 gamma-ray spectrum of the SNR Cassiopeia A". DOI: 10.1093/mnras/stx2079

CONTACTS:

Dr. Razmik Mirzoyan
Max-Planck-Institute for Physics, Foehringer Ring 6
80805 Munich, Germany
Tel.: (+49)(89)-323-54-328
e-mail: Razmik.Mirzoyan@mpp.mpg.de
e-mail: Mirzoyan.Razmik@gmail.com

At ICCUB:

ICCUB Scientific Office
Facultat de Física, C. Martí i Franquès, 1
secretariacientifica@icc.ub.edu
+34 93 402 01 46

Cassini is ending its 13-year tour of the Saturn system with an intentional plunge into the planet to ensure Saturn's moons – in particular Enceladus, with its subsurface ocean and signs of hydrothermal activity – remain pristine for future exploration.

NASA news

Josep Manel Carrasco talks about the end of the Cassini-Huygens mission on the "La República Santboiana" programme on Radio Sant Boi. (20/09/2017)

Link with the programme