00:02visit chandra's beautiful universe x arithmetic
00:10galaxy clusters are the most massive objects in the universe held together by gravity containing
00:16up to several thousand individual galaxies and huge reservoirs of superheated x-ray emitting gas
00:23the mass of this hot gas is typically about five times higher than the total mass of all
00:28the galaxies in galaxy clusters in addition to these visible components 80 of the mass of galaxy
00:35clusters is supplied by dark matter these cosmic giants are bellwethers not only for the galaxies
00:41stars and black holes within them but also for the evolution and growth of the universe itself
00:48nasa's chandra x-ray observatory has observed many galaxy clusters over the lifetime of the mission
00:55chandra's x-ray vision allows it to see the enormous stockpiles of hot cluster gas with temperatures
01:01as high as 100 million degrees with exquisite clarity this blazing gas tells stories about past
01:08and present activity within galaxy clusters many of these galaxy clusters host supermassive black
01:15holes at their centers which periodically erupt in powerful outbursts these explosions generate jets
01:22that are visible in radio wavelengths which inflate bubbles full of energetic particles these bubbles
01:28carry energy out into the surrounding gas chandra's images have revealed a wealth of other structures
01:35formed during these black hole outbursts including hooks rings arcs and wings however appearances
01:43alone don't tell us what these structures are or how they formed to tackle this problem a team of
01:49astronomers developed a novel image processing technique to analyze x-ray data allowing them to
01:55identify features in the gas of galaxy clusters like never before classifying them by their nature
02:01rather than just their appearance prior to this technique which they call x arithmetic scientists could
02:08only identify the nature of some of the features and in a much less efficient way via studies of the
02:14amounts of x-ray energy dispersed at different wavelengths the authors applied x arithmetic to
02:2015 galaxy clusters and galaxy groups galaxy groups are similar to galaxy clusters but with fewer member
02:27galaxies by comparing the outcome from the x arithmetic technique to computer simulations researchers now have
02:35a new tool that will help in understanding the physical processes inside these important titans of the universe
02:42the researchers were able to classify features in the galaxy clusters and groups into three distinct
02:47types which they have colored differently by splitting chandra data into lower energy and higher energy x-rays
02:54and comparing the strengths of each structure and both the physical features included bubbles sound waves
03:01and cooler or slower moving gas there are still many open questions about these black hole outbursts
03:08for example scientists would like to know how much energy they put into the gas around them and how often
03:14they occur these violent events play a key role in regulating the cooling of the hot gas and controlling
03:20the formation of stars and clusters by revealing the physics underlying the structures they leave behind
03:27the x arithmetic technique brings us closer to understanding the influence of black holes on the largest scales
03:36so
03:37so
03:40so
03:40i
03:53Transcription by CastingWords
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