Almost two million objects to study dark energy

2023-06-13 16:50:08

The universe is extremely large and does not stop growing. To study the dark energythat mysterious force behind the accelerating expansion of the Universe, scientists have begun to use the Dark Energy Spectroscopic Instrument (DESIfor its acronym in English), which will map more than 40 million galaxies, quasars and stars from the Mayall telescope, installed in the Kitt Peak Observatory in Arizona (United States).

The collaboration of this project has made public this Tuesday its first data package, which includes almost two million objects for further analysis.

First Dark Energy Spectroscopic Instrument (DESI) data package delivers 80 terabytes from more than 2,400 exposures

The data set covers 80 terabytes fruit of more than 2,400 exhibitions obtained over six months during the “project validation” phase in 2020 y 2021. In this period, between the commissioning of the instrument and the start of official science operations, the researchers ensured that the observation schedule is in line with the scientific objectives of the project, checking how long it took to observe galaxies of different sizes. brightness and validating the selection of objects to observe.

“The fact that DESI works so well, and that the amount of quality data it collected during the validation phase is comparable to the totality of data from previous projects, is a monumental achievement,” he says. Nathalie Palanque-Delabrouilleone of the spokespersons for DESI and a scientist at the Lawrence Berkeley National Laboratory (Berkeley Lab) of the US Department of Energy, which manages the experiment.

“This milestone demonstrates that DESI is a unique spectroscopic factory whose data will not only enable the study of dark energy, but will also be required by the entire scientific community to address other topics such as dark matter, gravitational lensingand the galactic morphology”, he added.

DESI’s 5,000 robotic positioners can measure the light from more than 100,000 galaxies in one night

ALTHOUGH use 5,000 robotic positioners to move the optical fibers that collect light from astronomical objects. It is the most powerful multi-object spectrograph in the world, capable of measuring the light of more than 100,000 galaxies in one night. That light tells researchers how far away each galaxy is, making it possible to build a 3D cosmic map.

Los first data they are freely and openly available through the National Energy Research Scientific Computing Center (NERSC). In the same way, it is also possible to view a video on the internet that shows its operation.

DESI is supported by the Office of Science of the United States Department of Energy (DOE) and NERSC, which is an infrastructure of the Office of Science of this department.

It also has additional support from the US National Science Foundation, the UK Council for Science and Technology Facilities, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation, the Atomic Energy and Alternative Energy Commission ( CEA) of France, the National Council of Science and Technology of Mexico, the Ministry of Science and Innovation of Spain and the member institutions of DESI.

Spanish participation

From Spain, the Center for Energy, Environmental and Technological Research (VILLAGE), the Institute of Space Sciences (ICE-CSIC), the Institute of Space Studies of Catalonia (IEC), the Institute of High Energy Physics (IFAE), the Institute of Theoretical Physics (IFTjoint center of the Autonomous University of Madrid and the CSIC), the Institute of Astrophysics of Andalusia (IAA-CSIC), the Instituto de Astrofísica de Canarias (IAC) and the Institute of Cosmos Sciences of the University of Barcelona (ICCUB).

Regarding the Kitt Peak National Observatory, it is a program of the NOIRLab of the National Science Foundation (NSF) of the USA. The DESI collaboration highlights that they have allowed it to conduct scientific research on Iolkam Du’ag (Kitt Peak), a mountain of special significance for a North American indigenous people: the Tohono O’odham Nation .

Reactions from Spain

“It is impressive that, in just a few months, DESI has measured positions for more objects than all previous cosmic mappers,” he says. Violet Gonzalez Perez, a researcher at the Department of Theoretical Physics of the Autonomous University of Madrid, “the data that is now made public will allow us to better understand the nature of dark energy with mathematical tools that have not been used until now. And we will also be able to explore the earliest moments of the universe, the mass of neutrinos, the history of our galaxy, and the formation and evolution of galaxies and quasars.”

“During the mapping validation phase, we visually inspect the spectra obtained to confirm the quality of the observations and their classification among stars, bright galaxies, luminous red galaxies, galaxies with emission lines, and quasars,” he says. Ignasi Pérez and Ràfolsscientist at the Institute of Cosmos Sciences at the University of Barcelona.

“DESI is designed to observe regions already explored with other methods,” he points out. Cesar Ramirez Perezpre-doctoral researcher at the Institut de Física d’Altes Energies, “so it will help to complement previous analyses, and with the publication of the data we get groups outside the collaboration to access them, expanding their impact.”

Malgorzata Siudek, a postdoctoral researcher at the Institute of Space Sciences in Barcelona, ​​comments: “DESI’s observations are much more precise than previous surveys, making it possible to observe all kinds of extragalactic objects, including quasars formed shortly after the Big Bang. The discovery of such rare objects is not only an important advance in itself, but also allows us to study the mystery of the formation of supermassive black holes.”

For its part, at the Instituto de Astrofísica de Canarias (IAC) there are two teams participating in this project. One of them is led by Francisco-Shu Kitaurawho comments: “The distribution of galaxies analyzed by the DESI instrument will shed light on how the largest structures in the universe were formed, which can be used to study the origin and basic components of the cosmos.”

The director of the other IAC team, Carlos Allende Prietoadds: “Our interest is particularly focused on the formation of the first stars in the universe”, in addition to indicating that they have used the Gran Telescopio Canarias “to verify the agreement of the data obtained by both scientific infrastructures”.

Fuente: IAC/NSF’s NOIRLab/IFT (UAM/CSIC)

Rights: Creative Commons.