Ten thousand million year of cosmic evolution at hand

2013-11-13 10:30
ALHAMBRA Survey. Processed by: V. Peris.

ALHAMBRA Survey. Processed by: V. Peris.

The complete catalog of ALHAMBRA project will be published tomorrow. It consists on a mapping of the space to study the evolution of the universe over the last ten billion years.

ALHAMBRA has identified, classified and calculated the distance of more than half a million galaxies spread over eight regions of the sky. The development of this catalog has been performed by the Observatorio de Calar Alto with the collaboration of researchers of the Centro de Estudios de Física del Cosmos de Aragón.

ALHAMBRA (Advanced Large, Homogeneous Area Medium Band Redshift Astronomical survey) is the result of seven years of accurate observations of the universe from the Calar Alto Observatory (CAHA, Almería). Thanks to a technique that breaks the energy of the stars in their colors using astronomical filters, ALHAMBRA could identify and classify more than half a million galaxies, and also calculate their distances to the earth with amazing accuracy. As a result, the ALHAMBRA survey represents the most realistic three-dimensional view of the universe.

The ALHAMBRA mapping is an ambitious scientific project that involves scientists of sixteen research institutes worldwide. Led by the director of CEFCA, Dr. Mariano Moles, the ALHAMBRA project was designed to trace the evolution of the universe over the last ten billion years.

Dr. Mariano Moles, lead researcher of ALHAMBRA project, says that “ALHAMBRA will be crucial to address the pressing problems of cosmology and astrophysics using a photometric mapping of the space. It will provide the required accuracy in the calculation of the distance of the detected objects. Thus, the unbiased nature of this mapping will allow obtaining relevant data for all cosmic scales. Therefore, the ALHAMBRA project is a forerunner of the new long-range mappings that are being proposed.”

A mapping for all scales

On the one hand, the vision of the universe provided by ALHAMBRA will allow studying how the stellar content has changed over time: How, when and how much has the stellar content aged? It will also be possible to set a clear relationship between the morphology, the content of the stars and the age of the galaxies in order to determine the physical processes that govern the universe at these scales.

On the other hand,with the results of the ALHAMBRA project it will be possible to determine how galaxies are distributed in the universe. "In the past thirteen billion years, gravity has been responsible for the formation of structures such as galaxies or stars," says Alberto Molino, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC), who is a member of the ALHAMBRA team. “The study of the distribution of the galaxies allows us to determine the physical properties that ruled the universe in the past. It would be like if just by examining the trees of a forest that we can see today, we could know the exact place and conditions in which the seeds of the trees were planted" illustrates the researcher.

The observations conducted within the ALHAMBRA project have traversed vast areas of our galaxy. In this way, the investigation of the cosmic history of the Milky Way will allow developing a census of stars, discovering variable stars, determining the frequency at which stars are paired or identifying candidate stars to host other planets.

500,000 galaxies to everyone

The imminent release of the data will allow the international scientific community, universities, science museums, astronomical associations and schools worldwide to benefit from the results of the ALHAMBRA project.

The scientific value of this project converts it in an international reference in the study of the galaxy properties. This project will be the basis of future mapping studies like J-PAS (Javalambre Physics of the Accelerating Universe Astrophysical Survey) that will extend the study from a few regions of the sky to the entire observable universe.

Finally, ALHAMBRA has served to prove, once again, the crucial role of the Spanish astronomical observatories. Particularly, the Calar Alto Observatory, which has proven to be an essential facility able to provide the most accurate and representative view of our universe so far.

“It is mandatory to acknowledge and recognize the effort and ability of Calar Alto staff. They have made it possible to record the data of ALHAMBRA project in the best possible conditions” highlights Dr. Moles.