Hyperion proto-supercluster

{{Short description|Galaxy cluster in the constellation Sextans}}

{{Infobox galaxy cluster

| name = Hyperion proto-supercluster

| image = The Hyperion Proto-Supercluster.jpg

| image_scale = 2

| caption = Visualization of the Hyperion proto-supercluster

| credit =

| epoch = J2000

| constellation = Sextans

| ra = {{RA|10|6}}

| dec = {{DEC|2.3}}

| brightest_member =

| member_no =

| major_axis_mpc = {{convert|150|Mpc|Mly|0|abbr=on|lk=on}}

| minor_axis_mpc = {{convert|60|Mpc|Mly|0|abbr=on|lk=on}}

| redshift = 2.45

| distance =

| mass = {{val|4.8|e=15}}

| luminosity =

| flux =

| other_names =

}}

The Hyperion proto-supercluster is the largest and earliest known proto-supercluster, 5,000 times the mass of the Milky Way and seen at 20% of the current age of the universe. It was discovered in 2018 by analysing the redshifts of 10,000 objects observed with the Very Large Telescope in Chile.

Discovery

The discovery was announced in late 2018.{{citation|work=Newsweek|via=MSN|title=Astronomers Find Largest Galaxy Proto-supercluster|author=Katherine Hignett|date=October 17, 2018|url=https://www.msn.com/en-us/news/technology/astronomers-find-largest-galaxy-proto-supercluster/ar-BBOvra5}}{{citation|title=Largest Galaxy Proto-Supercluster Found – Astronomers using ESO's Very Large Telescope uncover a cosmic titan lurking in the early Universe |url=https://www.eso.org/public/news/eso1833/ |publisher=European Southern Observatory (ESO)|id=Science Release eso1833 |date=17 October 2018|access-date=18 October 2018}}

The discovery team led by Olga Cucciati used computational astrophysics methods and astroinformatics; statistical techniques were applied to large datasets of galaxy redshifts, using a two-dimensional Voronoi tessellation to correlate gravitational interaction (virialization) of visible structures.{{sfn|Cucciati|Lemaux|Zamorani|Le Fèvre|2018}} The existence of non-visible (dark matter) structures was inferred.{{cn|date=November 2018}}

Correlation was based on redshift data captured in a sky survey called VIMOS-VLT Deep Survey, using the Visible Multi Object Spectrograph (VIMOS) instrument of the Very Large Telescope in Chile, and other surveys to a lesser extent. Spectroscopic redshift data for 3,822 objects (galaxies) was selected.{{sfn|Cucciati|Lemaux|Zamorani|Le Fèvre|2018|p=3}}

The discovery was published in Astronomy & Astrophysics in September 2018.

Physical description

The structure is estimated to weigh 4.8 × 10¹⁵ solar masses (about 5,000 times the mass of the Milky Way{{citation|title=This 'supercluster' of galaxies lets us peek into the universe's past

|author=Don Lincoln

|date=October 21, 2018

|publisher=CNN

|url=https://www.cnn.com/2018/10/21/opinions/hyperion-supercluster-opinion-lincoln/index.html}}) and to extend {{convert|60x60x150|Mpc|Mly|0|abbr=on|lk=on}}.{{sfn|Cucciati|Lemaux|Zamorani|Le Fèvre|2018|p=1}}{{citation|publisher=CBC|date=October 17, 2018|title=Astronomers find most massive structure in the early universe: Proto-supercluster may contain thousands of galaxies|author=Nicole Mortillaro|url=https://www.cbc.ca/news/technology/proto-supercluster-galaxies-1.4865301}} It lies within the two square degree Cosmic Evolution Survey (COSMOS) field of the constellation Sextans.{{cite web|website=Space.com|title=Meet Hyperion: Colossal Supercluster in the Early Universe

|author= Doris Elin Salazar | date=October 17, 2018 |url=https://www.space.com/42173-hyperion-supercluster-discovered-early-universe.html}} Hyperion's redshift is z=2.45{{sfn|Cucciati|Lemaux|Zamorani|Le Fèvre|2018|p=1}} putting it 11 billion light years from Earth; it existed at less than 20% of the present age of the Universe.{{citation|work=Reuters|title=Scientists in Chile unveil 'A Cosmic Titan' cluster of galaxies|date=October 17, 2018|author=Natalia A. Ramos Miranda|url=https://www.reuters.com/article/us-space-galaxy/scientists-in-chile-unveil-a-cosmic-titan-cluster-of-galaxies-idUSKCN1MR2RS}} Eventually it 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".{{citation|title=Astronomers Find A Cosmic Titan In The Early Universe|work=Keck Observatory News|publisher=W. M. Keck Observatory, California Association for Research in Astronomy|location=Kamuela, Hawaii|type=website|date=October 19, 2018|url=http://keckobservatory.org/hyperion/|access-date=2018-11-22}}

Use in cosmology

The supercluster contains dark matter, evidenced by a mismatch between the visible objects in it and their computed gravitational binding. As a relic from the early Universe, the dark matter data could be used to test cosmological theories. As the 2018 paper authors note, "the identification of massive/complex proto-clusters at high redshift could be useful to give constraints on dark matter simulations" of the Lambda-CDM model.{{sfn|Cucciati|Lemaux|Zamorani|Le Fèvre|2018|p=17}}

References

Sources

{{Cite journal|doi=10.1051/0004-6361/201833655|title=The progeny of a cosmic titan: A massive multi-component proto-supercluster in formation at z = 2.45 in VUDS|journal=Astronomy & Astrophysics|volume=619|pages=A49|year=2018|last1=Cucciati|first1=O.|last2=Lemaux|first2=B. C.|last3=Zamorani|first3=G.|last4=Le Fèvre|first4=O.|last5=Tasca|first5=L. A. M.|last6=Hathi|first6=N. P.|last7=Lee|first7=K.-G.|last8=Bardelli|first8=S.|last9=Cassata|first9=P.|last10=Garilli|first10=B.|last11=Le Brun|first11=V.|last12=MacCagni|first12=D.|last13=Pentericci|first13=L.|last14=Thomas|first14=R.|last15=Vanzella|first15=E.|last16=Zucca|first16=E.|last17=Lubin|first17=L. M.|last18=Amorin|first18=R.|last19=Cassarà|first19=L. P.|last20=Cimatti|first20=A.|last21=Talia|first21=M.|last22=Vergani|first22=D.|last23=Koekemoer|first23=A.|last24=Pforr|first24=J.|last25=Salvato|first25=M.|arxiv=1806.06073|bibcode=2018A&A...619A..49C|s2cid = 119472428}}