Free Astronomy Magazine November-December 2024 ARABIC VERSION

37 field of view providedan expansive look at its cos- mic neighbor- hood. Serendipitously, DECam is also equippedwitha narrowband filterperfectly matched for detecting its compan- iongalaxies. “Thisquasarstudyre- ally was the perfect storm,” says Lambert. “We had a quasar with a well-known distance, and DECam ontheBlancotelescopeofferedthe massivefieldofviewandexactfilter that we needed.” DECam’s specialized filter allowed the team to count the number of companion galaxies around the quasar by detecting a very specific type of light they emit, known as Lyman-alpha radiation. Lyman-al- pha radiation is a specific energy signature of hydrogen, produced when it is ionized and then recom- binedduringtheprocessofstarfor- mation. Lyman-alpha emitters are typicallyyounger,smallergalaxies, andtheirLyman-alphaemissioncan beusedasawaytoreliablymeasure their distances. Distancemeasurementsformultiple Lyman-alpha emitters can then be used to construct a 3D map of a quasar’s neighborhood. After sys- tematically mapping the region of spacearoundquasarVIKJ2348- andproposesapossibleexplanation for why they have turned out con- flicting results. No other survey of this kind has used a search area as large as the one provided by DE- Cam, so to smaller-area searches a quasar’s environment can appear deceptively empty. “DECam’s extremely wide view is necessary for studying quasar neighborhoods thoroughly. You re- ally have to open up to a larger area,” says Lambert. “This suggestsa reasonable explanation as to why previous observations are in conflict with one another.” The team also suggests an explanation for the lack of companion galaxies in the imme- diate vicinity of the quasar. They postulate that the intensity of the radiation from the quasar may be large enough to affect, or poten- tially stop, the formation of stars in these galaxies, making them invisi- ble to our observations. “Some quasars are not quiet neigh- bors,” says Lambert. “Stars in gal- axiesformfromgasthatiscold enough to collapse under its own gravity. Luminous quasars can po- tentiallybesobrightastoilluminate thisgasinnearbygalaxiesandheat it up, preventing this collapse.” Lambert’steamiscurrentlyfollow- ing up with additional observations to obtain spectra and confirm star formationsuppression.Theyalso plantoobserveotherquasarsto buildamorerobustsamplesize.    NOVEMBER-DECEMBER2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ﺗﺆﻛــﺪ ا ﻷرﺻــﺎد ــﺎﻣ ا اﻟﻄﺎﻗــﺔ اﻟﻤﻈﻠﻤــﺔ أﺟﺮ ــﺖ ﺎﺳــﺘﺨﺪام اﻟــ ) ــﺎم د ( ﺗﻮﻗﻌـﺎت ﻋﻠﻤـ ـﻮن اﻟﻤ ﻜـﺮﺗﺸـ ﻠﺖ ﻧﺸـﺄت ﻓـﻲ اﻟ ـﻮازارات اﻟـ ـﺄن اﻟ ﺎء اﻟﻔﻠـﻚ ــﺎﻟﻤﺠﺮات اﻟﻤﺮاﻓﻘــﺔ وﻟﻌــﺐ ﻣﺠـﺎل ﻓـﻲﻣﻨــﺎﻃﻖ ﻣــﻦ اﻟﻔﻀـﺎء ﻣﺄﻫﻮﻟــﺔ ﻜﺜﺎﻓــﺔ ـﺎﻣ ا ـﺔ ﻟ اﻟﺮؤ ﺔ اﻟﻮاﺳـﻊ ﻟﻠﻐﺎ ) ـﺎم د ـ اﻟـ ﻔﻼﺗـﺮ واﻟ ( ﺨﺎﺻﺔ دوراً ﺣﺎﺳـﻤﺎً ﻓـﻲ اﻟﻮﺻـــﻮل إﻟـــﻰﻫـــﺬا اﻻﺳـــﺘﻨﺘﺎج وﺗﻜﺸـــﻒ اﻷ رﺻـــﺎد ﻋـــﻦﺳـــ ﺐ ﺗﻮﺻـــﻞ اﻟﺪراﺳـــﺎت اﻟﺴـﺎ ﻘﺔ ـﺪ ﻛﺜﺎﻓـﺔ ﺗﺴـﻌﻰ إﻟـﻰ ﺗﺤﺪ اﻟـ ﻣﻨـﺎﻃﻖ ﻧﺸـﺄت ﻓــﻲ ـﻮازارات اﻟـ اﻟ اﻟ ﻮن اﻟﻤ ﻜﺮإﻟﻰ ﻧﺘﺎﺋﺞ ﻣﺘﻀﺎرﺔ . 37 ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4 [NOIRLab/NSF/AURA/M.Garlick/J.daSilva(Spaceengine)/M.Zamani] أرﺻﺎد ﺧﻼل ﺳﺎﺑﻘﺔ ﺑﺎﺳﺘﺨﺪام ﻣﺼﻔﻮﻓﺔ أﺗﺎﻛﺎﻣ ــﺎ اﻟﻜﺒـــ ة ﻟﻠﻤﻠﻴﻤـــﱰ ﺗﺤـــﺖ ا ﻠﻴﻤﱰ ) ﻣﺮﺻﺪ أ ﺎ ( وﻣﺠﺎل اﻟﺮؤﻳﺔ اﻟـﺬي ﺗﺒﻠﻎ ﻣﺴﺎﺣﺘﻪ ﺛـﻼث درﺟـــﺎت ﻣﺮﺑﻌـــﺔ ﻟﻜـﺎﻣ ا ) دي ﻛـﺎم ( ﻣﻤــﺎ وﻓــﺮ ﻧﻈــﺮة واﺳﻌﺔ اﻟﻨﻄﺎق ﻋـﲆ ﺟـــﻮاره اﻟﻜـــﻮﻧﻲ وﺑﻤﺤﺾ اﻟﺼﺪﻓﺔ ﺗﻢ ﺗﺠﻬﻴــﺰ ) دي ﻛــﺎم ( أﻳﻀـﺎ ﺑ ﻔﻠـﱰ ﺿـﻴﻖ اﻟﻨﻄــﺎق ﻣﻨﺎﺳــﺐ ﺗﻤﺎﻣــ ﺎً ﻻﻛﺘﺸــﺎف ا ﺠﺮات ا ﺮاﻓﻘﺔ ﻟﻪ . ﻳﻘـــﻮل ﻻﻣـــﱪت : " ﻛﺎﻧـــﺖ دراﺳـــﺔ ــــــ ﻣﺎ ﻫﻮ ﻣﺘﻮﻗﻊ ﺑﺎﻟﻨﺴـﺒﺔ ﻟﻠﻜـﻮ ازارات اﻟﺘـﻲ ﺗﻌﻴﺶ ﰲ ﻣﻨﺎﻃﻖ ﻛﺜﻴﻔﺔ وﻣﻊ ذﻟـﻚ ﻓﻮﺟﺌـﻮا ﺑﺎﻛﺘﺸﺎف أﻧـﻪ ﰲ ﺣـﺪود 15 ﻣﻠﻴـﻮن ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻣﻦ اﻟﻜﻮازار ﻟﻢ ﻳﻜﻦ ﻫﻨﺎك أي رﻓﺎق ﻋﲆ اﻹﻃﻼق . ﻳﺴﻠ ﻂ ﻫﺬا اﻻﻛﺘﺸﺎف اﻟﻀﻮء ﻋـﲆ ﺣﻘﻴﻘـﺔ اﻟﺪراﺳﺎت اﻟﺴﺎﺑﻘﺔ اﻟﺘﻲ ﺗﻬﺪف إﱃ ﺗﺼـﻨﻴﻒ ﺑﻴﺌﺎت اﻟﻜﻮازار ﰲ وﻗﺖ ﻣﺒﻜـﺮ ﻣـﻦ اﻟﻜـﻮن وﻳﻘﱰح ﺗﻔﺴ اً ﻣﻤﻜﻨﺎً ﻟﺴﺒﺐ ﻇﻬﻮر ﻧﺘﺎﺋﺞ ﻣﺘﻀﺎرﺑﺔ وﻟﻢ ﻳﺴﺘﺨﺪم أي ﻣﺴﺢ آﺧﺮ ﻣـﻦ ﻫﺬا اﻟﻨﻮع ﻣﻨﻄﻘ ﺔ ﺑﺤﺚ ﻛﺒ ة ﻣﺜﻞ ﺗﻠﻚ اﻟﺘﻲ ﻗﺪﻣﺘﻬﺎ ) ﻛﺎﻣ ا دي ﻛﺎم ( ﻟﺬﻟﻚ ﻗﺪ ﺗﺒﺪو ﺑﻴﺌﺔ ا ﻟﻜﻮاز ار ﻓﺎرﻏـﺔ ﺑﺸـﻜﻞ ﻏﺮﻳـﺐ ﻟﻌﻤﻠﻴـﺎت اﻟﺒﺤﺚ ﰲ ﻣﻨﺎﻃﻖ أﺻﻐﺮ . ﻳﻘﻮل ﻻﻣﱪت " : ﺑﻌـﺾ اﻟﻜـﻮازارات ﻟﻴﺴـﺖ ﺟ اﻧًﺎ ﻫﺎدﺋ . ﺗﺘﻜﻮن اﻟﻨﺠـﻮم ﰲ ا ﺠـﺮات ﻣﻦ ﻏـﺎز ﺑـﺎرد ﺑﻤـﺎ ﻳﻜﻔـﻲ ﻟﻴﻨﻬـﺎر ﺗﺤـﺖ ﺟﺎذﺑﻴﺘــﻪ اﻟﺨﺎﺻــﺔ . ﻳﻤﻜــﻦ أن ﺗﻜــﻮن اﻟﻜﻮازارات ا ﻀﻴﺌﺔ ﺷﺪﻳﺪة اﻟﺴﻄﻮع ﺑﺤﻴﺚ ﺗ ﻘﻮم ﺑﺈﺿﺎءة ﻫﺬا اﻟﻐﺎز ﰲ ا ﺠﺮ ات اﻟﻘﺮﻳﺒﺔ وﺗﺴﺨﻨﻪ ﻣﻤﺎ ﻳﻤﻨﻊ ﻫﺬا اﻻﻧﻬﻴﺎر . ﻳﺘﺎﺑﻊ ﻓﺮﻳﻖ ﻻﻣﱪت ﺣﺎﻟﻴ ﺎً ا ﺰﻳﺪ ﻣﻦ اﻷرﺻﺎد ﻟﻠﺤﺼﻮل ﻋﲆ اﻷﻃﻴﺎف وﺗﺄﻛﻴﺪ ﻗﻤﻊ ﺗﺸـﻜﻞ اﻟﻨﺠﻮم . ﻛﻤﺎ ﻳﺨﻄﻄﻮن ﺮاﻗﺒﺔ اﻟﻜـﻮازارات اﻷﺧﺮى ﻟﺒﻨﺎء ﺣﺠﻢ ﻋﻴﻨﺎت أﻛﺜﺮ ﻗﻮة . اﻟﻜﻮازار ﻫﺬه ﺑﻤﺜﺎﺑﺔ اﻟﻌﺎﺻﻔﺔ ا ﺜﺎﻟﻴﺔ ﺣﻘًﺎ . ﻟﻘﺪ ﻛﺎن ﻟ ﺪﻳﻨﺎ ﻛﻮازار ﺑﻤﺴﺎﻓﺔ ﻣﻌﺮوﻓﺔ ﺟﻴﺪاً وﻗﺪ ﻗﺪﻣﺖ ) ﻛﺎﻣ ا دي ﻛﺎم ( ﻋﲆ ﺗﻠﺴـﻜﻮب ﺑﻼﻧﻜﻮ ﻣﺠﺎل اﻟﺮؤﻳﺔ اﻟﻀﺨﻢ واﻟﻔﻠﱰ اﻟﺪﻗﻴﻖ اﻟﺬي ﻧﺤﺘﺎﺟﻪ ." ﺳﻤﺢ ا ﺮﺷﺢ ا ﺘﺨﺼﺺ ﰲ ) ﻛﺎﻣ ا دي ﻛـﺎم ( ﻟﻠﻔﺮﻳـﻖ ﺑﺤﺴـﺎب ﻋـﺪد ا ﺠﺮات ا ﺮاﻓﻘﺔ ﺣﻮل اﻟﻜﻮازار ﻣـﻦ ﺧـﻼل اﻛﺘﺸﺎف ﻧﻮع ﻣﺤﺪد ﻟﻠﻐﺎﻳﺔ ﻣﻦ اﻟﻀﻮء اﻟﺬي ﺗﻨﺒﻌﺚ ﻣﻨﻪ وا ﻌﺮوف ﺑﺎﺳﻢ إﺷـﻌﺎع ﻟﻴﻤـﺎن أﻟﻔﺎ . إﺷﻌﺎع ﻟﻴﻤﺎن أﻟﻔ ﺎ ﻫـﻮ ﺗﻮﻗﻴـﻊ ﻃﺎﻗـﺔ ﻣﺤﺪد ﻟﻠﻬﻴﺪروﺟ ﻳﻨﺘﺞ ﻋﻨﺪﻣﺎ ﻳﺘﻢ ﺗﺄﻳﻨﻪ ﺛﻢ إﻋﺎدة دﻣﺠﻪ أﺛﻨﺎء ﻋﻤﻠﻴﺔ ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم . ﻋﺎدةً ﻣﺎ ﺗﻜﻮن ﻣﺠﺮات ﻟ ﻴﻤـﺎن أﻟﻔـﺎ أﺻـﻐﺮ ﺳـﻨﺎ وأﺻـﻐﺮ ﺣﺠﻤـﺎ وﻳﻤﻜـﻦ اﺳـﺘﺨﺪام اﻧﺒﻌﺎﺛﺎت ﻟﻴﻤﺎن أﻟﻔـﺎ اﻟﺨﺎﺻـﺔ ﺑﻬـﺎ ﺑ ﻌﻴـﺪاً ﻟﻘﻴﺎس ﻣﺴﺎﻓﺎﺗﻬﺎ ﺑﺸﻜﻞ ﻳﻤﻜـﻦ و ﻣﻮﺛـﻮق ﺑﻌﺪ ذﻟﻚ اﺳﺘﺨﺪام ﻗﻴﺎﺳـﺎت ا ﺴـﺎﻓﺔ ﻣـﻦ ﺧﻼل ﻋﺪة ﺑﺎﻋﺜﺎت ﻟﻴﻤﺎن أﻟﻔﺎ ﻟﺒﻨﺎء ﺧﺮﻳﻄﺔ ﺛﻼﺛﻴﺔ اﻷﺑﻌﺎد ﻟﺠﻮار اﻟﻜـﻮازار . ﺑﻌـﺪ رﺳـﻢ ﺧﺮﻳﻄﺔ ﻣﻨﻬﺠﻴـﺔ ﻨﻄﻘـﺔ اﻟﻔﻀـﺎء ﺣـﻮل اﻟﻜﻮازار VIK J2348– 054 وﺟﺪ ﻻﻣـﱪت وﻓﺮﻳﻘــﻪ ٣٨ ﻣﺠ ـﺮة ﻣﺼــﺎﺣﺒﺔ ﰲ اﻟﺒﻴﺌ ـﺔ اﻷوﺳﻊ ﺣﻮل اﻟﻜﻮازار ﻋـﲆ ﻣﺴـﺎﻓﺔ ﺗﺼـ ﻞ إﱃ 60 ﻣﻠﻴﻮن ﺳﻨﺔ ﺿﻮﺋﻴﺔ وﻫﻮ ﻣﺎ ﻳﺘﻔﻖ ﻣﻊ