Comparison of the Hyperion Proto-Supercluster and a standard massive galaxy cluster
Wide-field view of the COSMOS field
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The Hyperion Proto-Supercluster
Astronomers using ESO’s Very Large Telescope uncover a cosmic titan lurking in the early Universe
Astronomers using ESO’s Very Large Telescope uncover a cosmic titan lurking in the early Universe
An international team of astronomers
using the VIMOS instrument of ESO’s Very Large Telescope have uncovered a
titanic structure in the early Universe. This galaxy proto-supercluster
— which they nickname Hyperion — was unveiled by new measurements and a
complex examination of archive data. This is the largest and most
massive structure yet found at such a remote time and distance — merely 2
billion years after the Big Bang.
A team of astronomers, led by Olga Cucciati of Istituto Nazionale di Astrofisica (INAF) Bologna, have used the VIMOS instrument on ESO’s Very Large Telescope (VLT) to identify a gigantic proto-supercluster
of galaxies forming in the early Universe, just 2.3 billion years after
the Big Bang. This structure, which the researchers nicknamed Hyperion,
is the largest and most massive structure to be found so early in the
formation of the Universe [1].
The enormous mass of the proto-supercluster is calculated to be more
than one million billion times that of the Sun. This titanic mass is
similar to that of the largest structures observed in the Universe
today, but finding such a massive object in the early Universe surprised
astronomers.
“This is the first time that such a large structure has
been identified at such a high redshift, just over 2 billion years
after the Big Bang,” explained the first author of the discovery paper, Olga Cucciati [2]. “Normally
these kinds of structures are known at lower redshifts, which means
when the Universe has had much more time to evolve and construct such
huge things. It was a surprise to see something this evolved when the
Universe was relatively young!”
Located in the COSMOS field in the constellation of Sextans (The Sextant), Hyperion was identified by analysing the vast amount of data obtained from the VIMOS Ultra-deep Survey led by Olivier Le Fèvre (Aix-Marseille Université, CNRS, CNES). The
VIMOS Ultra-Deep Survey provides an unprecedented 3D map of the
distribution of over 10 000 galaxies in the distant Universe.
The team found that Hyperion has a very complex structure, containing at least 7 high-density regions connected by filaments of galaxies, and its size is comparable to nearby superclusters, though it has a very different structure.
“Superclusters closer to Earth tend to a much more concentrated distribution of mass with clear structural features,”
explains Brian Lemaux, an astronomer from University of California,
Davis and LAM, and a co-leader of the team behind this result. “But
in Hyperion, the mass is distributed much more uniformly in a series of
connected blobs, populated by loose associations of galaxies.”
This contrast is most likely due to the fact that nearby
superclusters have had billions of years for gravity to gather matter
together into denser regions — a process that has been acting for far
less time in the much younger Hyperion.
Given its size so early in the history of the Universe,
Hyperion is expected to evolve into something similar to the immense
structures in the local Universe such as the superclusters making up the
Sloan Great Wall or the Virgo Supercluster that contains our own galaxy, the Milky Way. “Understanding
Hyperion and how it compares to similar recent structures can give
insights into how the Universe developed in the past and will evolve
into the future, and allows us the opportunity to challenge some models
of supercluster formation,” concluded Cucciati. “Unearthing this cosmic titan helps uncover the history of these large-scale structures.”
Notes
[1] The moniker Hyperion was chosen after a Titan from Greek mythology,
due to the immense size and mass of the proto-supercluster. The
inspiration for this mythological nomenclature comes from a previously
discovered proto-cluster found within Hyperion and named Colossus. The
individual areas of high density in Hyperion have been assigned
mythological names, such as Theia, Eos, Selene and Helios, the latter being depicted in the ancient statue of the Colossus of Rhodes.
The titanic mass of Hyperion, one million billion times that of the Sun, is 1015 solar masses in scientific notation.
[2] Light reaching Earth
from extremely distant galaxies took a long time to travel, giving us a
window into the past when the Universe was much younger. This wavelength
of this light has been stretched by the expansion of the Universe over
its journey, an effect known as cosmological redshift. More distant,
older objects have a correspondingly larger redshift, leading
astronomers to often use redshift and age interchangeably. Hyperion’s
redshift of 2.45 means that astronomers observed the proto-supercluster
as it was 2.3 billion years after the Big Bang.
More Information
Contacts
Olga Cucciati
INAF Fellow – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
Bologna, Italy
Email: olga.cucciati@inaf.it
Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email: pio@eso.org
More Information
This research is
published in the paper “The progeny of a Cosmic Titan: a massive
multi-component proto-supercluster in formation at z=2.45 in VUDS”,
which will appear in the journal Astronomy & Astrophysics.
The team behind this result was composed of O. Cucciati
(INAF-OAS Bologna, Italy), B. C. Lemaux (University of California,
Davis, USA and LAM - Aix Marseille Université, CNRS, CNES, France), G.
Zamorani (INAF-OAS Bologna, Italy), O.Le Fèvre (LAM - Aix Marseille
Université, CNRS, CNES, France), L. A. M. Tasca (LAM - Aix Marseille
Université, CNRS, CNES, France), N. P. Hathi (Space Telescope Science
Institute, Baltimore, USA), K-G. Lee (Kavli IPMU (WPI), The University
of Tokyo, Japan, & Lawrence Berkeley National Laboratory, USA), S.
Bardelli (INAF-OAS Bologna, Italy), P. Cassata (University of Padova,
Italy), B. Garilli (INAF–IASF Milano, Italy), V. Le Brun (LAM - Aix
Marseille Université, CNRS, CNES, France), D. Maccagni (INAF–IASF
Milano, Italy), L. Pentericci (INAF–Osservatorio Astronomico di Roma,
Italy), R. Thomas (European Southern Observatory, Vitacura, Chile), E.
Vanzella (INAF-OAS Bologna, Italy), E. Zucca (INAF-OAS Bologna, Italy),
L. M. Lubin (University of California, Davis, USA), R. Amorin (Kavli
Institute for Cosmology & Cavendish Laboratory, University of
Cambridge, UK), L. P. Cassarà (INAF–IASF Milano, Italy), A. Cimatti
(University of Bologna & INAF-OAS Bologna, Italy), M. Talia
(University of Bologna, Italy), D. Vergani (INAF-OAS Bologna, Italy), A.
Koekemoer (Space Telescope Science Institute, Baltimore, USA), J. Pforr
(ESA ESTEC, the Netherlands), and M. Salvato (Max-Planck-Institut für
Extraterrestrische Physik, Garching bei München, Germany).
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Links
Links
Contacts
Olga Cucciati
INAF Fellow – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
Bologna, Italy
Email: olga.cucciati@inaf.it
Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email: pio@eso.org
Source: ESO/News
