For a long time, astronomers have been striving to create a map of the night sky, not only to enhance our understanding of the universe we live in but also to support further research. These comprehensive catalogs of celestial objects serve various scientific purposes related to astronomy and astrophysics.
However, these scientific resources need periodic updates to reflect the ongoing technological advancements in telescopes. In this context, astronomers have created an atlas detailing nearly 400,000 galaxies in our cosmic neighborhood.
The atlas, named the “Sienna Atlas of Galaxies,” was compiled using data from the NOIRLab’s telescopes, affiliated with the National Science Foundation. It is designed to be the dedicated digital atlas for large galaxies, providing a treasure trove of information for researchers studying everything from galaxy formation and evolution to dark matter and gravitational waves. Moreover, it is freely accessible online for the public to explore. This atlas has been presented in a research paper published in the Astrophysical Journal Supplement Series.
Summary of Three Surveys
The Sienna Atlas of Galaxies is a compilation of data from three surveys conducted between 2014 and 2017, carried out at the Cerro Tololo Inter-American Observatory, Kitt Peak National Observatory, both part of the NOIRLab, and Stewart Observatory at the University of Arizona.
These surveys utilized state-of-the-art instruments in NOIRLab-operated telescopes, and the survey data, along with a queryable version of the full Sienna Atlas of Galaxies, have been made available to the astronomical community through the Astro Data Lab platform and the NOIRLab Community Science and Data Center.
The Sienna Atlas of Galaxies includes additional data from a survey conducted by NASA’s Wide-field Infrared Survey Explorer (WISE), a wide-ranging infrared space telescope. This data was reprocessed by Aaron Meisner, an astronomer at NOIRLab.
These surveys captured images in optical and infrared wavelengths to chart an area totaling 20,000 square degrees, roughly equivalent to half of the night sky, making it one of the largest galaxy surveys.
By consolidating this wealth of information in one place, the Sienna Atlas of Galaxies provides precise data on the positions, shapes, and sizes of hundreds of thousands of relatively nearby large galaxies. Additionally, the data in the atlas achieves a new level of accuracy.
A Celestial Mosaic of 42 Galaxies in the Sienna Atlas of Galaxies (NOIRLab – National Science Foundation)
An Atlas for Researchers and the General Public
The Sienna Atlas of Galaxies builds upon centuries of efforts to map the night sky. The famous “Catalog of Nebulae and Clusters of Stars” published by French astronomer Charles Messier in 1774 was a notable landmark, as was the “New General Catalog of Nebulae and Clusters of Stars” published by John Louis Emil Dreyer in 1888.
In 1991, astronomers compiled the “Third Reference Catalog of Bright Galaxies,” and several valuable galaxy atlases have been published in the past two decades. However, most of them relied on photographic plate measurements in the Third Reference Catalog of Bright Galaxies or lacked data on a significant number of galaxies. The Sienna Atlas of Galaxies represents a significant improvement in data quality and completeness as it utilizes digitally captured images from highly sensitive instruments.
Argon Day, an astronomer at NOIRLab who was involved in the project, explained in a press release on the Phys.org website that previous galaxy catalogs suffered from inaccurate positions, sizes, and shapes of galaxies and even included information about objects that were not galaxies, such as stars or other celestial bodies. The Sienna Atlas of Galaxies surpasses all these limitations.
This versatile resource advances various branches of astronomy and astrophysics by assisting scientists in finding the best galaxy samples for observation and study. Importantly, the atlas is not limited to academic researchers; it is freely available online for anyone interested in gaining a better understanding of our corner of the cosmos.
