Alar Toomre#Scientific accomplishments

Following the Soviet occupation of Estonia in 1944, Toomre and his family fled to Germany; they emigrated to the United States in 1949. He received an undergraduate degree in Aeronautical Engineering and Physics from MIT in 1957{{cite news|url = http://tech.mit.edu/archives/VOL_076/TECH_V076_S0031_P006.pdf|title = Dormcon Prexy Vote Thursday Joe Bowers '57 Only Candidate|newspaper = The Tech|date = February 26, 1956|page = 6|access-date = 2007-05-18|archive-date = 2016-03-04|archive-url = https://web.archive.org/web/20160304111343/http://tech.mit.edu/archives/VOL_076/TECH_V076_S0031_P006.pdf|url-status = dead}} and then studied at the University of Manchester on a Marshall Scholarship where he obtained a Ph.D. in fluid mechanics.{{cite news|url = http://tech.mit.edu/archives/VOL_077/TECH_V077_S0116_P006.pdf|title = Alar Toomre, Course XVI Senior, To Receive Marshall Scholarship|date = April 9, 1957|page = 6|access-date = 2007-05-18|archive-date = 2016-03-03|archive-url = https://web.archive.org/web/20160303170114/http://tech.mit.edu/archives/VOL_077/TECH_V077_S0116_P006.pdf|url-status = dead}}{{cite news|url = http://tech.mit.edu/archives/VOL_104/TECH_V104_S0817_P012.pdf|title = Toomre Receives MacArthur Award|newspaper = The Tech|date = November 16, 1984|page = 22|access-date = 2007-05-18|archive-date = 2016-03-03|archive-url = https://web.archive.org/web/20160303211959/http://tech.mit.edu/archives/VOL_104/TECH_V104_S0817_P012.pdf|url-status = dead}}

Toomre returned to MIT to teach after completing his Ph.D. and remained there for two years. After spending a year at the Institute for Advanced Study, he returned again to MIT as part of the faculty, where he stayed. Toomre was appointed an Associate Professor of Mathematics at MIT in 1965, and Professor in 1970.{{cite web | url = http://math.mit.edu/people/profile?pid=277 | title = MIT Faculty Home page. | access-date = 2011-01-16 | archive-date = 2013-01-23 | archive-url = https://web.archive.org/web/20130123174401/http://math.mit.edu/people/profile?pid=277 | url-status = dead }}

Image:ToomreandToomreF23.png

In 1964, Toomre devised a local gravitational stability criterion for differentially rotating disks.{{cite web|url=http://www.hpcwire.com/hpc/853956.html |title=Star Maker Machinery |author=Tim Palucka |publisher=HPC wire |access-date=2007-05-18 |url-status=dead |archive-url=https://web.archive.org/web/20070928004206/http://www.hpcwire.com/hpc/853956.html |archive-date=2007-09-28 }} It is known as the Toomre stability criterion, which is usually measured by a parameter denoted as Q.{{cite book|author = James Binney|author-link = James Binney|author2 = Scott Tremaine|author2-link = Scott Tremaine|name-list-style = amp|title = Galactic Dynamics|page = 363|publisher = Princeton University Press|editor = Jeremiah Ostriker|editor-link = Jeremiah Ostriker|date = 1994|location = Princeton, New Jersey|isbn = 0-691-08445-9|orig-year = 1987}} The Q parameter measures the relative

importance of vorticity and internal velocity dispersion (large values of which stabilise) versus the disk surface density (large values of which destabilise). The parameter is constructed so that Q<1 implies instability.

Toomre collaborated with Peter Goldreich in 1969 on the subject of polar wander, developing the theory of polar wander.{{cite journal|title = Did the Dinosaurs Live on a Topsy-Turvy Earth?|author = Richard A. Kerr|journal = Science|date = January 21, 2000|pages = 406–407|volume = 287|doi = 10.1126/science.287.5452.406|issue = 5452|s2cid = 129200632}} Whether true polar wander has been observed on earth, or apparent polar wander is accountable for all the observations of paleomagnetism remains a controversial issue.{{cite journal|bibcode = 2004AGUFM.U31B..08C|title = A Short Review of True Polar Wander|author = V. Courtillot |date = Fall 2004|volume = 31|pages = U31B–08|journal = AGU Fall Meeting Abstracts}} abstract #U31B-08

Image:NGC40384039 large.jpg]]

Toomre conducted the first computer simulations of galaxy mergers in the 1970s with his brother Jüri, an astrophysicist and solar physicist.{{cite journal|url = http://scicom.ucsc.edu/SciNotes/9701/full/features/galaxy/Toomre.html|title = Toomre and the first models|journal = Science Notes University of Santa Cruz|date = Summer 1997|access-date = 2007-05-18}}{{cite magazine|url = http://findarticles.com/p/articles/mi_m1200/is_n14_v135/ai_7535883|title = Mixing it up in space: astronomers debate the role mergers play in galaxy formation|author = Karen Hartley|magazine = Science News|date = April 8, 1989|access-date = 2007-05-18}} Although the small number of particles in the simulations obscured many processes in galactic collisions, Toomre and Toomre were able to identify tidal tails in his simulations, similar to those seen in the Antennae Galaxies and the Mice.{{cite web|url = http://hubblesite.org/newscenter/archive/releases/1997/34/astrofile/|title = Hubble Reveals Stellar Fireworks Accompanying Galaxy Collisions|date = October 21, 1997|publisher = Space Telescope Science Institute|access-date = 2007-05-18| archive-url= https://web.archive.org/web/20070420221652/http://hubblesite.org/newscenter/archive/releases/1997/34/astrofile/| archive-date= 20 April 2007 | url-status= live}}{{cite web|url = http://www.spaceref.com/news/viewpr.html?pid=8197|archive-url = https://archive.today/20120915084739/http://www.spaceref.com/news/viewpr.html?pid=8197|url-status = dead|archive-date = September 15, 2012|title = The Mice at Play|publisher = National Radio Astronomy Observatory|date = May 1, 2002}}{{cite web|url = http://findarticles.com/p/articles/mi_m1134/is_1_109/ai_59210822/pg_2|title = Cannibals of the Cosmos - much more has become known about galaxies, since Edwin Hubble confirmed their existence in 1925|publisher = Natural History|author = Michael Shara|date = February 2000|access-date = 2007-05-18|archive-date = 2011-06-16|archive-url = https://web.archive.org/web/20110616023012/http://findarticles.com/p/articles/mi_m1134/is_1_109/ai_59210822/pg_2/|url-status = dead}} The brothers attempted to reproduce specific galaxy mergers in their simulations, and it was their reproduction of the Antennae galaxies that gave them the greatest pleasure.{{cite journal|bibcode = 1972ApJ...178..623T|title = Galactic Tails and Bridges|author = Alar Toomre|author2 = Jüri Toomre|author2-link = |name-list-style = amp|journal = The Astrophysical Journal|date = 1972|pages = 623–666|volume = 178|doi = 10.1086/151823}} In 1977 Toomre suggested that elliptical galaxies are the remnants of the major mergers of spiral galaxies.{{cite web|url = http://burro.astr.cwru.edu/JavaLab/GalCrashWeb/ellipt.html|title = Merger Remnants and Elliptical Galaxies|access-date = 2007-05-18|archive-url = https://web.archive.org/web/20070711041838/http://burro.astr.cwru.edu/JavaLab/GalCrashWeb/ellipt.html|archive-date = 2007-07-11|url-status = dead}}{{cite web|url = http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=39833|title = Peering Far Back in Time to Uncover the Secrets of Galaxy Evolution|publisher = European Space Agency|date = December 1, 1992|access-date = 2007-05-18}} He further showed that based on the local galaxy merger rate, over a Hubble time the observed number of elliptical galaxies are produced if the universe begins with only spiral galaxies.{{cite web|url = http://www.casca.ca/ecass/issues/1997-DS/West/west-bil.html|title = THE GALAXY-CLUSTER-SUPERCLUSTER CONNECTION|author = Michael J. West|publisher = Canadian Astronomical Society/Société Canadienne D'Astronomie Cassiopeia|number = 95|date = December 1997}} This idea remained controversial and widely debated for some time.{{cite web|url = http://www2.ifa.hawaii.edu/newsletters/article.cfm?a=187&n=18|title = Merging Spiral Galaxies Create Ellipticals|author = Robert Joseph|publisher = Nã Kilo Hõkũ|number = 13|date = Fall 2004|access-date = 2007-05-18}}{{cite journal|arxiv = astro-ph/9908269|title = Galaxy Collisions|author = Curtis Struck|date = 1999|volume = 321|issue = 1–3|pages = 1–137|bibcode = 1999PhR...321....1S |doi = 10.1016/S0370-1573(99)00030-7|journal = Physics Reports |s2cid = 119369136}}

From this work, the Toomre brothers identified the process of collision evolution as the Toomre sequence.{{cite web|url = http://cosmos.swin.edu.au/entries/toomresequence/toomresequence.html?e=1|title = Toomre Sequence|publisher = Cosmos: The Swinburne Astronomy Online Encyclopedia|access-date = 2007-05-18}}{{cite journal|bibcode = 2001ASPC..249..179L|title = HST Observations of the Nuclear Regions of the Toomre Sequence of Merging Galaxies|author = Laine, S.|author2 = van der Marel, R. P.|author3 = Böker, T.|author4 = Mihos, J. C.|author5 = Hibbard, J. E.|author6 = Zabludoff, A. I.|author6-link= Ann Zabludoff |journal= ASP Conference Proceedings|volume = 249|isbn = 1-58381-089-7|date = 2000|pages = 179|arxiv = astro-ph/0106396}} The sequence begins with two well separated spiral galaxies and follows them (as for the Antennae) through collisional disruption until they settle into a single elliptical galaxy.{{cite journal|url=http://www.aanda.org/index.php?option=com_base_ora&url=articles/aa/full/2001/10/aa10295/aa10295.html&access=standard&Itemid=81 |title=HI line observations of luminous infrared galaxy mergers |author=W. van Driel - Yu Gao - D. Monnier-Ragaigne |journal=Astronomy and Astrophysics |date=2001 |volume=368 |issue=1 |pages=64–73 |access-date=2007-05-18 |doi=10.1051/0004-6361:20000509 |archive-url=https://web.archive.org/web/20070927194211/http://www.aanda.org/index.php?option=com_base_ora&url=articles%2Faa%2Ffull%2F2001%2F10%2Faa10295%2Faa10295.html&access=standard&Itemid=81 |archive-date=2007-09-27 |bibcode=2001A&A...368...64V |arxiv=astro-ph/0101003 |s2cid=7784821 |url-status=live }}

In 1993, Toomre received the Dirk Brouwer Award which recognizes "outstanding contributions to the field of Dynamical Astronomy".{{cite web|url = https://dda.harvard.edu/newsletters/ddanews75.html|title = AAS Division on Dynamical Astronomy Newsletter 75|date = October 1993|access-date = 2007-05-18|publisher = American Astronomical Society Division on Dynamical Astronomy| archive-url= https://web.archive.org/web/20070702120414/http://dda.harvard.edu/newsletters/ddanews75.html| archive-date= 2 July 2007 | url-status= live}}{{cite web|url = http://dda.harvard.edu/brouwer_award/index.html|title = The DDA/AAS Brouwer Award|publisher = American Astronomical Society/Division on Dynamical Astronomy|access-date = 2007-05-18| archive-url= https://web.archive.org/web/20070513012548/http://dda.harvard.edu/brouwer_award/index.html| archive-date= 13 May 2007 | url-status= live}}

Toomre was one of the 1984 recipients of the MacArthur Fellowship, popularly known as the "Genius Grant".{{cite web|url = http://web.mit.edu/newsoffice/2004/macarthurs.html|title = MacArthur 'genius' grants go to four from MIT|author = Elizabeth A. Thomson|date = September 28, 2004|publisher = MIT news office|access-date = 2007-05-18|archive-date = 2013-09-28|archive-url = https://web.archive.org/web/20130928034035/http://web.mit.edu/newsoffice/2004/macarthurs.html|url-status = dead}}

In 1985, Toomre was elected a Fellow of the American Association for the Advancement of Science (AAAS).{{cite web|title=Historic Fellows Listing|website=American Association for the Advancement of Science (aaas.org)|url=https://www.aaas.org/fellows/historic}} (search on last_name="Toomre")

Toomre was the recipient of the Magellanic Premium award in 2014 for his work in numerical galaxy simulations during the 1960s.{{cite web|url = https://amphilsoc.org/prizes/presentations/2014/Autumn-General-Meeting/Magellanic-Premium|title = 2014 Autumn General Meeting|date = 2014|access-date = 2017-04-05|archive-url = https://web.archive.org/web/20170213210403/https://amphilsoc.org/prizes/presentations/2014/Autumn-General-Meeting/Magellanic-Premium|archive-date = 2017-02-13|url-status = dead}} Two years later, he was elected to the American Philosophical Society.{{Cite web|title=APS Member History|url=https://search.amphilsoc.org/memhist/search?creator=Alar+Toomre&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced|access-date=2021-02-18|website=search.amphilsoc.org}}

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Category:1937 births

Category:Living people

Category:American astronomers

Category:20th-century American mathematicians

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Category:Massachusetts Institute of Technology School of Science alumni

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Category:MacArthur Fellows

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Category:Estonian emigrants to the United States

Category:Estonian World War II refugees

Category:People from Rakvere

Category:Marshall Scholars