Free Astronomy Magazine November-December 2024 ARABIC VERSION

Q Early-Universe quasar neighborhoods are indeed cluttered byNOIRLab − JosieFenske uasars are the most lumi- nous objects in the Universe andarepoweredbymate- rial accreting onto supermassive blackholesatthecentersofgalax- ies. Studies have shown that early- Universe quasars have black holes so massive that they must have been swallowing gas at very high rates, leadingmostastronomerstobelieve that these quasars formed in some of the densest environments in the Universewheregaswasmostavail- able.However,observationalmea- surements seeking to confirm this conclusionhavethusfaryielded conflictingresults.Now,anew studyusingtheDarkEnergyCamera (DECam) points the way to both an explanationforthesedisparateob- servationsandalsoalogicalframe- work to connect observation with theory.DECamwasfabricatedby theDepartmentofEnergyandis mounted on the U.S. National Sci- ence Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF NOIRLab. The study was led by Trystan Lam- bert,whocompletedthisworkasa PhDstudentatDiegoPortalesUni- versity’s Institute of Astrophysical Studies in Chile and is now a post- doc at the University of Western Australia node at the International Centre for Radio Astronomy Re- search (ICRAR). Utilizing DECam’s massivefieldofview,theteamcon- ducted the largest on-sky area search ever around an early-Uni- versequasarinanefforttomeasure the density of its environment by counting the number of surround- ing companion galaxies. For their investigation, the team needed a quasar with a well-de- fineddistance.Luckily,quasarVIK ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 36 إ زدﺣﺎمﻣﻨﺎﻃﻖ اﻟ ﻮازار ات ﻓﻲوﻗﺖﻣ ﻜﺮﻣﻦ اﻟ ﻮن : ﻘﻠﻢ ﺟﻮزيﻓ ﻨﺴﻜﻲ – ﻣﺨﺘ ﻧﻮﻳﺮﻻب ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4 إن اﻟﻜﻮازارات ﻫﻲ أﻛﺜﺮ اﻷﺟﺴﺎم إﴍاﻗﺎً ﰲ اﻟﻜﻮن وﻫﻲ ﺗ ﻨﺸﻂ ﺑﻔﻀﻞ ا ﻮاد ا ﱰ اﻛﻤـﺔ ﻋﲆ اﻟﺜﻘﻮب اﻟﺴﻮداء ﻓﺎﺋﻘﺔ اﻟﻜﺘﻠﺔ ﰲ ﻣﺮاﻛﺰ ا ﺠﺮات وﻗﺪ أﻇﻬﺮ اﻟﻌﺪﻳﺪ ﻣﻦ اﻟﺪراﺳﺎت أن اﻟﻜﻮازارات ﰲ وﻗﺖ ﻣﺒﻜﺮ ﻣﻦ ﺗﺎرﻳﺦ اﻟﻜـﻮن ﺗﺤﺘﻮي ﻋﲆ ﺛﻘﻮب ﺳﻮداء ﺿـﺨﻤﺔ ﻟﺪرﺟـﺔ أﻧﻬﺎ ﻻﺑﺪ وأن ﺗﻜـﻮن ﻗـﺪ اﺑﺘﻠﻌـﺖ اﻟﻐـﺎز ات ﺑﻤﻌﺪﻻت ﻋﺎﻟﻴﺔ ﻟﻠﻐﺎﻳـﺔ ﻣﻤـﺎ دﻓـﻊ ﻣﻌﻈـﻢ ﻋﻠﻤــﺎء اﻟﻔﻠــﻚ إﱃ اﻻﻋﺘﻘــﺎد ﺑــﺄن ﻫــﺬه اﻟﻜـﻮازارات ﺗﺸــﻜﻠﺖ ﰲ ﺑﻌـﺾ ﻣـﻦ أﻛﺜـﺮ اﻟﺒﻴﺌﺎت ﻛﺜﺎﻓﺔ ﰲ اﻟﻜﻮن ﺣ ﻴـﺚ ﻛـﺎن اﻟﻐـﺎز ﻣﺘﺎﺣﺎً ﺑﺸﻜﻞ ﻛﺒ وﻣﻊ ذﻟﻚ ﻓﺈن اﻟﻘﻴﺎﺳﺎت اﻟﺮﺻــﺪﻳﺔ اﻟﺘــﻲ ﺗﺴــﻌﻰ إﱃ ﺗﺄﻛﻴــﺪ ﻫــﺬا اﻻﺳﺘﻨﺘﺎج ﻗﺪ أﺳﻔﺮت ﻋﻦ ﻧﺘﺎﺋﺞ ﻣﺘﻀﺎرﺑﺔ . اﻵن ﺗﺸ دراﺳﺔ ﺟﺪﻳﺪة ﺑﺎﺳﺘﺨﺪام ﻛـﺎﻣ ا اﻟﻄﺎﻗﺔ ا ﻈﻠﻤﺔ ) دي ﻛـﺎم ( إﱃ اﻟﻄﺮﻳـﻖ إﱃ ﺗﻔﺴـ ﻟﻬـﺬه اﻻرﺻـﺎد ا ﺘﺒﺎﻳﻨـﺔ وإﻃـﺎر ﻣﻨﻄﻘﻲ ﻟﺮﺑﻂ اﻟ ﺮﺻﺪ ﺑﺎﻟﻨﻈﺮﻳﺔ . ﺗﻢ ﺗﺼﻨﻴﻊ ﻛﺎﻣ ا اﻟﻄﺎﻗﺔ ا ﻈﻠﻤﺔ ﺑﻮاﺳﻄﺔ وزارة اﻟﻄﺎﻗﺔ وﺗﻢ ﺗﺮﻛﻴﺒﻬﺎ ﻋـﲆ ﺗﻠﺴـﻜﻮب ﻓﻴﻜﺘ ـﻮر ﺑﻼﻧﻜـﻮ ﺑﻘﻄـﺮ 4 أﻣﺘ ـﺎر اﻟﺘــﺎﺑﻊ ﻟﻠﻤﺆﺳﺴﺔ اﻟﻮﻃﻨﻴـﺔ ﻟﻠﻌﻠـﻮم اﻷﻣﺮﻳﻜﻴـﺔ ﰲ ﻣﺮﺻﺪ ﻛﺮو ﺗﻮﻟﻮﻟﻮ ﰲ ﺗﺸﻴﲇ وﻫـﻮ ﺑﺮﻧـﺎﻣﺞ ﺨﺘـﱪ ﻧـﻮﻳﺮﻻب اﻟﺘـﺎﺑﻊ ﺆﺳﺴـﺔ اﻟﻌﻠــﻮم اﻟﻮﻃﻨﻴﺔ اﻻﻣﺮﻳﻜﻴﺔ . ﻟﻘﺪ أ ﴍف ﻋﲆ اﻟﺪراﺳﺔ ﺗﺮﻳﺴـﺘﺎن ﻻﻣـﱪت اﻟﺬي أﻛﻤﻞ ﻫﺬا اﻟﻌﻤﻞ ﻛﻄﺎﻟـﺐ د ﻛﺘـﻮراه ﰲ ﻣﻌﻬﺪ اﻟﺪراﺳﺎت اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﻔﻠﻜﻴﺔ ﺑﺠﺎﻣﻌﺔ دﻳﻴﻐﻮ ﺑﻮرﺗﺎﻟﻴﺲ ﰲ ﺗﺸﻴﲇ وﻫﻮ اﻵن ﺑﺎﺣـﺚ ﻣﺎ ﺑﻌﺪ اﻟـﺪﻛﺘﻮراه ﰲ ﻣﺮﻛـﺰ ﺟﺎﻣﻌـﺔ ﻏـﺮب أﺳﱰاﻟﻴﺎ ﰲ ا ﺮﻛﺰ اﻟﺪوﱄ ﻷﺑﺤﺎث ﻋﻠﻢ اﻟﻔﻠـﻚ اﻟﺮادﻳﻮي إﻳﻜﺮار ) .( ﻟﻘﺪ أﺟﺮى اﻟﻔﺮﻳﻖ اﻟﻌﻠﻤﻲ ﺑﺎ ﺳﺘﺨﺪام ﻣﺠﺎل اﻟﺮؤﻳﺔ اﻟﻬﺎﺋﻞ ﻟﻜﺎﻣ ا ) دي ﻛﺎم ( أﻛﱪ ﻋﻤﻠﻴﺔ ﺑﺤﺚ ﰲ اﻟﺴﻤﺎء ﻋﲆ اﻹ ﻃﻼق ﺣـﻮل ﻛـﻮازار ﻣـﻦ اﻟﻜـﻮن ا ﺒﻜـﺮ وذﻟـﻚ ﺑﻬـﺪف اﻟﻘﻴـﺎم ﺑ ﻤﺤﺎوﻟﺔ ﻟﻘﻴﺎس ﻛﺜﺎﻓﺔ ﺑﻴﺌﺘـﻪ ﻣـﻦ ﺧـﻼل ﺣﺴﺎب ﻋﺪد ا ﺠﺮات ا ﺮاﻓﻘﺔ ا ﺤﻴﻄﺔ . وﻹﺟـﺮاء ﺗﺤﻘﻴﻘ ـﺎﺗﻬﻢ اﺣﺘـﺎج اﻟﻔﺮﻳ ـﻖ إﱃ ﻛﻮا زار ﺑﻤﺴﺎﻓﺔ ﻣﺤﺪدة ﺟﻴﺪ .اً ﻟﺤﺴﻦ اﻟﺤﻆ ﻓﺈن اﻟﻜـﻮازار VIK J2348– 3054 ﻟﻪ ﻣﺴﺎﻓﺔ ﻣﻌﺮوﻓﺔ ﺗﻢ ﺗﺤﺪﻳﺪﻫﺎ ﻣـﻦ ــ