The warm–hot intergalactic medium (WHIM) is the sparse, warm-to-hot (105 to 107K) plasma that cosmologists believe to exist in the spaces between galaxies and to contain 40–50%[1][2] of the baryonic 'normal matter' in the universe at the current epoch.[3] The WHIM can be described as a web of hot, diffuse gas stretching between galaxies, and consists of plasma, as well as atoms and molecules, in contrast to dark matter. The WHIM is a proposed solution to the missing baryon problem, where the observed amount of baryonic matter does not match theoretical predictions from cosmology.[4]
Computer simulation showing the distribution of warm-hot intergalactic gas
Much of what is known about the warm–hot intergalactic medium comes from computer simulations of the cosmos.[5] The WHIM is expected to form a filamentary structure of tenuous, highly ionized baryons with a density of 1−10 particles per cubic meter.[6] Within the WHIM, gas shocks are created as a result of active galactic nuclei, along with the gravitationally-driven processes of merging and accretion. Part of the gravitational energy supplied by these effects is converted into thermal emissions of the matter by collisionlessshock heating.[1]
Because of the high temperature of the medium, the expectation is that it is most easily observed from the absorption or emission of ultraviolet and low energy X-ray radiation. To locate the WHIM, researchers examined X-ray observations of a rapidly growing supermassive black hole known as an active galactic nucleus, or AGN. Oxygen atoms in the WHIM were seen to absorb X-rays passing through the medium.[7] In May 2010, a giant reservoir of WHIM was detected by the Chandra X-ray Observatory lying along the wall-shaped structure of galaxies (Sculptor Wall) some 400 million light-years from Earth.[7][8] In 2018, observations of highly-ionized extragalactic oxygen atoms appeared to confirm simulations of the WHIM mass distribution.[4] Observations for dispersion from fast radio bursts in 2020, further appeared to confirm the missing baryonic mass to be located at the WHIM.[9]
Circumgalactic mediumedit
Conceptually similar to WHIM, circumgalactic medium (CGM) is a halo of gas surrounding galaxies that is diffuse, and nearly invisible. Current thinking is that the CGM is an important source of star-forming material, and that it regulates a galaxy’s gas supply. If visible, the CGM of the Andromeda Galaxy (1.3-2 million ly) would stretch 3 times the size of the width of the Big Dipper—easily the biggest feature on the nighttime sky, and even bump into our own CGM, though that isn't fully known because we reside in it. There are two layered parts to Andromeda CGM: an inner shell of gas is nested inside an outer shell. The inner shell (0.5 million ly) is more dynamic and is thought to be more dynamic and turbulent because of outflows from supernova, and the outer shell is hotter and smoother.[10]
See alsoedit
Look up warm-hot intergalactic medium in Wiktionary, the free dictionary.
^ abBykov, A. M.; et al. (February 2008), "Equilibration Processes in the Warm-Hot Intergalactic Medium", Space Science Reviews, 134 (1–4): 141–153, arXiv:0801.1008, Bibcode:2008SSRv..134..141B, doi:10.1007/s11214-008-9309-4, S2CID 17801881.
^Moskvitch, Katia (16 September 2018). "Astronomers Have Found The Universe's Missing Matter - For decades, some of the atomic matter in the universe had not been located. Recent papers reveal where it's been hiding". Wired. Retrieved 16 September 2018.
^Reimers, D. (2002), "Baryons in the diffuse intergalactic medium", Space Science Reviews, 100 (1/4): 89, Bibcode:2002SSRv..100...89R, doi:10.1023/A:1015861926654, S2CID 122465345
^ abNicastro, F.; et al. (June 2018), "Observations of the missing baryons in the warm-hot intergalactic medium", Nature, 558 (7710): 406–409, arXiv:1806.08395, Bibcode:2018Natur.558..406N, doi:10.1038/s41586-018-0204-1, PMID 29925969, S2CID 49347964.
^Ryden, Barbara; Pogge, Richard (June 2016), Interstellar and Intergalactic Medium, Ohio State Graduate Astrophysics Series, The Ohio State University, pp. 240−244, ISBN978-1-914602-02-7{{citation}}: CS1 maint: ignored ISBN errors (link)
^Nicastro, Fabrizio; et al. (January 2008). "Missing Baryons and the Warm-Hot Intergalactic Medium". Science. 319 (5859): 55–57. arXiv:0712.2375. Bibcode:2008Sci...319...55N. doi:10.1126/science.1151400. PMID 18174432. S2CID 10622539.
^"Last "Missing" Normal Matter Is Found - Sky & Telescope". 14 May 2010.
^Macquart, J.-P.; et al. (May 2020), "A census of baryons in the Universe from localized fast radio bursts", Nature, 581 (7809): 391–395, arXiv:2005.13161, Bibcode:2020Natur.581..391M, doi:10.1038/s41586-020-2300-2, PMID 32461651, S2CID 218900828.
^"Hubble Shows the True Size of Andromeda". September 2020.
May 07, 2024
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The warm hot intergalactic medium WHIM is the sparse warm to hot 105 to 107 K plasma that cosmologists believe to exist in the spaces between galaxies and to contain 40 50 1 2 of the baryonic normal matter in the universe at the current epoch 3 The WHIM can be described as a web of hot diffuse gas stretching between galaxies and consists of plasma as well as atoms and molecules in contrast to dark matter The WHIM is a proposed solution to the missing baryon problem where the observed amount of baryonic matter does not match theoretical predictions from cosmology 4 Computer simulation showing the distribution of warm hot intergalactic gas Much of what is known about the warm hot intergalactic medium comes from computer simulations of the cosmos 5 The WHIM is expected to form a filamentary structure of tenuous highly ionized baryons with a density of 1 10 particles per cubic meter 6 Within the WHIM gas shocks are created as a result of active galactic nuclei along with the gravitationally driven processes of merging and accretion Part of the gravitational energy supplied by these effects is converted into thermal emissions of the matter by collisionless shock heating 1 Because of the high temperature of the medium the expectation is that it is most easily observed from the absorption or emission of ultraviolet and low energy X ray radiation To locate the WHIM researchers examined X ray observations of a rapidly growing supermassive black hole known as an active galactic nucleus or AGN Oxygen atoms in the WHIM were seen to absorb X rays passing through the medium 7 In May 2010 a giant reservoir of WHIM was detected by the Chandra X ray Observatory lying along the wall shaped structure of galaxies Sculptor Wall some 400 million light years from Earth 7 8 In 2018 observations of highly ionized extragalactic oxygen atoms appeared to confirm simulations of the WHIM mass distribution 4 Observations for dispersion from fast radio bursts in 2020 further appeared to confirm the missing baryonic mass to be located at the WHIM 9 Circumgalactic medium editConceptually similar to WHIM circumgalactic medium CGM is a halo of gas surrounding galaxies that is diffuse and nearly invisible Current thinking is that the CGM is an important source of star forming material and that it regulates a galaxy s gas supply If visible the CGM of the Andromeda Galaxy 1 3 2 million ly would stretch 3 times the size of the width of the Big Dipper easily the biggest feature on the nighttime sky and even bump into our own CGM though that isn t fully known because we reside in it There are two layered parts to Andromeda CGM an inner shell of gas is nested inside an outer shell The inner shell 0 5 million ly is more dynamic and is thought to be more dynamic and turbulent because of outflows from supernova and the outer shell is hotter and smoother 10 See also edit nbsp Look up warm hot intergalactic medium in Wiktionary the free dictionary Intergalactic space Intracluster mediumReferences edit a b Bykov A M et al February 2008 Equilibration Processes in the Warm Hot Intergalactic Medium Space Science Reviews 134 1 4 141 153 arXiv 0801 1008 Bibcode 2008SSRv 134 141B doi 10 1007 s11214 008 9309 4 S2CID 17801881 Moskvitch Katia 16 September 2018 Astronomers Have Found The Universe s Missing Matter For decades some of the atomic matter in the universe had not been located Recent papers reveal where it s been hiding Wired Retrieved 16 September 2018 Reimers D 2002 Baryons in the diffuse intergalactic medium Space Science Reviews 100 1 4 89 Bibcode 2002SSRv 100 89R doi 10 1023 A 1015861926654 S2CID 122465345 a b Nicastro F et al June 2018 Observations of the missing baryons in the warm hot intergalactic medium Nature 558 7710 406 409 arXiv 1806 08395 Bibcode 2018Natur 558 406N doi 10 1038 s41586 018 0204 1 PMID 29925969 S2CID 49347964 Ryden Barbara Pogge Richard June 2016 Interstellar and Intergalactic Medium Ohio State Graduate Astrophysics Series The Ohio State University pp 240 244 ISBN 978 1 914602 02 7 a href Template Citation html title Template Citation citation a CS1 maint ignored ISBN errors link Nicastro Fabrizio et al January 2008 Missing Baryons and the Warm Hot Intergalactic Medium Science 319 5859 55 57 arXiv 0712 2375 Bibcode 2008Sci 319 55N doi 10 1126 science 1151400 PMID 18174432 S2CID 10622539 a b Huge Chunk of Universe s Missing Matter Found Space com Retrieved 2016 12 05 Last Missing Normal Matter Is Found Sky amp Telescope 14 May 2010 Macquart J P et al May 2020 A census of baryons in the Universe from localized fast radio bursts Nature 581 7809 391 395 arXiv 2005 13161 Bibcode 2020Natur 581 391M doi 10 1038 s41586 020 2300 2 PMID 32461651 S2CID 218900828 Hubble Shows the True Size of Andromeda September 2020 Retrieved from https en wikipedia org w index php title Warm hot intergalactic medium amp oldid 1182223744, wikipedia, wiki, book, books, library,
