A Proto-Supercluster of Galaxies Hosting a Massive Galaxy Cluster 10 Billion Light Years Away
Ripon Saha, Mark Brodwin, IDCS Collaboration University of Missouri – Kansas City
236TH MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY Press Conference: Galaxies Weird & Wonderful June 01, 2020
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Galaxy Clusters
• The most massive gravitationally bound structures up to a million billion times the mass of the sun.
• Clusters started forming via gravity-driven mergers and accretion of smaller groups of galaxies about more than 12 billion years ago.
• The process of formation also creates an intracluster medium (ICM) of hot and Brodwin et al. 2016 dense ionized gas. The Galaxy Cluster IDCS J1426.5+3508 in Boötes as seen by the Great Observatories Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Galaxy Protoclusters
• Protoclusters are the progenitors of galaxy clusters.
• They are extended structures that will collapse into galaxy clusters by the present day.
• Normally, protoclusters do not have hot intracluster gas. Toshikawa et al. 2018
Examples of Protoclusters
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Current Status of Galaxy Cluster & Protocluster Searches
Today Big Bang (Billions of year)
Overzier & Kashikawa 2020
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Current Status of Galaxy Cluster & Protocluster Searches
Today Big Bang (Billions of year)
Overzier & Kashikawa 2020
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Current Status of Galaxy Cluster & Protocluster Searches
Today Big Bang
The most massive cluster in the distant universe at z = 1.75 (Stanford et al. 2012, Brodwin et al. 2016) Redshift, z = 1.75 Overzier & Kashikawa 2020
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Identifying Galaxy Clusters/Protoclusters using Dust-obscured Galaxies as Signposts
• Dust-Obscured Galaxies (DOGs) are optically very faint, infrared-bright galaxies.
• Generally, DOGs are highly star-forming and/or galaxies with active supermassive black holes (SMBH). They are located between redshift 1.5 – 2.5.
• Many studies in the last decade have indicated that distant galaxy clusters and protoclusters exhibit enhanced star formation and SMBH accretion in their DOGs live here !!! cores.
• We test this hypothesis by employing DOGs as signposts to detect distant large-scale structures.
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Identifying Galaxy Clusters/Protoclusters using Dust-obscured Galaxies as Signposts
KPNO B, I + Spitzer 4.5 um Brodwin et al. 2016
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Identifying Galaxy Clusters/Protoclusters using Dust-obscured Galaxies as Signposts
Rediscovery !!! Brodwin et al. 2016 KPNO B, I + Spitzer 4.5 um Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies 10 Billion Light Years Away
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) A Proto-Supercluster of Galaxies at Redshift, z = 1.75
Recap
1. We have verified that DOGs are good tracers of structures in the distant universe.
2. We have recovered known galaxy clusters 10 billion light years away, and found that these are still embedded in their ancestral protocluster birth structure.
3. Studies like this will allow us to understand the full evolutionary lifecycles of the massive structures in the universe.
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) Questions? iPoster Plus Session II: Galaxy Clusters 127.03 Monday, 06/01/2020 4:10 PM EDT
Ripon Saha Physics & Astronomy University of Missouri Kansas City [email protected] 816.844.2595
Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)