Free Astronomy Magazine September-October 2024

Those spectra show that light from thesegalaxiesisbeingabsorbedby large amounts of neutral hydrogen gas. “The gas must be very wide- spreadandcoveraverylargefrac- tion of the galaxy,” said Darach Watson, a co-author who is a pro- fessoratDAWN. “Thissuggeststhat weareseeingtheassemblyofneu- tral hydrogen gas into galaxies. That gas will go on to cool, clump, and form new stars.” The universe was a very different placeseveralhundredmillionyears afterthebigbangduringaperiod known as the Era of Reionization. Gas between stars and galaxies was largely opaque. Gas throughout the universe only became fully trans- parent around 1 billion years after the big bang. Galaxies’ stars con- tributedtoheatingandionizingthe gas around them, causing thegas to eventually become com- pletely transparent. BymatchingWebb’sdatatomodels of star formation, the researchers also found that these galaxies pri- marily have populations of young stars. “Thefactthatweareseeing large gas reservoirs also suggests that the galaxies have not had enough time to form most of their stars yet,” Watson added. Webb is not only meeting the mis- sion goals that drove its develop- ment and launch – it is exceeding them. “Images and data of these distantgalaxieswereimpossibleto obtain before Webb,” explained Gabriel Brammer, a co-author and associateprofessoratDAWN.“ Plus, we had a good sense of what we were going to find when we first glimpsedthedata–wewerealmost making discoveries by eye.” Thereremainmanymorequestions toaddress.Where,specifically,isthe gas? How much is located near the centers of the galaxies – or in their outskirts? Is the gas pristine or al- ready populated by heavier ele- ments? Significant research lies ahead. “The next step is to build largestatisticalsamplesofgalaxies and quantify the prevalence and prominenceoftheirfeaturesinde- tail,” Heintzsaid.     19 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ُﻈﻬﺮ ﻫـﺬا اﻟﺮﺳـﻢ اﻟﺘﻮﺿـﻴﺤﻲﻣﺠـﺮة ﺗﺘﺸـ ﻞ ﻌـــــﺪ ﻣﺎﺋـــــﺔ ﻣﻠﻴـــــﻮنﺳــــــﻨﺔ ﻓﻘـــــﻂ ﻣـــــﻦ اﻻﻧﻔﺠــــــﺎر اﻟﻌﻈـ ﻢ ــﺎرة ﻋــ ــﺎن اﻟﻐــﺎزﻋ ﻋﻨــﺪﻣﺎ ﻦ ﻣـﺰ ﺞ ﻣــﻦ اﻟﻐــــﺎز اﻟﺸــــﻔﺎ ف واﻟﻤﻌــــﺘﻢ ﺧــــﻼل ﻋﺼــــﺮ إﻋـــــﺎدة اﻟﺘـــــــــــﺄﻳﻦ وﺗﻈﻬــــــــــــﺮاﻟﺒ ﺎﻧــــــــــــﺎت اﻟﻤﺴــــــــــــﺘﻘﺎة ﻣــــــــــــﻦ ـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟ ﺗﻠﺴ ﻮب ﺟ ﻤﺲو ﻮ ﺎﻟـﺔ ــﺪ ــﺎرد اﻟﻤﺤﺎ ﻧﺎﺳــﺎ أن ﻫﻨــﺎك اﻟﻜﺜــ ﻣــﻦ اﻟﻐــﺎز اﻟ ﻓــــــــﻲ اﻟﻤﻨــــــــﺎﻃﻖ اﻟﻤﺠـــــــــﺎورة ﻟﻬــــــــﺬ ﻩ اﻟﻤﺠـــــــــﺮات اﻟﻤ ﻜــﺮة ـــﻮن أﻛــ ﻛﺜﺎﻓــﺔ ﻣﻤـــﺎ وأن اﻟﻐــﺎزﻗــﺪ ﻳ ــــــــﺎن ﻣﺘﻮﻗﻌـــــــــﺎ . رﺻـــــــــﺪ ﺗﻠﺴــــــــ ﻮب ـــــــــﺐ ﻫـــــــــﺬﻩ و اﻟﻤﺠﺮات ﺠﺰء ﻣﻦ ﻣﺴﺢ ﻋﻠﻮم اﻹﺻﺪاراﻟﻤ ﻜﺮ ـﻮﻧﻲ ﻟﻠﺘﻄــﻮراﻟ ) CEERS ( ﻌــﺪ ﻀـﻌﺔ أﺷــﻬﺮ ـــــــﺎت اﻟﺮﺻـــــــﺪ ﻓـــــــﻲﻋــــــــﺎم ـــــــﺪء ﻋﻤﻠ ﻣـــــــﻦ 2022 . واﻟـــــــﺬ ــــــــﻼً ﻣــــــــﻦ اﻟﺼــــــــﻮرواﻟﺒ ﺎﻧــــــــﺎت ﺘﻀــــــــﻤﻦ ـــــــــﺎفﻣـــــــــﻦ اﻟﻤﻌﺮوﻓـــــــــﺔ ﺎﺳـــــــــﻢ اﻷﻃ اﻟﻔﻮاﻟـــــــــﻖ ﻧ ﺳﺒ ﻚ اﻟﺪﻗ ﻘﺔ اﻟﻤﻮﺟﻮدة ﻋﻠﻰﻣ . ) ــﺎف اﻷﺷـــﻌﺔ ﺗﺤـــﺖ اﻟـــ ﻣﻄ ـ ـــﺔ ﻤﺮاء اﻟﻘﺮ ﺗـــﻢ (. إﺻـﺪاراﻟﺒ ﺎﻧــﺎت ﻣـﻦ CEERS ﻟــﺪﻋﻢ اﻛﺘﺸــﺎﻓﺎت ﻣﺜــــﻞ ﻫــــﺬﻩ ﺠــــﺰء ﻣــــﻦ ﺑﺮــــﺎﻣﺞ اﻟﻨﺸــــﺮ اﻟﻌﻠﻤــــﻲ اﻟﻤ ﻜﺮﻟﺘﻠﺴ ﻮب و ﺐ . ﺗﻈﻬﺮ ﻫﺬه اﻷﻃﻴﺎف أن اﻟﻀﻮء اﻟﺼﺎدر ﻣـﻦ ﻫـﺬه ا ﺠـﺮات ﻳـﺘﻢ اﻣﺘﺼﺎﺻـﻪ ﺑﻮاﺳـﻄﺔ ﻛﻤﻴﺎت ﻛﺒ ة ﻣﻦ ﻏﺎز اﻟﻬﻴﺪروﺟ ا ﺤﺎﻳـﺪ . ﻗــﺎل داراش واﺗﺴــﻮن ا ﺆﻟــﻒ ا ﺸــﺎرك واﻷﺳﺘﺎذ ﰲ ﻣﴩوع اﻟﻔﺠﺮ اﻟﻜﻮﻧﻲ " : ﻳﺠﺐ أن ﻳﻜﻮن اﻟﻐﺎز ﻣﻨﺘﴩ اً ﻋـﲆ ﻧﻄـﺎق واﺳـﻊ ﺟﺪاً وﻳﻐﻄﻲ ﺟﺰء اً اً ﻛﺒـ اً ﺟـﺪ ﻣـﻦ ا ﺠـﺮة وﻫـﺬا ﻳﺸـ إﱃ أﻧﻨـﺎ ﻧﺸـﻬﺪ ﺗﺠﻤــﻊ ﻏـﺎز اﻟﻬﻴﺪروﺟ ا ﺤﺎﻳﺪ ﰲ ا ﺠﺮات وﺳﻴﺴـﺘﻤﺮ ﻫﺬا اﻟﻐﺎز ﰲ اﻟﺘﱪﻳـﺪ واﻟﺘﻜﺘـﻞ ﻣـﻊ ﺑﻌﻀـﻪ وﺗﺸﻜﻴﻞ ﻧﺠﻮم ﺟﺪﻳﺪة . ﻟﻘﺪ ﻛﺎن اﻟﻜﻮن ﻣﻜﺎﻧ ﺎً ﻣﺨﺘﻠﻔًﺎ ﺗﻤﺎﻣـ ﺎً ﺑﻌـﺪ ﻋﺪة ﻣﺌﺎت ﻣﻦ ﻣﻼﻳ اﻟﺴﻨ ﻣﻦ اﻻﻧﻔﺠـﺎر ــ اﻟﻌﻈﻴﻢ ﺧﻼل ﻓﱰة ﺗُﻌﺮف ﺑﺎﺳﻢ ﺣﻘﺒﺔ إﻋﺎدة اﻟﺘـﺄﻳﻦ ﻛـﺎن اﻟﻐـﺎز ا ﻮﺟـﻮد ﺑـ اﻟﻨ ﺠـﻮم وا ﺠﺮات ﻣﻌﺘﻤﺎً إﱃ ﺣﺪ ﻛﺒـ وﻟـﻢ ﻳﺼـﺒﺢ اﻟﻐﺎز ﰲ ﺟﻤﻴﻊ أ ﻧﺤﺎء اﻟﻜﻮن ﺷﻔﺎﻓ ﺎً إﻻ ﺎً ﺗﻤﺎﻣ ﺑﻌﺪ ﺣﻮ اﱄ ﻣﻠﻴﺎر ﺳﻨﺔ ﻣﻦ اﻻﻧﻔﺠﺎر اﻟ ﻌﻈـﻴﻢ وﻗﺪ ﺳـﺎﻫﻤﺖ ﻧﺠـﻮم ا ﺠـﺮات ﰲ ﺗﺴـﺨ وﺗﺄﻳﻦ اﻟﻐﺎز ا ﺤﻴﻂ ﺑﻬﺎ ﻣﻤـﺎ ﺟﻌـﻞ اﻟﻐـﺎز ﻳ ﺼﺒﺢ ﺷﻔﺎﻓﺎ ﺗﻤﺎﻣﺎ ﰲ ﻧﻬﺎﻳﺔ ا ﻄﺎف . ﺑﻌـﺪ ذﻟـﻚ و ﻣـﻦ ﺧـﻼل ﻣﻄﺎﺑﻘـﺔ ﺑﻴﺎﻧـﺎت ﺗﻠﺴﻜﻮب وﻳﺐ ﻣﻊ ﻧﻤﺎذج ﺗﻜـﻮﻳﻦ اﻟﻨﺠـﻮم وﺟـﺪ اﻟﺒـﺎﺣﺜﻮن أﻳﻀـﺎَ أن ﻫـﺬه ا ﺠـﺮات ﺗﺤﺘﻮي ﰲ ا ﻘﺎم اﻷول ﻋﲆ ﻣﺠﻤﻮﻋﺎت ﻣـﻦ اﻟﻨﺠ ـﻮم اﻟﺸ ـﺎﺑﺔ . أﺿ ـﺎف واﺗﺴ ـﻮن " : إن ــــــ ﺣﻘﻴﻘﺔ رؤ ﻳﺘﻨﺎ ﻟﺨﺰاﻧﺎت ﻏﺎز ﻛﺒـ ة ﺗﺸـ أﻳﻀ ﺎً إﱃ أن ا ﺠﺮات ﻟﻢ ﻳﻜﻦ ﻟـﺪﻳﻬﺎ اﻟﻮﻗـﺖ اﻟﻜﺎﰲ ﻟﺘﻜﻮﻳﻦ ﻣﻌﻈﻢ ﻧﺠﻮﻣﻬﺎ ﺑﻌﺪ ." ﻟﻢ ﻳﺤﻘﻖ ﺗﻠﺴﻜﻮب وﻳﺐ أﻫﺪاف ا ﻬﻤﺔ ا ﻟﺘﻲ أدت إﱃ ﺗﻄــﻮﻳﺮه وإﻃﻼﻗــﻪ ﻓﺤﺴــﺐ ﺑــﻞ ﺗﺠﺎوزﻫﺎ أﻳﻀﺎً . أوﺿـﺢ ﻏﺎﺑﺮﻳﻴـﻞ ﺑﺮاﻣـﺮ ا ﺆﻟـﻒ ا ﺸـﺎرك واﻷﺳﺘﺎذ ا ﺸﺎرك ﰲ ﺑﺮﻧﺎﻣﺞ اﻟﻔﺠﺮ اﻟﻜﻮﻧﻲ : ﻟﻘﺪ " ﻛﺎن ﻣﻦ ا ﺴﺘﺤﻴﻞ اﻟﺤﺼﻮل ﻋ ﲆ ﺻﻮر وﺑﻴﺎﻧــﺎت ﻟﻬــﺬه ا ﺠــﺮات اﻟﺒﻌﻴــﺪة ﻗﺒــﻞ ﺗﻠﺴﻜﻮب وﻳﺐ ﻛﺎن ﻟﺪﻳﻨﺎ إﺣﺴﺎسﺟﻴﺪ ﺑﻤـﺎ ﺳﻨﺠﺪه ﻋﻨﺪﻣﺎ أﻟﻘﻴﻨﺎ ﻧ ﻈـﺮة ﺧﺎﻃﻔـﺔ ﻋـﲆ اﻟﺒﻴﺎﻧﺎت ﻷول ﻣﺮة وﻛﻨﺎ ﻋﲆ وﺷـﻚ ﺗ ﺤﻘﻴـﻖ اﻻﻛﺘﺸﺎﻓﺎت ﺑﺎﻟﻌ ا ﺠﺮدة «. ﻻ ﺗﺰال ﻫﻨﺎك اﻟﻌﺪﻳﺪ ﻣﻦ اﻷﺳﺌﻠﺔ اﻟﺘﻲ ﻳﺠـﺐ اﻹﺟﺎﺑﺔ ﻋﻠﻴﻬﺎ ﺑﺎﻟﺘﻔﺼﻴﻞ . أﻳ ﻦ ﻳﻮﺟﺪ اﻟﻐﺎز ﻋ ﲆ وﺟﻪ اﻟﺘﺤﺪﻳﺪ؟ ﻫﻞ ﻳﻘﻊ ﺑﺎﻟﻘﺮب ﻣﻦ ﻣﺮاﻛﺰ ا ﺠﺮات أﰲ أم ﻃﺮاﻓﻬـﺎ؟ ﻫـﻞ اﻟﻐـﺎز ﻧﻘـﻲ أم أﻧـﻪ ﻣـﺄﻫﻮل ﺑﺎﻟﻔﻌـﻞ ﺑﻌﻨﺎﴏ أﺛﻘﻞ؟ ﻫﻨﺎك أﺑﺤﺎث ﻋﺪﻳﺪة و ﻣﻬﻤـﺔ ﺗﻨﺘﻈﺮﻧﺎ ﻟﻠﻘﻴﺎم ﺑﻬﺎ . ﻗﺎل ﻫﺎﻳﻨﺘﺰ " : إن اﻟﺨﻄﻮة اﻟﺘﺎﻟﻴﺔ ﻫﻲ ﺑﻨـﺎء أﻛﱪ ﻋﻴﻨﺎت إﺣﺼﺎﺋﻴﺔ ﻣﻦ ا ﺠﺮات وﻗﻴـﺎس ﻣﺪى اﻧﺘﺸﺎر وﺑﺮوز ﺳﻤﺎﺗﻬﺎ ﺑﺎﻟﺘﻔﺼﻴﻞ ." - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4