Kara delik denilince \u00e7o\u011fu ki\u015finin akl\u0131na, yeterince yak\u0131n\u0131ndan ge\u00e7en her \u015feyi yutan devasa bir vakum makinesi gelir. Fakat galaksilerin merkezinde bulunan s\u00fcper k\u00fctleli kara delikler, daha \u00e7ok i\u00e7lerine d\u00fc\u015fen maddenin enerjisini \u0131\u015f\u0131maya d\u00f6n\u00fc\u015ft\u00fcren kozmik motorlar\u0131 and\u0131r\u0131r. Bu t\u00fcr kara deliklerin yapt\u0131\u011f\u0131 \u0131\u015f\u0131ma, \u00e7evresindeki y\u0131ld\u0131zlar\u0131n yayd\u0131\u011f\u0131 toplam \u0131\u015f\u0131\u011f\u0131 g\u00f6lgede b\u0131rakacak \u00f6l\u00e7\u00fcde fazlad\u0131r. Kendi etraf\u0131nda d\u00f6nen kara delikler binlerce \u0131\u015f\u0131k y\u0131l\u0131 mesafelere eri\u015fen g\u00fc\u00e7l\u00fc jetler \u00fcretir. Bug\u00fcne kadar yap\u0131lan teorik \u00e7al\u0131\u015fmalar bu t\u00fcr kara delik motorlar\u0131n\u0131n manyetik alanlar taraf\u0131ndan beslendi\u011fini \u00f6ng\u00f6r\u00fcyordu. Astronomlar ilk kez, galaksimizin merkezinde bulunan kara deli\u011fin olay ufkunun hemen d\u0131\u015f\u0131ndaki manyetik alan\u0131 tespit etmeyi ba\u015fard\u0131.<\/p>\n
Bu ay\u0131n ba\u015f\u0131nda yay\u0131mlanan makalenin ba\u015fyazar\u0131 Harvard-Smithsonian Astrofizik Merkezi\u2019nden (CfA) Michael Johnson konuyla ilgili olarak \u201cBu manyetik alanlar\u0131 anlamak kritik \u00f6neme sahip. \u015eimdiye kadar hi\u00e7 kimse olay ufku yak\u0131nlar\u0131ndaki manyetik alanlar\u0131 tespit etmeyi ba\u015faramam\u0131\u015ft\u0131\u201d diyor. \u00c7al\u0131\u015fman\u0131n sonu\u00e7lar\u0131 4 Aral\u0131k\u2019da Science<\/em> dergisinde yay\u0131mland\u0131.<\/p>\n Ba\u015f ara\u015ft\u0131rmac\u0131 ve MIT\u2019e ait Haystack G\u00f6zlemevi\u2019nin yard\u0131mc\u0131 y\u00f6neticisi Shep Doeleman, \u201cBu manyetik alanlar\u0131n varl\u0131\u011f\u0131 (teorik olarak) \u00f6ng\u00f6r\u00fclm\u00fc\u015ft\u00fc, fakat daha \u00f6nce kimse bunlar\u0131 g\u00f6zlemlemeyi ba\u015faramad\u0131. Elde etti\u011fimiz veriler on y\u0131llard\u0131r ger\u00e7ekle\u015ftirilen teorik \u00e7al\u0131\u015fmalar\u0131 sa\u011flam bir g\u00f6zlemsel temele oturttu\u201d diyor.<\/p>\n \u00c7al\u0131\u015fmada Olay Ufku Teleskopu\u2019yla (EHT) elde edilen veriler kullan\u0131ld\u0131. Birbirleriyle e\u015fg\u00fcd\u00fcml\u00fc olarak \u00e7al\u0131\u015fan k\u00fcresel bir radyo teleskop a\u011f\u0131 olan EHT, bu haliyle 15 mikro yay-saniye hassasiyete sahip, D\u00fcnya boyutlar\u0131nda dev bir teleskop gibi d\u00fc\u015f\u00fcn\u00fclebilir (1 yay-saniye bir derecenin 1\/3600\u2019\u00fcne kar\u015f\u0131l\u0131k gelir ve 15 mikro yay-saniye hassasiyet demek, Ay y\u00fczeyindeki bir golf topunu g\u00f6rebilmeye e\u015fde\u011ferdir).<\/p>\n Kara delikler evrendeki en yo\u011fun cisimler oldu\u011fundan bu \u00f6l\u00e7\u00fcde hassas \u00f6l\u00e7\u00fcm yapabilmek \u015fart. Samanyolu\u2019nun merkezinde bulunan Sagittarius A (Sgr A*) 4 milyon G\u00fcne\u015f k\u00fctlesine sahip olmas\u0131na ra\u011fmen, olay uykunun geni\u015fli\u011fi sadece 8 milyon mil; yani Merk\u00fcr\u2019\u00fcn y\u00f6r\u00fcngesinden daha k\u00fc\u00e7\u00fck. Sgr A*\u2019\u0131n 25.000 \u0131\u015f\u0131k y\u0131l\u0131 uza\u011f\u0131m\u0131zda bulundu\u011funu hesaba katt\u0131\u011f\u0131m\u0131zda bu durum, olay ufkunun boyutlar\u0131n\u0131n sadece 10 mikro yay-saniyeye kar\u015f\u0131l\u0131k geldi\u011fi anlam\u0131na geliyor; yani inan\u0131lmaz derecede k\u00fc\u00e7\u00fck. Neyse ki, kara deli\u011fin yo\u011fun k\u00fctle\u00e7ekimi \u0131\u015f\u0131\u011f\u0131 b\u00fckerek mercek etkisi yarat\u0131yor ve bu sayede g\u00f6ky\u00fcz\u00fcnde daha b\u00fcy\u00fck g\u00f6r\u00fcnmesini sa\u011fl\u0131yor. Yakla\u015f\u0131k 50 mikro yay-saniye geni\u015fli\u011findeki bu de\u011fer, EHT\u2019nin rahatl\u0131kla ay\u0131rt edebilece\u011fi d\u00fczeyde.<\/p>\n \u00c7al\u0131\u015fmay\u0131 ger\u00e7ekle\u015ftiren ekip, EHT\u2019nin 1,3 mm\u2019lik dalga boyunda elde edilen g\u00f6zlem verilerini kullanarak \u0131\u015f\u0131\u011f\u0131n do\u011frusal polarizasyonunu \u00f6l\u00e7t\u00fc. G\u00fcne\u015f \u0131\u015f\u0131\u011f\u0131, D\u00fcnya atmosferinde yans\u0131ma nedeniyle do\u011frusal olarak polarize olur (Ayn\u0131 mant\u0131kla \u0131\u015f\u0131\u011f\u0131 engellemek ve parlamay\u0131 d\u00fc\u015f\u00fcrmek i\u00e7in g\u00fcne\u015f g\u00f6zl\u00fckleri de polarizedir). Sgr A*\u2019\u0131n durumunda ise polarize olmu\u015f \u0131\u015f\u0131k, manyetik alan \u00e7izgileri etraf\u0131nda spiral \u00e7izen elektronlar taraf\u0131ndan yay\u0131nlan\u0131r. Bunun sonucunda \u0131\u015f\u0131k direkt olarak manyetik alan\u0131 takip eder.<\/p>\n Yak\u0131n\u0131ndaki maddelerin olu\u015fturdu\u011fu bir y\u0131\u011f\u0131lma diskiyle \u00e7evrili olan Sgr A*\u2019\u0131 g\u00f6zlemleyen ekip, kara deli\u011fe yak\u0131n baz\u0131 b\u00f6lgedeki manyetik alanlar\u0131n i\u00e7 i\u00e7e ge\u00e7mi\u015f bir spagettiyi and\u0131racak \u015fekilde sarmallardan ve kar\u0131\u015f\u0131k \u00e7evrimlerden meydana gelen bir d\u00fczensizlik i\u00e7erisinde oldu\u011funu ke\u015ffetti. Di\u011fer b\u00f6lgelerin ise, bunun aksine, \u00e7ok daha d\u00fczenli bir motife sahip oldu\u011fu g\u00f6r\u00fcnd\u00fc. Bu b\u00f6lgeler b\u00fcy\u00fck ihtimalle jetlerin ger\u00e7ekle\u015fti\u011fi k\u0131s\u0131mlar.<\/p>\n Di\u011fer bir bulgu ise manyetik alan\u0131n 15 dakika gibi k\u0131sa bir zaman \u00f6l\u00e7e\u011finde, dalgalanmalar g\u00f6sterdi\u011fi.<\/p>\n Johnson bu konuda \u201cGalaksimizin merkezi, bir kez daha tahmin etti\u011fimizden daha dinamik bir yer oldu\u011funu bize g\u00f6sterdi. Bu manyetik alanlar her yerde dans ediyor\u201d diyor.<\/p>\n G\u00f6zlemler yap\u0131l\u0131rken 3 farkl\u0131 co\u011frafik b\u00f6lgede bulunan astronomi kurulu\u015fundan yararlan\u0131ld\u0131: \u0130kisi de Hawaii – Mauna Kea\u2019 da bulunan SMA (Submillimeter Array) ve James Clerk Maxwell Teleskopu, Arizona – Mt. Graham\u2019da bulunan SMT (Submillimeter Telescope) ve Kaliforniya \u2013 Bishop\u2019ta bulunan CARMA (Combined Array for Research in Millimeter-wave Astronomy). EHT\u2019nin D\u00fcnya \u00e7ap\u0131ndaki radyo \u00e7ana\u011f\u0131 say\u0131s\u0131 artt\u0131r\u0131larak bir kara deli\u011fin olay ufkunu direkt olarak g\u00f6r\u00fcnt\u00fcleme olana\u011f\u0131n\u0131 sa\u011flayacak \u00e7\u00f6z\u00fcn\u00fcrl\u00fck de\u011ferlerine ula\u015ft\u0131r\u0131lmas\u0131 hedefleniyor.<\/p>\n Doeleman bununla ilgili olarak \u201cD\u00fcnya ebatlar\u0131na yay\u0131lm\u0131\u015f bir teleskopun in\u015fas\u0131 i\u00e7in tek yol biliminsanlar\u0131n\u0131n k\u00fcresel olarak birlikte \u00e7al\u0131\u015fmas\u0131ndan ge\u00e7iyor. Elde edilen bu bilimsel sonu\u00e7larla birlikte EHT ekibi, astronominin merkezi bir paradoksunu \u00e7\u00f6zmeye bir ad\u0131m daha yakla\u015fm\u0131\u015ft\u0131r: Neden kara delikler \u00e7ok parlak?\u201d diye ekliyor.<\/p>\n","protected":false},"excerpt":{"rendered":" Kara delik denilince \u00e7o\u011fu ki\u015finin akl\u0131na, yeterince yak\u0131n\u0131ndan ge\u00e7en her \u015feyi yutan devasa bir vakum makinesi gelir. Fakat galaksilerin merkezinde bulunan s\u00fcper k\u00fctleli kara delikler, daha \u00e7ok i\u00e7lerine d\u00fc\u015fen maddenin enerjisini \u0131\u015f\u0131maya d\u00f6n\u00fc\u015ft\u00fcren kozmik motorlar\u0131 and\u0131r\u0131r. Bu t\u00fcr kara deliklerin yapt\u0131\u011f\u0131 \u0131\u015f\u0131ma, \u00e7evresindeki y\u0131ld\u0131zlar\u0131n yayd\u0131\u011f\u0131 toplam \u0131\u015f\u0131\u011f\u0131 g\u00f6lgede b\u0131rakacak \u00f6l\u00e7\u00fcde fazlad\u0131r. Kendi etraf\u0131nda d\u00f6nen kara […]<\/p>\n","protected":false},"author":677,"featured_media":16430,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[180,30,19,26],"tags":[248,657,1651,766,993],"class_list":["post-4383","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-143-sayi","category-astronomi","category-bilim-gundemi","category-fizik","tag-astronomi","tag-evren","tag-galaksi","tag-kara-delik","tag-manyetik-alan"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t