Free Astronomy Magazine January-February 2024 ARABIC VERSION

Furthermore, nearly all the candi- dates were near to massive galaxies, suggesting that their local environ- ment plays an important role in their formation. “Once we analyzed the Gemini ob- servations and eliminated all the background contamination, we could see that these transition galaxies existed almost exclusively near the largest galaxies. We imme- diately knew that environmental transformation had to be impor- tant,” said Kaixiang Wang, a PhD student at Peking University and lead author of the paper. Besides identifying the environment UCDs live in, these results also lend valuable insight into how many of these objects there are and what the full sequence of their evolution- ary change looks like. “It’s exciting that we can finally see this transfor- mation in action,” said Peng. “It tells us that many of these UCDs are visible fossil remnants of ancient dwarf galaxies in galaxy clusters, and our results suggest that there are likely many more low-mass rem- nants to be found,” he added. “This study illustrates how large sur- veys can improve our understanding of the biggest questions in astron- omy, like galaxy evolution,” says Chris Davis, NSF Program Director for NOIRLab. “NSF’s NOIRLab is a world leader in supporting astro- nomical surveys and — importantly — providing community and public access to the data and the amazing resulting discoveries.”     ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 33 - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 4 ﺳﻠﺴــــﻠﺔ ﺗــــﻢ ﻣﺘﻮاﺻــــﻠﺔ ﻣــــﻦ اﻟﻤﺠــــﺮات اﻟــــ اﻟﺘﻘﺎﻃﻬـــــﺎ ﻓـــــﻲﻣﺮاﺣـــــﻞ ﻣﺨﺘﻠﻔـــــﺔ ـــــﺔ ﻣـــــﻦ ﻋﻤﻠ اﻟﺘﺤـــــﻮل ﻣـــــﻦ ﻣﺠـــــﺮة ﻗﺰﻣـــــﺔ إﻟـــــﻰﻣﺠـــــﺮة ﻗﺰﻣـــــﺔ ﻓﺎﺋﻘﺔ اﻟﺼﻐﺮ و ﺗﻘﻊ ﻫﺬﻩ اﻷﺟـ ﺮام ـﺎﻟﻘﺮ ﻣـﻦ ــــــﺔ اﻟﻌﻤﻼﻗــــــﺔ اﻟﻤﺠــــــﺮة اﻹﻫﻠ ﻠﺠ M87 وﻫــــــﻲ اﻟﻌﻀﻮ اﻟﻤﻬ ﻤﻦ ﻓﻲﻋﻨﻘﻮد اﻟﻌﺬراء . ذﻟﻚ ﻋﻼوة ﻋﲆ ﻛﺎﻧﺖﺟﻤﻴﻊ ا ﺠﺮات ا ﺮﺷﺤﺔ ﺗﻘﺮﻳﺒًﺎ ﻗﺮﻳﺒﺔ ﻣﻦ ا ﺠـﺮات اﻟﻀـﺨﻤﺔ، ﻣﻤـﺎ ﻳﺸ إﱃ أن ﺑﻴﺌﺘﻬﺎ ا ﺤﻠﻴﺔ ﺗﻠﻌﺐ دور ﰲ ﺎً ﻣﻬﻤ اً ﺗﻜﻮﻳﻨﻬﺎ " . ﺑﻤﺠﺮد أن ﻗﻤﻨـﺎ ﺑﺘﺤﻠﻴـﻞ أرﺻـﺎد ﺗﻠﺴﻜﻮب ﺟﻴﻤﻴﻨﻲ و اﻟﻘﻀﺎء ﻋﲆ ﻛﻞ اﻟﺘﻠـﻮث ﰲ اﻟﺨﻠﻔﻴﺔ ﻳﻤﻜﻨﻨﺎ أن ﻧﺮى أن ﻫـﺬه ا ﺠـﺮات اﻻﻧﺘﻘﺎﻟﻴﺔ ﻛﺎﻧﺖ ﻣﻮﺟﻮدة ﺑﺸـﻜﻞ ﺣـ ﴫي ـ ﺎً ﺗﻘﺮﻳﺒ ﺑـﺎﻟﻘﺮب ﻣـﻦ ا ﺠـﺮات اﻷﻛـﱪ . ﻗـﺎل ﻛﺎﻳﺸﻴﻨﻎ واﻧﻎ ﻃﺎﻟﺐ اﻟـﺪﻛﺘﻮراه ﰲ ﺟﺎﻣﻌـﺔ ﺑﻜ وا ﺆﻟﻒ اﻟﺮﺋﻴﴘ ﻟﻠﺪراﺳﺔ " : ﻟﻘﺪ أدرﻛﻨﺎ ﻋﲆ اﻟﻔﻮر أ ن اﻟﺘﺤﻮل اﻟﺒﻴﺌﻲ ﻳﺠﺐ أن ﻳﻜـﻮن ﺎً ﻣﻬﻤ إﱃ ﺟﺎﻧﺐ ﺗ ﺤﺪﻳﺪ اﻟﺒﻴﺌـﺔ اﻟﺘـﻲ ﺗﻌـﻴﺶ ﻓﻴﻬﺎ اﻟﻜﺎﺋﻨﺎت ﻏ ا ﻜﺘ ﻤﻠﺔ اﻟﻨﻤﻮ، ﺗﻮﻓﺮ ﻫﺬه اﻟﻨﺘﺎﺋﺞ أﻳﻀ ﺎً ﻧﻈﺮة ﺛﺎﻗﺒﺔ ﺣـﻮل ﻋـﺪد ﻫـﺬه اﻷﺟـﺮام ا ﻮﺟـﻮدة وﻛﻴـﻒ ﻳﺒـﺪو اﻟﺘﺴﻠﺴـﻞ اﻟﻜﺎﻣﻞ ﻟﺘﻐ ﻫﺎ اﻟﺘﻄﻮري ﻗـﺎ . : " ل ﺑﻨـﻎ ﻣـﻦ ا ﺜ أن ﻧﺘﻤﻜﻦ أﺧ اً ﻣﻦ رؤﻳﺔ ﻫﺬا اﻟﺘﺤـﻮل " ﻋﻤﻠﻴًﺎ وأﺿﺎف " : ﻳﺨﱪﻧﺎ ذﻟﻚ أن اﻟﻌﺪﻳﺪ ﻣـﻦ ﻫﺬه اﻟﺤﻔﺮﻳـﺎت ﻏـ ا ﻜﺘﻤﻠـﺔ ﻫـﻲ ﺑﻘﺎﻳـﺎ أﺣﻔﻮرﻳﺔ ﻣﺮﺋﻴﺔ ﻟﻠﻤﺠﺮات اﻟﻘﺰﻣﺔ اﻟﻘﺪﻳﻤﺔ ﰲ ﻣﺠﻤﻮﻋﺎت ا ﺠﺮات، وﺗﺸ ﻧﺘﺎﺋﺠﻨـﺎ إﱃ أﻧـﻪ ﻋﻨﺎﻗﻴﺪ ا ﺠﺮات وﺗﺸ ﻧﺘﺎﺋﺠﻨـﺎ إﱃ أﻧـﻪ ﻣـﻦ ا ﺤﺘﻤﻞ أن ﻳﻜﻮن ﻫﻨﺎك اﻟﻌﺪﻳـﺪ ﻣـﻦ اﻟﺒﻘﺎﻳـﺎ ﻣﻨﺨﻔﻀﺔ اﻟﻜﺘﻠﺔ اﻟﺘﻲ ﻳﻤ ﻜﻦ اﻟﻌﺜﻮر ﻋﻠﻴﻬﺎ ". ﻳﻘﻮل ﻛﺮﻳﺲ دﻳﻔﻴﺲ ﻣﺪﻳﺮ ﺑﺮﻧﺎﻣﺞ ﻣﺆﺳﺴﺔ اﻟﻌﻠﻮم اﻟﻮﻃﻨﻴﺔ ﰲ ﻣﺨﺘﱪ ﻧﻮﻳﺮﻻب " : ﺗﻮﺿـﺢ ﻫﺬه اﻟﺪراﺳﺔ ﻛﻴﻒ ﻳﻤﻜﻦ ﻟﻠﻤﺴﻮﺣﺎت اﻟﻜﺒ ة أن ﺗﺤﺴﻦ ﻓ ﻬﻤﻨﺎ ﻷﻛﱪ اﻷﺳﺌﻠﺔ ﰲ ﻋﻠﻢ اﻟﻔﻠـﻚ ﻣﺜﻞ ﺗﻄﻮر ا ﺠﺮات إن ". " ﻣﺨﺘـﱪ ﻧـﻮﻳﺮﻻب اﻟﺘﺎﺑﻊ ﺆﺳﺴﺔ اﻟﻌﻠـﻮم اﻟﻮﻃﻨﻴـﺔ ﻫـﻮ راﺋـﺪ ﻋﺎ ﻲ ﰲ دﻋﻢ ا ﺴﻮﺣﺎت اﻟﻔﻠﻜﻴﺔ واﻷﻫﻢ ﻣـﻦ ذﻟﻚ ﺗﻮﻓ وﺻـﻮل ا ﺠﺘﻤـﻊ واﻟﺠﻤﻬـﻮر إﱃ اﻟﺒﻴﺎﻧ ﺎت واﻻﻛﺘﺸﺎﻓﺎت ا ﺬﻫﻠﺔ ." [NOIRLab/NSF/AURA/NASA/R. Gendler/ K. Wang/M. Zamani]