Free Astronomy Magazine March-April 2024 ARABIC VERSION

Distant galaxies have flattened oval disk and tube-like shapes by NASA/ESA/CSA − Claire Blome 5 Christine Pulliam esearchers analyzing images from NASA’s James Webb Space Telescope have found that galaxies in the early universe are often flat and elongated, like surfboards and pool noodles – and are rarely round, like volleyballs or frisbees. “Roughly 50 to 80% of the galaxies we studied appear to be flattened in two dimensions,” ex- plained lead author Viraj Pandya, a NASA Hubble Fellow at Columbia University in New York. “Galaxies that look like pool noodles or surf- boards seem to be very common in the early universe, which is surpris- ing, since they are uncommon nearby.” The team focused on a vast field of near-infrared images deliv- ered by Webb, known as the Cosmic Evolution Early Release Science (CEERS) Survey, plucking out galax- ies that are estimated to exist when the universe was 600 million to 6 billion years old. While most distant galaxies look like surfboards and pool noodles, others are shaped like frisbees and volley- balls. The “volleyballs,” or sphere- shaped galaxies, appear the most compact type on the cosmic “ocean” and were also the least frequently identified. The frisbees were found ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 42 ﻣﺠﺮات ﻌ ﺪة ﻟﻬﺎﺷ ﻞ اﻟﻄﺒﻖ اﻟ ﺒ ﻀﺎوي اﻟﻤﺴﻄﺢ أ وﺷ ﻞ ﻻﻧﺒﻮب : ﻘﻠﻢ ﻠ ﻠﻮم و ﺑﻮﻟ ﺎم ﻛﺮﺴﺘ و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 4 اﻟﺼﻮر ﺣﺼﻞ ﻋﻠﻴﻬﺎ ﺗﻠﺴ ﻮبﺟ ﻤﺲو ﺐ اﻟﻔﻀﺎﺋﻲ ﺎﺳـﺘﺨﺪام أداة ﻋ ﺎرة ﻋﻦ ﻣ ﻤﻮﻋﺔ ﻣﻦ اﻟﺘﻌﺮﻀﺎت اﻟﻤﻨﻔﺼﻠﺔ اﻟ ـﺎم ) ﻧ ( ﺗـﻢ اﺳـﺘﺨﺪام ﻋـﺪة ﻣﺮﺷـﺤﺎت ﻷﺧـﺬ ﻋ ﻨــﺎت ﻣــﻦ ﻧﻄﺎﻗــﺎت اﻟﻄـﻮل اﻟﻤــ ﻮﺟﻲ اﻟﻮاﺳــﻌﺔ . ﻨـﺘﺞ اﻟﻠـﻮن ﻣــﻦ ﺗ ــﺪ ﺤﺪ ﺗــﺪرﺟﺎت أﻟــﻮان ) ( ــﺔ اﻟﻠـﻮن ـﻞ ﺻــﻮرة أﺣﺎد ﻣﺨﺘﻠﻔــﺔ ﻟ ) ﺗــﺪرج رﻣـﺎد ( ﻣﺮ ﻄــﺔ ﻤﺮﺷـﺢ . ﻓﺮد اﻛﺘﺸـﻒ اﻟﺒـﺎﺣﺜﻮن اﻟـﺬﻳﻦ ﻗـﺎﻣﻮا ﺑﺘﺤﻠﻴـﻞ اﻟﺼﻮر ا ﺄﺧﻮذة ﻣﻦ ﺗﻠﺴﻜﻮب ﺟـﻴﻤﺲ وﻳـﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳـﺎ أن ا ﺠـﺮات ﰲ ﺑﺪاﻳـﺔ اﻟﻜﻮن ﻏﺎﻟﺒًﺎ ﻣﺎ ﺗﻜﻮن ﻣﺴﻄﺤﺔ وﻣﺴـﺘﻄﻴﻠﺔ، ﻣﺜﻞ أﻟـﻮاح رﻛـﻮب اﻷﻣـﻮاج وأﻃﺒـﺎق ﺣﻤـﺎم ا ﻟﺴﺒﺎﺣﺔ، وﻧﺎدرًا ﻣـﺎ ﺗﻜـﻮن ﻣﺴـﺘﺪﻳﺮة ﻣﺜـﻞ ﻟﻜﺮ ا ات اﻟﻄﺎﺋﺮة أو اﻷﻃﺒﺎق اﻟﻄـﺎﺋﺮة أ. وﺿـﺢ ا ﺆﻟﻒ اﻟﺮﺋﻴﴘ ﻓ اج ﺑﺎﻧـﺪﻳﺎ زﻣﻴـﻞ ﻫﺎﺑـﻞ ﰲ ﻧﺎ ﺳﺎ ﰲ ﺟﺎﻣﻌﺔ ﻛﻮﻟﻮﻣﺒﻴﺎ ﰲ ﻧﻴﻮﻳـﻮرك ": ﻣـﺎ ﻳﻘـﺮب ﻣـﻦ 50 إﱃ 80 ٪ ﻣـﻦ ا ﺠـﺮات اﻟﺘـﻲ درﺳﻨﺎﻫﺎ ﺗﺒﺪو ﻣﺴﻄﺤﺔ ﰲ ﺑﻌﺪﻳﻦ " ـــــ درﺳﻨﺎﻫﺎ ﺗﺒﺪو ﻣﺴﻄﺤﺔ ﰲ ﺑﻌﺪﻳﻦ " . ﻳﺒـﺪو أن ا ﺠﺮات اﻟﺘﻲ ﺗﺸﺒﻪ ﺣﻮض اﻟﺴﺒﺎﺣﺔ أو أﻟـﻮاح رﻛﻮب اﻷﻣﻮاج ﻛﺎﻧﺖ ﺷـﺎﺋﻌﺔ ﺟـﺪاً ﰲ اﻟﻜـﻮن ا ﺒﻜﺮ وﻫﻮ أﻣـﺮ ﻣﺜـ ﻟﻠﺪﻫﺸـﺔ ﻷﻧﻬـﺎ ﻏـ ﺷﺎﺋﻌﺔ ﰲ ﻣﻜﺎن ﻗﺮﻳﺐ ". رﻛـﺰ اﻟﻔﺮﻳـﻖ ﻋـﲆ ﻣﺠﺎل واﺳﻊ ﻣﻦ اﻟﺼﻮر اﻟﻘﺮﻳﺒﺔ ﻣﻦ اﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﺘﻲ ﻗﺪﻣﻬﺎ وﻳـﺐ، وا ﻌﺮوﻓـﺔ ﺑﺎﺳﻢ ا ﺴﺢ اﻟﻌﻠﻤﻲ ﻟﻠﺘﻄﻮر ا ﺒﻜـﺮ ﻟﻠﺘﻄـﻮر اﻟﻜﻮﻧﻲ ) CEERS ( ﺣﻴﺚ اﺳﺘﺨﺮﺟﻮا ا ﺠـﺮات ا ﻟﺘﻲ ﻳﻘﺪر أﻧﻬﺎ ﻛﺎﻧﺖ ﻣﻮﺟـﻮدة ﻋﻨـﺪﻣﺎ ﻛـﺎن ﻋﻤﺮ اﻟﻜﻮن ﻣﺎ ﺑ ٦٠٠ ﻣﻠﻴﻮن إﱃ ٦ ﻣﻠﻴﺎرات ﻋﻤﺮ اﻟﻜﻮن ﻣﺎ ﺑ 600 ﻣﻠﻴﻮن إﱃ 6 ﻣﻠﻴﺎرات .ﺳﻨﺔ ﰲ ﺣ أن ﻣﻌﻈﻢ ا ﺠﺮات اﻟﺒﻌﻴﺪة ﺗﺒﺪو ﻣﺜﻞ أﻟﻮاح رﻛﻮب اﻷﻣﻮاج واﻻﺳﻔﻨﺞ ﻋﲆ ﺷﻜﻞ ا ﻜﺮوﻧﻪ ، ﻓﺈن اﻟﺒﻌﺾ اﻵﺧـﺮ ﻳﺸـﺒﻪ اﻗـﺮاص اﻟﻔﺮﻳﺴﺒﻲ واﻟﻜﺮات اﻟﻄﺎﺋﺮة . " ﺗﺒﺪو اﻟﻜﺮات اﻟﻄﺎﺋﺮة ، أو " ا ﺠﺮات اﻟﻜﺮوﻳـﺔ اﻟﺸﻜﻞ ﻫﻲ اﻟﻨﻮع ا ﻷﻛﺜﺮ إﺣﻜﺎﻣﺎ ﰲ ا ﺤﻴﻂ " " اﻟﻜﻮﻧﻲ ﻛﻤﺎ أﻧﻬﺎ اﻷﻗﻞ ﺗﺤﺪﻳـﺪا ﰲ ﻛﺜـ ﻣـﻦ اﻷﺣﻴﺎن وُﺟﺪ أن اﻷﻟﻮاح اﻟﻄﺎﺋﺮﻳﺔ ﻛﺒ ة ﻣﺜـﻞ ﻟـﻮح رﻛـﻮب اﻷﻣـﻮاج وا ﺠـﺮات ذات ﺷـﻜﻞ ا ﻌﻜﺮوﻧﺔ ﻋﲆ ﻃﻮل اﻷﻓﻖ " " ، وﻟﻜﻨﻬﺎ ﺗﺼـﺒﺢ