The first images and catalogues of this international project are fully accessible through its website (https://archive.cefca.es/catalogues/jpas-edr/).

The area of the sky that is open to the public contains 550 000 astronomical objects and is only a small sample of the mapping data, which will observe thousands of square degrees over 10 years. ‘Any future study of these objects can benefit from the information provided by J-PAS. As a legacy project, we believe that J-PAS will become one of the major international references in astrophysics over the next decade. And this release is the first step on this path,’ says Dr Carlos López San Juan, deputy scientific director of CEFCA.

Unprecedented survey

The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) survey is the result of a unique combination: observing a large volume of the Universe in an unprecedented number of photometric bands. The JPCam panoramic camera integrates 56 internationally unique narrow-band optical filters, specially defined for the project. In practice, this means having homogeneous spectral information of all observed objects, which allows deriving astrophysical magnitudes such as the temperature and chemical composition of stars or the age and distance of galaxies, among many others.

J-PAS is set to become the most complete photometric survey of the Universe, as well as an international reference for a multitude of scientific applications. For example, there are already collaborations with other centres to detect galaxy clusters, quasars (there is approximately one for every thousand stars) or low-metallicity stars (very old stars). These first collaborations show that there are as many possibilities as there are data. ‘We don't really know what will be the most relevant discovery that J-PAS will provide. The main objective is cosmological, to understand the nature of dark energy, but the applications in other areas of astrophysics are very numerous and their impact is still unpredictable,’ says Carlos López.

Millions of images of the Universe on a map

J-PAS releases 12 square degrees of sky observed with its 56 filters, corresponding to some 25 000 images recorded in the last year. When completed, in ten years, thousands of square degrees of the sky with hundreds of millions of galaxies and stars will have been observed. The J-PAS images are unique in that they provide information in every pixel of the observed sky. The images themselves are calibrated, which means that the light intensity can be measured at any point in the survey, in its 56 filters.

To carry out the project, hundreds of images are taken every night from the Observatorio Astrofísico de Javalambre (OAJ), which requires a specific data centre for their storage, management and calibration. Transforming the raw data into useful and reliable magnitudes with an unprecedented level of accuracy is an extremely complex process.

The development of image processing tools is another milestone of the J-PAS project. ‘We have developed solutions that can be useful for other survey projects and that will be incorporated into the development of the ARRAKIHS space mission, where our team is in charge of the image processing and analysis software,’ says Dr Héctor Vázquez Ramió, head of CEFCA's Data Processing and Archiving Department.

The project

The J-PAS project began taking the first scientific images about a year ago. It is the main project carried out with the JST250 telescope, a ‘wide-angle’ 2.5 m main mirror, and its JPCam panoramic camera which, with more than 1.2 billion pixels, is currently one of the largest astronomical cameras in the world.

J-PAS is led by the Centro de Estudios de Física del Cosmos de Aragón (CEFCA), together with the Instituto de Astrofísica de Andalucía (IAA-CSIC), the Observatorio Nacional de Rio de Janeiro and the University of Sao Paulo, and is developed and scientifically exploited through an international collaboration with more than 250 researchers from 18 countries.

The J-PAS project was the scientific engine for the definition and construction of the OAJ which, since 2014, belongs to the map of Singular Scientific and Technical Infrastructures (ICTS) of the Ministry of Science, Innovation and Universities. J-PAS is a fundamental part of the project ‘Advanced technologies for the exploration of the Universe and its components’ of the call for Complementary Plans with Autonomous Communities, within the area of Astrophysics and High Energy Physics, funded by the European Union (NextGenerationEU).

The OAJ and the J-PAS project are also funded by the CEFCA and by the Governments of Aragon and Spain through the Teruel Investment Fund, the European Regional Development Funds. The Brazilian agencies FINEP, FAPESP, FAPERJ and the National Observatory of Brazil have contributed to the funding of JPCam. Additional funding for J-PAS has been provided by the Estonian Tartu Observatory and the Chinese J-PAS Astronomical Consortium.

Mosaic generated from the first J-PAS survey data. Credit: David Muniesa/CEFCA.

Cutaway of an area of the deep Universe observed by the J-PAS survey. Credit: Jose Luis Lamadrid/CEFCA.

Press conference to present the first survey data. Crédito: CEFCA

Image of the JPCam camera installed on the Javalambre Survey Telescope (JST250) at the Javalambre Astrophysical Observatory. Credit: CEFCA

Javalambre Survey Telescope (JST250) of the Javalambre Astrophysical Observatory and its scientific instrument JPCam. Credit: CEFCA.