English (UK)
How does a galaxy evolve when it has virtually no neighbors for billions of years? That is one of the most fascinating questions in modern astrophysics. To answer it, the international CAVITY project—led by the University of Granada and conducted from the Calar Alto Observatory—has just published the largest homogeneous dataset of three-dimensional observations of galaxies located in so-called cosmic voids.
On July 17, 2026, CAVITY released its second data release (DR2), which includes 200 galaxies observed at Calar Alto using integral-field (or three-dimensional, 3D) spectroscopy—a valuable resource that will allow researchers around the world to study how the most extreme environments in the Universe influence galactic evolution.
Following CAVITY’s first data release (DR1) in July 2024, which included 100 galaxies, the new catalog makes 200 three-dimensional data cubes of galaxies located in cosmic voids available to the entire scientific community. These vast regions of the Universe, where galaxies are scarce, make them an exceptional laboratory for studying how galaxies evolve when the influence of their environment is minimal. With this new release, CAVITY consolidates the largest homogeneous dataset of 3D spectroscopic observations conducted to date on galaxies inhabiting these extreme environments.
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| Images of some representative CAVITY galaxies, illustrating the morphological diversity found in cosmic voids, plotted on a mass (horizontal axis) versus color (vertical axis) diagram. The large, redder elliptical galaxies (top right) can be up to about 500 times more massive than the blue dwarf galaxies (bottom left). Between these two extremes lie numerous spiral galaxies. Credit: Paulo Vásquez-Bustos/CAVIT |
The observations were obtained using the PMAS/PPAK spectrograph installed on the 3.5-meter telescope at the Calar Alto Observatory, which allows for the simultaneous recording of a spectrum at every point in the observed galaxy. Unlike a conventional photograph, these data provide a three-dimensional map containing information on the motion of gas and stars, their chemical composition, star formation, and the evolutionary history of each system.
Since the project began in 2021, CAVITY has collected data on some 300 galaxies, of which the 200 highest-quality ones are now included in this second public release, after undergoing a thorough data reduction and quality control process. This entire process of observations and data analysis is made possible by the work of the Calar Alto Observatory team and the researchers on the CAVITY project.
The first scientific results obtained through CAVITY, and published in recent years, suggest that galaxies in voids evolve more slowly than those in denser regions of the Universe: they form stars over a longer period of time, contain younger stellar populations, and have a different chemical composition. These results are helping us understand the extent to which the cosmic environment influences the evolution of galaxies and provide an ideal testing ground for current models of galaxy formation.
"We hope that this second data release will spur discoveries that go far beyond CAVITY's original objectives and establish the project as an open scientific legacy for the entire astronomical community," says Isabel Pérez, a full professor at the University of Granada and the project's principal investigator.
Jesús Aceituno, director of Calar Alto, emphasizes that “this second public release of CAVITY data is the result of five years of exquisite observations made by the Calar Alto staff, followed by intensive work on the reduction, analysis, and validation of the PMAS spectra by the CAVITY team, demonstrating how astrophysical research based in Andalusia can have a global impact.”
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| Simulation of the distribution of matter in a cubic section of the Universe. Among the blue filaments showing the concentration of matter (primarily in the form of large galaxy clusters, along with their dark matter), the empty regions represent the low-density environments where the CAVITY galaxies are located. Credits: NASA, ESA, and E. Hallman (University of Colorado). |
CONTACTS
- University of Granada (UGr) Isabel Pérez -
This email address is being protected from spambots. You need JavaScript enabled to view it. - Calar Alto observatory (CAHA) Gilles Bergond-
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COMMUNICATION- CALAR ALTO OBSERVATORY
This email address is being protected from spambots. You need JavaScript enabled to view it. - Phone: (+34) 950 632 500
The Calar Alto Observatory is one of the infrastructures that belong to the national map of Unique Scientific and Technical Infrastructures (Spanish acronym: ICTS), approved on March 11th, 2022, by the Science, Technology and Innovation Policy Council (CPCTI).
