Free Astronomy Magazine September-October 2024

Three galaxies actively forming only 400 to 600 million years after theBigBang byNASA/ESA/CSA Claire Blome ChristinePulliam esearchersanalyzingdatafrom NASA’sJamesWebbSpaceTele- scopehavepinpointedthree galaxiesthatmaybeactivelyforming when the universe was only 400 to 600 million years old. Webb’s data showthesegalaxiesaresurrounded bygasthattheresearcherssuspect to be almost purely hydrogen and helium,theearliestelementstoexist in the cosmos. Webb’s instruments are so sensitive that they were able todetectanunusualamountofdense gas surrounding these galaxies. This gaswilllikelyendupfuelingthefor- mation of new stars in the galaxies. “Thesegalaxiesarelikesparkling islands in a sea of otherwise neu- tral, opaque gas,” explained Kasper Heintz, the lead author and an as- sistant professor of astrophysics at the Cosmic Dawn Center (DAWN) at theUniversityofCopenhageninDenmar k. “WithoutWebb,wewould notbeabletoobservethesevery earlygalaxies,letalonelearnso much about their formation.” “We’re moving away from a picture of galaxies as isolated ecosystems. At this stage in the history of theuniverse, galaxies are all intimately connectedtotheintergalacticmedium withitsfilamentsand structuresofpristinegas,” added SimoneNielsen,aco-authorand PhD student also based at DAWN. In Webb’simages,thegalaxieslook like faint red smudges, which is why extra data, known as spectra, were criticalfortheteam’sconclusions. ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 18 ﺛﻼثﻣﺠﺮات ﻧﺸﻄﺔ ﺗﺸ ﻠﺖ 400 إﻟﻰ 600 ﻣﻠﻴﻮنﺳﻨﺔ ﻌﺪ اﻻﻧﻔﺠﺎراﻟﻌﻈ ﻢ - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 4 : ﻘﻠﻢ ﺑﻮﻟ ﺎم ﻠ ﻠﻮم وﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ ﺣـﺪد اﻟﺒﺎﺣﺜﻮ اﻟﺬﻳ ن ﻦ ﻗﺎﻣﻮا ﺑﺘﺤﻠﻴﻞ ﺑﻴﺎﻧﺎت ﻣﻦ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳـﺎ ﺛـﻼث ﻣﺠـﺮات رﺑﻤـﺎ ﻛﺎﻧـﺖ ﺗﺘﺸﻜﻞ ﺑﺸﻜﻞ ﻧﺸﻂ ﻋﻨﺪﻣﺎ ﻛﺎن ﻋﻤﺮ اﻟﻜﻮن ﻳﱰاوح ﺑ 400 إﱃ 600 ﻣﻠﻴﻮن ﺳﻨﺔ ﻓﻘﻂ . ﺗﻈﻬـﺮ ﺑﻴﺎﻧ ـﺎت ﺗﻠﺴـﻜﻮب وﻳـﺐ أن ﻫـﺬه ا ﺠﺮات ﻣﺤﺎﻃﺔ ﺑﻐﺎز و ﻳﻌﺘﻘﺪ اﻟﺒﺎﺣﺜﻮن أﻧﻪ ﻳﺘﻜﻮن ﻣﻦ اﻟﻬﻴﺪروﺟ واﻟﻬﻴﻠﻴـﻮم ﺗﻘﺮﻳﺒـﺎً وﻫﻤﺎ اﻟﻌﻨﺎﴏ اﻷوﱃ اﻟﺘﻲ وﺟﺪت ﰲ اﻟﻜﻮن . إن أدوات ﺗﻠﺴﻜﻮب وﻳﺐ ﺣﺴﺎﺳـﺔ ﻟﺪرﺟـﺔ أﻧﻬﺎ ﺗﻤﻜﻨﺖ ﻣﻦ اﻛﺘﺸﺎف ﻛﻤﻴﺔ ﻏ ﻋﺎدﻳـﺔ ﻣﻦ ا ﻟﻐﺎز اﻟﻜﺜﻴﻒ ا ﺤﻴﻂ ﺑﻬﺬه ا ﺠﺮات وﻣﻦ ا ﺮﺟﺢ أن ﻳﺆدي ﻫـﺬا اﻟﻐـﺎز ﰲ اﻟﻨﻬﺎﻳـﺔ إﱃ ﺗﻐﺬﻳﺔ ﺗﻜـﻮﻳﻦ ﻧﺠـﻮم ﺟﺪﻳـﺪة ﰲ ا ﺠـﺮات . أوﺿﺢ ﻛﺎﺳـﱪ ﻫـﺎﻳﻨﺘﺰ ا ﺆﻟـﻒ اﻟﺮﺋـ ﻴﴘ ـ واﻷﺳﺘﺎذ ا ﺴـﺎﻋﺪ ﰲ اﻟﻔﻴﺰﻳـﺎء اﻟﻔﻠﻜﻴـﺔ ﰲ ﻣﺮﻛﺰ اﻟﻔﺠﺮ اﻟﻜﻮﻧﻲ ﰲ ﺟﺎﻣﻌﺔ ﻛﻮﺑﻨﻬـﺎﺟﻦ اﻟﺪﻧﻤﺎرك ﰲ " : ﺗﺸـﺒﻪ ﻫـﺬه ا ﺠـﺮات ﺟـﺰر اً ﻣﺘﻸﻟﺌﺔ ﰲ ﺑﺤﺮ ﻣﻦ اﻟﻐﺎزات ا ﺤﺎﻳ ﺪ وا ﻌـﺘﻢ وﺑﺪون ﺗﻠﺴﻜﻮب وﻳﺐ ﻟﻦ ﻧﻜﻮن ﻗﺎدرﻳﻦ ﻋﲆ ﻣﺮاﻗﺒﺔ ﻫﺬه ا ﺠﺮات ا ﺒﻜﺮة ﻣﺮاﻗﺒﺔ ﻫﺬه ا ﺠﺮات ا ﺒﻜﺮة و ﻣﻌﺮﻓﺔ اﻟﻜﺜ ﻋﻦ ﺗﻜﻮﻳﻨﻬﺎ . ﻧﺤﻦ ﻧﺒﺘﻌﺪ ﻋﻦ ﺻﻮر ة ا ﺠﺮات ﻛﺄﻧﻈﻤﺔ ﺑﻴﺌﻴـﺔ ﻣﻌﺰوﻟـﺔ . أﺿـﺎف ﺳـﻴﻤﻮن ﻧﻴﻠﺴﻦ ﻣﺆﻟﻒ ﻣﺸﺎرك وﻃﺎﻟـﺐ دﻛﺘـﻮراه ﰲ ﻣﺮﻛﺰ اﻟﻔﺠﺮ اﻟﻜﻮﻧﻲ :" ﰲ ﻫﺬه ا ﺮﺣﻠﺔ ﻣـﻦ ﺗﺎرﻳﺦ اﻟﻜﻮن ﺗ ﺮﺗﺒﻂ ﺟﻤﻴﻊ ا ﺠﺮات ارﺗﺒﺎﻃﺎ وﺛﻴﻘـ ﺎ ﺑﺎﻟﻮﺳـﻂ ﺑـ ا ﺠـﺮات ﺑﺨﻴﻮﻃـﻪ وﻫﻴﺎﻛﻞ ا ﻟﻐﺎز اﻟﺒﻜﺮ ﰲ ﺻﻮر و ﺗﻠﺴﻜﻮب وﻳﺐ ﺗﺒﺪو ا ﺠﺮات ﻛ ﺒﻘﻊ ﺣﻤـﺮاء ﺧﺎﻓﺘـﺔ ﺬا وﻟﻬـ ﻛﺎﻧﺖ اﻟﺒﻴﺎﻧﺎت اﻹﺿـﺎﻓﻴﺔ ا ﻌﺮوﻓـﺔ ﺑﺎﺳـﻢ اﻷﻃﻴﺎف ﻣﻬﻤﺔ ﰲ اﺳﺘﻨﺘﺎﺟﺎت اﻟﻔﺮﻳﻖ .