Published the new J-PLUS catalog, with almost twenty million celestial objects

The Javalambre Photometric Local Universe Survey (J-PLUS) collaboration concludes today its third virtual scientific meeting, in which the results and scientific analysis carried out with the data from the J-PLUS mapping, which is carried out with the JAST/T80 telescope of the Javalambre Astrophysical Observatory, have been shown. The meeting, organized by the Center for the Study of Physics of the Cosmos of Aragon (CEFCA), has had the participation of seventy scientists from more than twenty institutions, and at the end the new data catalog has been released, which contains 19.5 million objects.

This data set (or DR2, from data release 2) collects the observations made from the end of 2015 to the beginning of 2020. They add up to 2200 square degrees of the sky, which includes the DR1 (July 2018) re-analyzed with improvements in data quality and calibration, and more than 1000 new square degrees. Of the 19.5 million objects observed in high quality, approximately six million are galaxies and 13.5 million are stars. The data provides scientific information on twelve bands of light, with measurements of more than a thousand parameters per object, including photometric measurements, stellar atmospheric parameters (temperature and metallicity), and also distance calculations for galaxies.

Ongoing research with the new data covers various fields of astronomy, including work on the Solar System, the Milky Way, nearby galaxies, and cosmology. The program of the meeting has included projects on searches for very low metallicity stars, star formation processes, detection of new asteroids, search for new planetary nebulae, studies of white dwarfs and cataclysmic variable stars, studies of stellar populations, etc.

Other legacy projects made with the JAST/T80 telescope have also been featured: the GALANTE and J-VAR projects. These are two complementary projects to the J-PLUS survey, which plan to indiscriminately observe several thousand square degrees of the sky with twelve optical filters. GALANTE focuses its observations on the disk of our galaxy, with the aim of making an unprecedented census of hot and massive stars. J-VAR observes the sky already observed by J-PLUS at eleven different times, with the aim of determining how the brightness of objects varies over time and detecting and studying supernovae and variable stars, among others.

“We are very satisfied with the amount of work presented. The variety of contributions shows the transversality of the data provided by the telescope to carry out research in different fields of astronomy -explains Dr. Carlos López San Juan, CEFCA researcher and scientific coordinator of the J-PLUS project-. Fourteen scientific papers have been published to date and several dozen are in preparation within the framework of collaboration with the new data now being made public. This highlights the potential of the data provided by the OAJ telescopes for the advancement of scientific knowledge and the effort made by CEFCA to produce data of the highest scientific quality”, he adds.

"This new catalog associated with DR2 will contain several million galaxies with observations in twelve photometric and redshift bands. These data will allow us to carry out studies on the evolution of galaxies and, in particular, on the effect of the environment on the spatially resolved properties of closest galaxies, as well as in the evolution with the redshift of the integrated properties of the most distant galaxies", highlights Rosa González Delgado, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC) participating in the project.

The J-PLUS project has been financed by the Teruel Investment Fund, the Government of Aragon, the Ministry of Science, Innovation and Universities, the State Research Agency and the FEDER, the latter through ICTS-2009-14, AYA2012–30789, AYA2015-66211 and PGC2018-097585-B-C21 grants. The Brazilian funding agency FAPESP and the Rio de Janeiro National Observatory have contributed to the construction of the T80Cam camera of the JAST / T80 telescope with which the survey is carried out.