Subj : Daily APOD Report To : All From : Ben Ritchey Date : Tue Feb 26 2019 10:44:51 Astronomy Picture of the Day Astronomy Picture of the Day Discover the cosmos! [1] Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2019 February 26 Simulation TNG50: A Galaxy Cluster Forms Video Credit: IllustrisTNG Project [2] ; Visualization: Dylan Nelson [3] ( Max Planck Institute for Astrophysics [4] ) et al. Music: Symphony No. 5 [5] ( Ludwig van Beethoven [6] ), via YouTube Audio Library [7] Explanation: How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. A recent effort is TNG50 [8] from IllustrisTNG [9] , an upgrade of the famous Illustris Simulation [10] . The first part of the featured video [11] tracks cosmic gas (mostly hydrogen [12] ) as it evolves into galaxies [13] and galaxy clusters [14] from the early universe to today, with brighter colors marking faster moving gas. As the universe matures, gas falls into gravitational wells [15] , galaxies forms, galaxies spin, galaxies collide and merge, all while black holes form in galaxy centers [16] and expel surrounding gas at high speeds. The second half of the video [17] switches to tracking stars, showing a galaxy cluster coming together complete with tidal tail [18] s and stellar streams [19] . The outflow from black holes in TNG50 [20] is surprisingly complex [21] and details are being compared with our real universe [22] . Studying how [23] gas coalesced in the early universe [24] helps humanity better understand how our Earth [25] , Sun [26] , and Solar System [27] originally formed. Tomorrow's picture: horse-belt orange ------------------------------------------------------------------------------- < [28] | Archive [29] | Submissions [30] | Index [31] | Search [32] | Calendar [33] | RSS [34] | Education [35] | About APOD [36] | Discuss [37] | > [38] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [39] (MTU [40] ) & Jerry Bonnell [41] (UMCP [42] ) NASA Official: Phillip Newman Specific rights apply [43] . NASA Web Privacy Policy and Important Notices [44] A service of: ASD [45] at NASA [46] / GSFC [47] & Michigan Tech. U. [48] ---------- Site notes: [1] archivepix.html [2] http://www.tng-project.org/people/ [3] https://wwwmpa.mpa-garching.mpg.de/~dnelson/ [4] https://www.mpa-garching.mpg.de/ [5] https://en.wikipedia.org/wiki/Symphony_No._5_(Beethoven) [6] https://en.wikipedia.org/wiki/Ludwig_van_Beethoven [7] https://www.youtube.com/audiolibrary/music [8] http://www.tng-project.org/about/ [9] http://www.tng-project.org/ [10] http://www.illustris-project.org/ [11] http://www.tng-project.org/media/ [12] https://periodic.lanl.gov/1.shtml [13] ap181009.html [14] https://en.wikipedia.org/wiki/Galaxy_cluster [15] https://en.wikipedia.org/wiki/Gravity_well [16] ap991017.html [17] http://www.tng-project.org/media/ [18] ap100926.html [19] ap140117.html [20] https://arxiv.org/abs/1902.05553 [21] http://playworkschicago.com/wp-content/uploads/2018/04/Picture1.jpg [22] ap180305.html [23] https://arxiv.org/abs/1902.05554 [24] https://jwst.nasa.gov/firstlight.html [25] https://solarsystem.nasa.gov/planets/earth/in-depth/ [26] https://solarsystem.nasa.gov/solar-system/sun/in-depth/ [27] https://www.solarsystemscope.com/ [28] ap190225.html [29] archivepix.html [30] lib/apsubmit2015.html [31] lib/aptree.html [32] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [33] calendar/allyears.html [34] /apod.rss [35] lib/edlinks.html [36] lib/about_apod.html [37] http://asterisk.apod.com/discuss_apod.php?date=190226 [38] ap190227.html [39] http://www.phy.mtu.edu/faculty/Nemiroff.html [40] http://www.phy.mtu.edu/ [41] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [42] http://www.astro.umd.edu/ [43] lib/about_apod.html#srapply [44] https://www.nasa.gov/about/highlights/HP_Privacy.html [45] https://astrophysics.gsfc.nasa.gov/ [46] https://www.nasa.gov/ [47] https://www.nasa.gov/centers/goddard/ [48] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .