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The largest two-dimensional map of the sky continues to grow

03 мая 2024

The largest two-dimensional map of the sky continues to grow

The largest two-dimensional map of the sky ever created has become even larger thanks to the tenth release of data obtained during the DESI Legacy Imaging Surveys study. This is a monumental scan of the universe that lasted more than six years and analyzed almost half of the sky. The new data were obtained as a result of the analysis of images in the infrared wavelength range and new observed areas of the sky.

The universe consists of billions of galaxies, each filled with billions of stars. Although all galaxies are very bright, from Earth they look like faint blurred spots. The reason for this lies both in the large amount of dust contained in the galactic disks and in the distance separating us from them.

By creating complete maps of even the faintest and most distant galaxies, astronomers can study the structure of the universe and uncover the mysterious properties of dark matter and dark energy. Thanks to the tenth publication of data from the spectroscopic instrument for the study of dark energy (DESI), the largest map to date has become even larger.


Resources used

The DESI Legacy Imaging Survey expands on data included in two previous sky surveys: the Dark Energy Camera (DECam) Legacy Survey and the Beijing-Arizona Sky Survey. These three surveys covered a total of 14,000 square degrees of visible sky in the northern hemisphere using telescopes at Kitt Peak National Observatory NOIRLab and the Cerro Tololo Inter-American Observatory in Chile.

This ambitious six-year project involved three telescopes and produced a petabyte (1,000 trillion bytes) of data. The data was processed by one of the most powerful computers in the world, located at the U.S. Department of Energy's National Energy Research Computing Center. The result of these efforts was the largest two-dimensional map of the sky ever created. Telescope data collection cameras include:

The Mosaic-3 camera on the Nicholas U. Mayall telescope is 4 meters in diameter.
The 90Prime camera on the 2.3 meter diameter Bok telescope at the University of Arizona.
A camera for studying dark energy, created by the US Department of Energy (DECam), on the 4-meter Víctor M. Blanco telescope at CTIO in Chile.


The purpose of mapping

One of the main mapping goals is to identify about 40 million target galaxies for the DESI spectroscopic survey. The goal is to understand dark energy by accurately mapping the history of the expansion of the universe over the past 12 billion years.

The team is trying to create as complete a map of the sky as possible. To include new elements, more images have been added and data processing has been improved. In particular, the tenth data set released is dedicated to the integration of new images of the southern part of the extragalactic sky obtained using DECam. Areas far from the Milky Way disk were especially carefully mapped to avoid the dense dust of our galaxy, which could obscure part of the signal.


Screenshot_20A large plan of the camera for the study of dark energy (DECam) during its assembly in a clean room SiDet. The Dark Energy Camera was designed specifically for the study of dark energy. It was funded by the Department of Energy (DOE) and was built and tested in Fermilab.


With the addition of the latest data, Legacy Imaging Surveys has been expanded to more than 20,000 square degrees, or almost half of the sky. The new version includes images obtained using an additional filter capable of selecting infrared light. “Adding infrared data will allow us to better calculate the redshift of distant galaxies, or the time it takes light from these galaxies to reach Earth,“ said Alfredo Zenteno, NOIRLab astronomer and principal investigator of the DECam eROSITA Survey.

It's not just scientists who benefit from the growing archive of astronomical data generated by Legacy Surveys. The data that is publicly available at this link allows astronomy enthusiasts and curious people to study the universe around us in a digital format.

“Anyone can use survey data to explore the sky and make discoveries,“ explained Arjun Dey, astronomer at NOIRLab. “In my opinion, it is this ease of access that has made the research so effective. We hope that in a few years Legacy Surveys will have the most complete map of the entire sky and will become a treasure trove for scientists in the future.“

Source: new-science.ru