Free Astronomy Magazine March-April 2024 ARABIC VERSION

to be as large as the surfboard- and pool noodle-shaped galaxies along the “horizon,” but become more common closer to “shore” in the nearby universe. Which category would our Milky Way galaxy fall into if we were able to wind the clock back by billions of years? “Our best guess is that it might have appeared more like a surfboard,” said co-author Haowen Zhang, a PhD candidate at the Uni- versity of Arizona in Tucson. This hy- pothesis is based partly on new evidence from Webb – theorists have “wound back the clock” to es- timate the Milky Way’s mass billions of years ago, which correlates with shape at that time. These distant galaxies are also far less massive than nearby spirals and ellipticals – they are precursors to more massive galaxies like our own. “In the early universe, galaxies had had far less time to grow,” said Kartheik Iyer, a co-author and NASA Hubble Fellow also at Columbia Uni- versity. “Identifying additional cate- gories for early galaxies is exciting – there’s a lot more to analyze now. We can now study how galaxies’ shapes relate to how they look and better project how they formed in much more detail.” Webb’s sensitivity, high-resolution images, and specialization in in- frared light allowed the team to make quick work of characterizing many CEERS galaxies, and model their 3D geometries. Pandya also says their work wouldn’t be possible without the extensive research as- tronomers have done using NASA’s Hubble Space Telescope. For decades, Hubble has wowed us with images of some of the earliest galaxies, beginning with its first “deep field” in 1995 and continuing with a seminal survey known as Cos- mic Assembly Near-infrared Deep Extragalactic Legacy Survey. Deep sky surveys like these led to far greater statistics, leading as- tronomers to create robust 3D mod- els of distant galaxies over all of cosmic time. Today, Webb is helping to enhance these efforts, adding a bounty of distant galaxies beyond Hubble’s reach and revealing the early universe in far greater detail than previously possible. Webb’s images of the early universe have acted like an ocean swell – de- livering new waves of evidence. “Hubble has long showed an excess of elongated galaxies,” explained co-author Marc Huertas-Company, a faculty research scientist at the Insti- tute of Astrophysics on the Canary Islands. But researchers still won- dered: Would additional detail show up better with sensitivity to infrared light? “Webb confirmed that Hub- ble didn’t miss any additional fea- tures in the galaxies they both ob- served. Plus, Webb showed us many more distant galaxies with similar shapes, all in great detail.” There are still gaps in our knowl- edge – researchers not only need an even larger sample size from Webb to further refine the properties and precise locations of distant galaxies, they will also need to spend ample time tweaking and updating their models to better reflect the precise geometries of distant galaxies. “These are early results,” said co-au- thor Elizabeth McGrath, an associate professor at Colby College in Water- ville, Maine. “We need to delve more deeply into the data to figure out what’s going on, but we’re very ex- cited about these early trends.”     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 43 أﻣﺜﻠﺔ ـﺐ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟﻨﺎﺳـﺎ ﻓـﻲ ﻣﺴـﺢ اﻟﺘﻘﻄﻬـﺎ ﺗﻠﺴـ ﻮبﺟـ ﻤﺲو ﻋﻠﻰ اﻟﻤﺠﺮات اﻟ ﻌ ﺪة اﻟ ـﻮﻧﻲ ﻋﻠﻮم اﻹﺻﺪاراﻟﻤ ﻜﺮ ﻟﻠﺘﻄـﻮر اﻟ ) CEERS .( أﻇﻬـﺮ اﻷﺑﺤـﺎث ا ﺪ ﺜـﺔ ﻓـﻲﻣﺠـﺎل CEERS ـﺎدة ﻘ ـﺎن ﻓـ اج ﺎﻧــﺪ ﺎ أن اﻟﻤﺠــﺮات ﺗﻈﻬــﺮﻓــﻲﻛﺜــ ﻣــﻦ اﻷﺣ ﻣﻔﻠﻄﺤــﺔ وﻣﻤــﺪودة، ﻣﺜــﻞ اﻟﻤﻌﻜﺮوﻧــﺔ أو أﻟــﻮاح ـــﻮب اﻷﻣـــﻮاج ر ) ﻋﻠـــﻰﻃـــﻮل اﻟﺼـــﻒ اﻟﻌﻠـــﻮي .( اﻟﻤﺠـــﺮات اﻟ ﺗﺸـــ ﮫ اﻟﻘـــﺮص ﺮﻗ ﻘـــﺔ واﻟﺪاﺋﺮ ـــﺔ اﻟـــ واﻟـــ ــﺔ ــﺎق اﻟﻄــﺎﺋﺮة، ﻫــﻲ اﻟﻤ ﻤﻮﻋــﺔ اﻟﺮ ﺴــ ﺔ اﻟﺘﺎﻟ ﺗﺸــ ﮫ اﻷﻃ ) أﺳــﻔﻞ اﻟ ﺴــﺎر واﻟﻮﺳــﻂ .( وأﺧــً ا، ﺷــ ﻠﺖ اﻟﻤﺠـﺮات ذات اﻟﺸـ ﻞ اﻟﻜــﺮوي أو اﻟﻜـﺮات اﻟﻄــﺎﺋﺮة أﺻــﻐﺮﺟـﺰء ﻣــﻦ اﻛﺘﺸــﺎﻓﺎﺗﻬﺎ ) أﺳـﻔﻞ اﻟ ﻤـ .( وﺗﺸــ ـ اوح ﺑـ ـﻮن اﻟﺘﻘﺪﻳﺮات إﻟﻰ أن ﻞ ﻫﺬﻩ اﻟﻤﺠﺮات ﺎﻧﺖ ﻣﻮﺟﻮدة ﻋﻨﺪﻣﺎ ﺎن ﻋﻤـﺮاﻟ 600 ﻣﻠﻴـﻮن إﻟـﻰ 6 ﻣﻠ ﺎراتﺳﻨﺔ . ا ﻌﻜﺮوﻧﺔ ﻋﲆ ﻃﻮل اﻷﻓﻖ " " ، وﻟﻜﻨﻬﺎ ﺗﺼـﺒﺢ أﻛﺜﺮ ﺷﻴﻮﻋﺎً ﺑﺎﻟﻘﺮب ﻣﻦ " اﻟﺸﺎﻃﺊ " ﰲ اﻟﻜﻮن اﻟﻘﺮﻳﺐ . ﻣﺎ ﻫﻲ اﻟﻔﺌﺔ اﻟﺘﻲ ﺳﺘﻘﻊ ﻓﻴﻬﺎ ﻣﺠﺮﺗﻨـﺎ درب اﻟﺘﺒﺎﻧﺔ إذا ﺗﻤﻜﻨﺎ ﻣﻦ إرﺟﺎع ﻋﻘﺎرب اﻟﺴﺎﻋﺔ إﱃ اﻟﻮراء ﺑﻤﻠﻴﺎرات اﻟﺴﻨ ؟ ﻗﺎل ا ﺆﻟﻒ ا ﺸـﺎرك ﻫـﺎوﻳﻦ ﺗﺸـﺎﻧﻎ، وﻫـﻮ ﻣﺮﺷﺢ ﻟﺪرﺟﺔ اﻟﺪﻛﺘﻮراه ﰲ ﺟﺎﻣﻌﺔ أرﻳﺰوﻧﺎ ﰲ ﺗﻮﻛﺴﻮن " : أﻓﻀﻞ ﺗﺨﻤ ﻟﺪﻳﻨﺎ ﻫﻮ أﻧﻪ رﺑﻤـﺎ ﺑﺪا وﻛﺄﻧﻪ ﻟﻮح رﻛﻮب اﻷﻣﻮاج ." ﺗﻌﺘﻤﺪ ﻫﺬه اﻟﻔﺮﺿﻴﺔ ﺟﺰﺋﻴًﺎ ﻋﲆ أدﻟﺔ ﺟﺪﻳـﺪة ﻣﻦ وﻳـﺐ، ﺣﻴـﺚ ﻗـﺎم ا ﻨﻈـﺮون " ﺑﺈرﺟـﺎع ﻋﻘﺎرب اﻟﺴﺎﻋﺔ إﱃ اﻟﻮراء " ﻟﺘﻘﺪﻳﺮ ﻛﺘﻠـﺔ درب اﻟﺘﺒﺎﻧﺔ ﻣﻨﺬ ﻣﻠﻴﺎرات اﻟﺴﻨ ، وﻫﻮ ﻣﺎ ﻳـﺮﺗﺒﻂ ﺑﺎﻟﺸـﻜﻞ ﰲ ذﻟـﻚ اﻟﻮﻗـﺖ إن . ﻫـﺬه ا ﺠـﺮات اﻟﺒﻌﻴﺪة أﻳﻀًﺎ أﻗﻞ ﻛﺘﻠـﺔ ﺑﻜﺜـ ﻣـﻦ ا ﺠـﺮا ت اﻟﺤﻠﺰوﻧﻴﺔ واﻹﻫﻠﻴﻠﺠﻴﺔ اﻟﻘﺮﻳﺒﺔ وﻫﻲ ﻣﻘﺪﻣـﺔ ﺠﺮات أﻛﺜﺮ ﺿﺨﺎﻣﺔ ﻣﺜﻞ ﻣﺠﺮﺗﻨﺎ . ﻗﺎل ﻛﺎرﺛﻴﻚ آﻳﺮ ا ﺆﻟﻒ ا ﺸﺎرك وزﻣﻴﻞ ﻧﺎﺳـﺎ ﻫﺎﺑﻞ أﻳﻀًﺎ ﰲ ﺟﺎﻣﻌـﺔ ﻛﻮﻟﻮﻣﺒﻴـﺎ " : ﰲ ﺑﺪاﻳـﺔ اﻟﻜﻮن، ﻛﺎن ﻟﺪى ا ﺠـﺮات وﻗـﺖ أﻗـﻞ ﺑﻜﺜـ ﻟﻠﻨﻤﻮ ." " إن ﺗﺤﺪﻳﺪ ﻓﺌﺎت إﺿﺎﻓﻴﺔ ﻟﻠﻤﺠـﺮات ا ﺒﻜـﺮة أﻣﺮ ﻣﺜ - ﻫﻨﺎك اﻟﻜﺜ ﻟﺘﺤﻠﻴﻠﻪ اﻵن . ﻳﻤﻜﻨﻨـﺎ اﻵن دراﺳﺔ ﻛﻴﻔﻴﺔ ارﺗﺒـﺎط أﺷـﻜﺎل ا ﺠـﺮات ﺑﻤﻈﻬﺮﻫـﺎ وﺗﻘـﺪﻳﻢ ﻋـﺮض أﻓﻀـﻞ ﻟﻜﻴﻔﻴـﺔ ﺗﺸﻜﻠﻬﺎ ﺑﻤﺰﻳﺪ ﻣﻦ اﻟﺘﻔ .ﺼﻴﻞ ﻟﻘﺪ ﺳﻤﺤﺖ ﺣﺴﺎﺳﻴﺔ ﺗﻠﺴﻜﻮب وﻳﺐ واﻟﺼﻮر ﻋﺎﻟﻴﺔ اﻟﺪﻗﺔ واﻟﺘﺨﺼﺺﰲ ﺿﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤ ـﺮاء ﻟﻠﻔﺮﻳ ـﻖ ﺑﺎﻟﻘﻴــﺎم ﺑﻌﻤــﻞ ﴎﻳــﻊ ﻟﺘﻮﺻﻴﻒ اﻟﻌﺪﻳﺪ ﻣﻦ ﻣﺠﺮات CEERS ، ووﺿﻊ ﻧﻤﺎذج ﻫﻨﺪﺳﻴﺔ ﺛﻼﺛﻴﺔ اﻷﺑﻌﺎد ﻟﻬﺎ . ﻳﻘﻮل ﺑﺎﻧﺪﻳﺎ أﻳﻀًﺎ إن ﻋﻤﻠﻬﻢ ﻟﻢ ﻳﻜـﻦ ﻣﻤﻜﻨًـﺎ ﻟﻮﻻ اﻷﺑﺤﺎث ا ﻜﺜﻔﺔ اﻟﺘﻲ أﺟﺮاﻫﺎ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﺑﺎﺳﺘﺨﺪام ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﻔﻀـﺎﺋﻲ اﻟﺘـﺎﺑﻊ ﻟﻨﺎﺳﺎ . ﻟﻌﻘﻮد ﻣﻦ اﻟﺰﻣﻦ أﺑﻬﺮﻧﺎ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ ﺑﺼﻮر ﻟﺒﻌﺾ ا ﺠـﺮات اﻷوﱃ، ﺑـﺪءاً ﻣـﻦ أول اﻟﺤﻘـﻞ " ﺻﻮرة اﻟ " ﻌﻤﻴـﻖ ﻟـﻪ ﰲ ﻋـﺎ م 1995 واﺳﺘﻤﺮاراً ﰲ ا ﺴـﺢ اﻟﺮاﺋـﺪ ا ﻌـﺮوف ﺑﺎﺳـﻢ ا ﺴﺢ اﻟﻜﻮﻧﻲ ﻟﻠﱰاث اﻟﻌﻤﻴﻖ ﺧﺎرج ا ﺠـﺮات اﻟﻘﺮﻳـﺐ ﻣـﻦ اﻷ ﺷـﻌﺔ ﺗﺤــﺖ اﻟﺤﻤـﺮاء . أدت ﻣﺴـﻮﺣﺎت اﻟﺴـﻤﺎء اﻟﻌﻤﻴﻘـﺔ ﻣﺜـﻞ ﻫـﺬه إﱃ إﺣﺼﺎﺋﻴﺎت أﻛﱪ ﺑﻜﺜ ، ﻣﻤﺎ دﻓﻊ ﻋﻠﻤﺎء اﻟﻔﻠﻚ إﱃ إﻧﺸﺎء ﻧﻤﺎذج ﺛﻼﺛﻴﺔ اﻷﺑﻌﺎد ﻗﻮﻳﺔ ﻟﻠﻤﺠﺮات اﻟﺒﻌﻴﺪة ﻋﲆ ﻣﺪار اﻟﺰﻣﻦ اﻟﻜﻮﻧﻲ واﻟﻴﻮم ﻳﺴﺎﻋﺪ ﺗﻠﺴﻜﻮب وﻳﺐ ﰲ ﺗﻌﺰﻳﺰ ﻫﺬه اﻟﺠﻬﻮد، ﻣﻀﻴﻔًﺎ ﻣﺠﻤﻮﻋﺔ ﻛﺒ ة ﻣﻦ ا ﺠﺮات اﻟﺒﻌﻴﺪة اﻟﺘﻲ ﺗﻘﻊ ﺑﻌﻴﺪًا ﻋﻦ ﻣﺘﻨﺎول ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ وﻳﻜﺸﻒ ﻋﻦ اﻟﻜﻮن ا ﺒﻜﺮ ﺑﺘﻔﺎﺻﻴﻞ أﻛﱪ ﺑﻜﺜ ﻣﻤـﺎ ﻛـﺎن ﻣﻤﻜﻨًﺎ ﰲ اﻟﺴﺎﺑﻖ . ﻟﻘﺪ ﻛﺎﻧﺖ اﻟﺼﻮر اﻟﺘﻲ اﻟﺘﻘﻄﻬﺎ وﻳﺐ ﻟﻠﻜـﻮن ا ﺒﻜﺮ ﺑﻤﺜﺎﺑﺔ أﻣﻮاج ﻣﺤﻴﻄﻴﺔ ﺗﻘـﺪم ﻣﻮﺟـﺎت ﺟﺪﻳﺪة ﻣﻦ اﻷدﻟﺔ . أ وﺿﺢ ا ﺆﻟﻒ ا ﺸﺎرك ﻣﺎرك ﻫﻮﻳﺮﺗﺎس وﻫـﻮ ﻋﺎﻟﻢ أﺑﺤﺎث ﰲ ﻣﻌﻬﺪ اﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ ﰲ ﺟﺰر اﻟﻜﻨﺎري " : ﻟﻘﺪ أﻇﻬﺮ ﻫﺎﺑﻞ ﻣﻨﺬ ﻓـﱰة ﻃﻮﻳﻠـﺔ وﺟﻮد ﻓﺎﺋﺾ ﻣﻦ ا ﺠﺮات ا ﺴﺘﻄﻴﻠﺔ ." ﻟﻜﻦ اﻟﺒﺎﺣﺜ ﻣﺎ زاﻟﻮا ﻳﺘﺴﺎءﻟﻮن : ﻫﻞ ﺳﺘﻈﻬﺮ اﻟﺘﻔﺎﺻــﻴﻞ اﻹﺿ ـﺎﻓﻴﺔ ﺑﺸ ـﻜﻞ أﻓﻀ ـﻞ ﻣ ـﻊ اﻟﺤﺴﺎﺳـﻴﺔ ﻟﻠﻀـﻮء ﺗﺤــﺖ اﻷﺣﻤــﺮ؟ وأﻛ ـﺪ ﺗﻠﺴﻜﻮب وﻳﺐ أن ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ ﻟﻢ ﻳﻔﻮت أي ﻣﻴﺰات ﰲ ا ﺠﺮات اﻟﺘﻲ رﺻﺪﻫﺎ ﻛﻼﻫﻤﺎ . ﺑﺎﻹﺿﺎﻓﺔ إﱃ ذﻟﻚ أﻇﻬﺮ ﻟﻨـﺎ ﺗﻠﺴـﻜﻮب وﻳـﺐ اﻟﻌﺪﻳﺪ ﻣـﻦ ا ﺠـﺮات اﻟﺒﻌﻴـﺪة ذات اﻷﺷـﻜﺎل ا ﺘﺸﺎﺑﻬﺔ، وﻛﻠﻬﺎ ﺑﺘﻔﺼﻴﻞ ﻛﺒ . ﻻ ﺗﺰال ﻫﻨﺎك ﻓﺠﻮات ﰲ ﻣﻌﺮﻓﺘﻨﺎ ﻓﺎﻟﺒﺎﺣﺜﻮن ﻻ ﻳﺤﺘﺎﺟﻮن ﻓﻘﻂ إﱃ ﺣﺠﻢ ﻋﻴﻨﺔ أﻛﱪ ﻣﻦ وﻳـﺐ ﻟﺘﺤﺴــ اﻟﺨﺼــﺎﺋﺺ وا ﻮاﻗــﻊ اﻟﺪﻗﻴﻘــﺔ ﻟﻠﻤﺠﺮات اﻟﺒﻌﻴﺪة، ﺑﻞ ﺳـﻴﺤﺘﺎﺟﻮن أﻳﻀًـﺎ إﱃ ﻗﻀ ـﺎء وﻗ ـﺖ ﻃﻮﻳ ـﻞ ﰲ اﻟﺘﻐﻴ ـ واﻟﺘﺒ ـﺪﻳﻞ وﺗﺤــﺪﻳﺚ ﻧﻤـﺎذﺟ ﻬﻢ ﺣﺘـﻰ ﺗـﺘﻤﻜﻦ ﻣـﻦ أن ﺗﻌﻜﺲ ﺑﺸـﻜﻞ أﻓﻀـﻞ اﻷﺷـﻜﺎل اﻟﻬﻨﺪﺳـﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻟﻠﻤﺠﺮات اﻟﺒﻌﻴﺪة . ﻗﺎﻟﺖ ا ﺆﻟﻔﺔ ا ﺸـﺎرﻛﺔ إﻟﻴﺰاﺑﻴـﺚ ﻣـﺎﻛﺠﺮاث اﻷﺳﺘﺎذة ا ﺴﺎﻋﺪة ﰲ ﻛﻠﻴﺔ ﻛﻮﻟﺒﻲ ﰲ واﺗﺮﻓﻴـﻞ ﺑﻮﻻﻳﺔ ﻣ " : ﻫﺬه ﻧﺘﺎﺋﺞ ﻣﺒﻜﺮة ." ﻋﻤﻮﻣﺎ ﻧﺤﻦ ﺑﺤﺎﺟﺔ إﱃ اﻟﺘﻌﻤﻖ ﺑﺸﻜﻞ اﻛﱪ ﰲ اﻟﺒﻴﺎﻧﺎت ا ﺘﻮﻓﺮة ﻌﺮﻓـﺔ ﻣـﺎ ﻳﺤـﺪث ﺑﺸـﻜﻞ أﻓﻀــﻞ وﻟﻜﻨﻨــﺎ ﻣﺘﺤﻤﺴــ ﻮن ﺟــﺪًا ﻟﻬــﺬه اﻻﺗﺠﺎﻫﺎت ا ﺒﻜﺮة . - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 4