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Gemini Helps Map Larger than Expected Structure of Ancient Supercluster

October 22, 2019

Figure 1: The 3-D and 2-D maps of the number density of galaxies associated with the supercluster. In the 2-D map, the large-scale structures of galaxies located in the slice at about 7.3 billion years ago are shown. The white areas show the structures already known from previous studies, and the yellow areas show the structures newly discovered by this study. The structures marked by the dotted ellipses are to be confirmed by future works. The white vertical line in the figure corresponds to a distance of about 30 million light-years (i.e., 10 Mpc).

In a recent collaborative study, Gemini Observatory and Subaru Telescope uncover the massive (and larger than expected) structure of a distant supercluster. Mapping the formation of these ancient superclusters is a critical step in understanding the dark matter and dark energy that shape these structures. Read an excerpt about this research from Subaru Telescopeʻs science highlight below.

A team of astronomers used the Subaru Telescope and Gemini North telescope to reveal that a well-known distant supercluster is part of a larger structure at least twice as extended as what was already known. The galaxies associated with the supercluster are thought to have formed simultaneously over a vast area and then evolved to their observed states.

Using the Gemini Multi-Object Spectrograph (GMOS) Gemini North telescope and the Faint Object Camera and Spectrograph (FOCAS) on Subaru Telescope, the team has revealed that the supercluster CL1604, a distant supercluster located about 7.3 billion light-years away, is a large-scale 3-D structure extending over about 160 million light-years in the north-south direction. This is more than two times more extended than what was already known. Until now, we saw merely the “tip of the iceberg” of the supercluster. The wide-field capability of the Subaru Telescope enabled us to survey the whole of the supercluster and the Gemini North telescope played a critical role in confirming the structures. This is the outcome of the good synergy of the telescopes of the Maunakea observatories.

Read the full science highlight from Subaru Telescope here.

These results were published in Publications of the Astronomical Society of Japan (Hayashi et al., "The whole picture of the large-scale structure of the CL1604 supercluster at z∼0.9"). A preprint is available here.


Gemini Observatory Participants