Free Astronomy Magazine May-June 2024 ARABIC VERSION

Uncovering the origin of the rare radio circles by W. M. Keck Observatory Michelle Franklin − UC San Diego t’s not every day astronomers say, “What is that?” After all, most ob- servedastronomicalphenomenaarekn own:stars,planets,blackholes and galaxies. But in 2019 the newly completed ASKAP (Australian Square KilometerArrayPathfinder)tele- scope picked up something no one hadeverseenbefore:radiowavecir- cles so large they contained entire galaxies in their centers. As the astrophysics community tried todeterminewhatthesecircleswere, theyalsowantedtoknowwhythe circleswere.NowateamledbyUni- versity of California San Diego Pro- fessor of Astronomy and Astro- physicsAlisonCoilbelievestheymay have found the answer: the circles areshellsformedbyoutflowingga- lacticwinds,possiblyfrommassive ﺗﺤﺪ ﺪ أﺻﻞ اﻟﺪواﺋﺮاﻟﺮادﻳﻮ ﺔ اﻟﻨﺎدرة : ﻘﻠﻢ ﻣﺮﺻﺪ د ﻠﻴﻮ ﻛ ﻚ. إم. ﻣ ﺸﻴﻞ ﻓﺮاﻧ ﻠ - ﺟﺎﻣﻌﺔ ﺎﻟ ﻔﻮر ﺎ ﻓﻲﺳﺎن دﻳ ﻐﻮ - ﻣﺎﻳﻮ ﻳﻮﻧﻴﻮ 2 0 2 4 ﻋﻠﻤـﺎء اﻟﻔﻠﻚ ﻻ ﻳﺘﺴﺎﺋﻠﻮن ﻛﻞ ﻳـﻮم ﻓ ﻤﻌﻈـﻢ اﻟﻈﻮاﻫﺮ اﻟﻔﻠﻜﻴﺔ ا ﺮﺻﻮدة ﻣﻌﺮوﻓﺔ : اﻟﻨﺠـﻮم وا ﻟﻜﻮاﻛﺐ واﻟﺜﻘﻮب اﻟﺴﻮداء وا ﺠﺮات ﻟﻜﻦ ﰲ ﻋــﺎم 2019 اﻟــﺘﻘﻂ ﺗﻠﺴــﻜﻮب أﺳــﻜﺎب ) ﻣﺼﻔﻮﻓﺔ اﻟﻜﻴﻠﻮﻣﱰ ا ﺮﺑﻊ اﻷﺳﱰاﱄ ( ا ﻜﺘﻤﻞ ﺣﺪﻳﺜًﺎً ﺷﻴﺌًﺎً ﻟـﻢ ﻳـﺮه أﺣـﺪ ﻣـﻦ ﻗﺒـﻞ : دواﺋـﺮ رادﻳﻮﻳﺔ ﻣﻮﺟﺎت رادﻳﻮﻳﺔ اً ﻛﺒ ة ﺟﺪ ﺑﺤﻴﺚ ﺗ ﺤﺘﻮي ﻋﲆ ﻣﺠـﺮات ﻛﺎﻣﻠ ـﺔ ﰲ ﻣﺮاﻛﺰﻫـﺎ وﺑﻴﻨﻤ ـﺎ ﻛ ـﺎن ﻣﺠﺘﻤـﻊ اﻟﻔﻴﺰﻳـﺎء اﻟﻔﻠﻜﻴــ ﺔ ﻳﺤـﺎول ﺗﺤﺪﻳـﺪ ﻣﺎﻫﻴﺔ ﻫﺬه ا ﻟﺪواﺋﺮ أرادوا أﻳﻀ ﺎً ﻣﻌﺮﻓﺔ ﺳـﺒﺐ وﺟﻮد ﻫﺬه اﻟﺪواﺋﺮ . ﻳﻌﺘ ﻘﺪ اﻵن ﻓﺮﻳﻖ ﺑﻘﻴﺎدة أﻟﻴ ـ ﺴﻮن ﻛﻮﻳﻞ أﺳﺘﺎذ ﻋﻠ ـﻢ اﻟﻔﻠ ـﻚ واﻟﻔﻴﺰﻳ ـﺎء اﻟﻔﻠﻜﻴ ـﺔ ﺑﺠﺎﻣﻌ ـﺔ ﻛﺎﻟﻴﻔﻮرﻧﻴﺎ ﰲ ﺳﺎن دﻳﻴﻐﻮ أﻧﻬﻢ رﺑﻤﺎ ﻗﺪ وﺟﺪوا اﻹﺟﺎﺑﺔ ﻋﲆ ﻫﺬا ا ﻟﺴﺆال : اﻟﺪواﺋﺮ ﻋﺒﺎرة ﻋﻦ أﻏﻠﻔﺔ ﺗﺸﻜ ﻠﺖ ﺑﻔﻌﻞ اﻟﺮﻳﺎح ا ﺠﺮﻳﺔ ا ﺘﺪﻓﻘﺔ و رﺑﻤﺎ ﻣﻦ اﻟﻨﺠﻮم ا ﺘﻔﺠـﺮة اﻟﻀﺨﻤﺔ ا ﻌﺮوﻓﺔ ﺑﺎﺳﻢ ا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ .