Free Astronomy Magazine November-December 2023 ARABIC VERSION

23 participated in the study. It is not clear how early in the life- time of the Universe, and how quickly, mag- netic fields in galaxies form because so far astronomers have only mapped magnetic fields in galaxies close to us. Now, using ALMA, in which the European Southern Observatory (ESO) is a partner, Geach and his team have discovered a fully formed magnetic field in a distant gal- axy, similar in struc- ture to what is ob- served in nearby gal- axies. The field is about 1000 times weaker than the Earth’s magnetic field, but extends over more than 16,000 light- years. “This discovery gives us new clues as to how galactic-scale magnetic fields are formed,” ex- plains Geach. Observing a fully de- veloped magnetic field this early in the history of the Universe indicates that magnetic fields spanning en- tire galaxies can form rapidly while young galaxies are still growing. The team believes that intense star formation in the early Universe could have played a role in acceler- ating the development of the fields. Moreover, these fields can in turn influence how later genera- tions of stars will form. Co-author and ESO astronomer Rob Ivison says that the discovery opens up “a new window onto the inner workings of galaxies, because the magnetic fields are linked to the material that is forming new stars.” To make this detection, the team searched for light emitted by dust grains in a distant galaxy, 9io9. Galaxies are packed full of dust grains and when a magnetic field is present, the grains tend to align and the light they emit becomes polarised. This means that the light waves oscillate along a preferred direction rather than randomly. When ALMA detected and mapped a polarised signal coming from 9io9, the presence of a magnetic field in a very distant galaxy was confirmed for the first time. “No other telescope could have achieved this,” says Geach. The hope is that with this and future observations of distant magnetic fields the mystery of how these fun- damental galactic features form will begin to unravel.  NOVEMBER-DECEMBER 2023 ﺗُﻈﻬــــــــﺮﻫــــــــﺬﻩ اﻟﺼــــــــﻮرة اﺗﺠـــــــــﺎﻩ اﻟﻤﺠـــــــﺎل اﻟﻤﻐﻨﺎﻃ ﺴـــــــﻲﻓـــــــﻲ ـــــــﺪة اﻟﻤﺠـــــــﺮة اﻟ ﻌ 9io9 اﻟـــــــ ــــــﺎن ﻋﻤــــــﺮ ﺗﻈﻬــــــﺮﻫﻨــــــﺎ ﻋﻨــــــﺪﻣﺎ ــﻮن اﻟ 20٠% ﻓﻘــﻂﻣــﻦ ﻋﻤـــﺮﻩ اﻟـــــﺤﺎﻟﻲوﻫــــﻮ أ ﻌـــــﺪ اﻛﺘﺸـــــﺎف ﻟﻤﺠـــــــﺎلﻣﻐﻨﺎﻃ ﺴـــــــﻲﻟﻤﺠـــــــﺮة ﻋﻠﻰ اﻹﻃﻼق . ﺗـــﻢ إﺟــــﺮاء اﻷرﺻــــﺎد ﺎﺳـــﺘﺨﺪام ﻌـــــــــــــﺪ ﻣﺮﺻـــــــــــــﺪ أﻟﻤـــــــــــــﺎ واﻟـــــــــــــﺬ ا ﻟﻤﺮﺻـﺪ اﻷوروﺑــﻲاﻟــﺠﻨﻮﺑﻲ ـــــﮫ . ﺷـــــﺮ ًﺎ ﻓ ـــــﺎت ﺗﺘﻮاﻓـــــﻖﺣﺒﻴ ـــــــــــــــﺎراﻟﻤﻮﺟـــــــــــــــﻮدة ﺿـــــــــــــــﻤﻦ اﻟﻐ اﻟﻤﺠـــﺮة 9io9 إﻟـــﻰﺣـــﺪ ﻣـــﺎ ﻣـــﻊ اﻟﻤﺠـــــــــــــــــــــــــﺎل اﻟﻤﻐﻨﺎﻃ ﺴـــــــــــــــــــــــــﻲ ﻟﻠﻤﺠـــــﺮةوﻧﺘﻴﺠـــــﺔ ﻟﻬـــــﺬا ﻨ ﻌــــــﺚ ﻣﻨﻬـــــــﺎ ﺿـــــــﻮء ﻣﺴـــــــﺘﻘﻄﺐ ﻣﻤـــــــﺎ أن ﻣﻮﺟـــــــــــــــﺎت اﻟﻀـــــــــــــــﻮء ﻌـــــــــــــــ ﺗﺘــــــــــــــــــــــﺄرﺟﺢ وﻟــــــــــــــــــــــ ﺲ ﺸـــــــــــــــــــــــ ﻞ ﻋﺸـﻮاﺋﻲ . اﻛﺘﺸـﻒﻣﺮﺻــﺪ أﻟﻤــﺎ إﺷــــــــــــﺎرة اﻻﺳــــــــــــﺘﻘﻄﺎبﻫـــــــــــــﺬﻩ ﺗﻤﻜــﻦ ﻋﻠﻤــﺎء واﻟـ اﻟﻔﻠــﻚﻣــﻦ ﺧﻼﻟﻬــــــــــــﺎ ﻣــــــــــــﻦ ــــــــــــﺪ اﺗﺠــــــــــــﺎﻩ ﺗﺤﺪ اﻟﻤﺠـــــــــــــــــــــــــﺎل اﻟﻤﻐﻨﺎﻃ ﺴـــــــــــــــــــــــــﻲ ــﺔ اﻟﻤﻮﺿـﺢﻫﻨــﺎ ﺨﻄـﻮطﻣﻨﺤﻨ ــــــﺔ ﻋﻠـــــــﻰﺻـــــــﻮرة ﻣﺮﺻـــــــﺪ ﻣ اﻛ أﻟﻤـــــــــــــــــﺎ . اﻹﺷـــــــــــــــــﺎرة اﻟﻀــــــــــــــــــﻮﺋ ﺔ اﻟﻤﺴـــــــــﺘﻘﻄ ﺔ اﻟﻤﻨ ﻌﺜــــــــــﺔﻣــــــــــﻦ ــﺎراﻟﻤﺼــﻄﻒ اﻟﻐ ﻣﻐﻨﺎﻃ ﺴــ ﺎ ﻓـــــــﻲ 9io9 ـــــــﺔ وﻻ ﺎﻫﺘـــــــﺔ ﻟﻠﻐﺎ ﺗﻤﺜـــﻞﺳـــﻮى 1 % ﻣـــﻦ إ ﻤـــﺎﻟﻲ ﺳﻄﻮع اﻟﻤﺠﺮة ﻟـﺬﻟﻚ اﺳـﺘﺨﺪم ـــــــــــﺔ اﻟﻔﻠﻜﻴـــــــــــﻮنﻃﺮ ﻘـــــــــــﺔﻃﺒ ﻌ ــــــــــــــﺔ ﻟﻤﺴــــــــــــــﺎﻋﺪﺗﻬﻢﻓـــــــــــــــﻲ ذﻛ اﻟـــــﺤﺼﻮل ﻋﻠـــــﻰﻫــــﺬﻩ اﻟﻨﺘﻴﺠــــﺔ . ﻓﻘــﺪﺳــﺎﻋﺪ اﻟﻔﺮ ــﻖﺣﻘ ﻘــﺔ أن 9io9 ﻋﻠــﻰاﻟــﺮﻏﻢﻣـﻦ ﻌــﺪﻫﺎ اﻟﻜﺒ ﻋﻨﺎ ﻗﺪ ﺗﻢ ﺗﻀﺨ ﻤﻬﺎ ﻣـﻦ ـــــــــﺔ ﺗﻌـــــــــﺮف ﺎﺳـــــــــﻢ ﺧــــــــﻼل ﻋﻤﻠ ﻋﺪﺳـــــﺔ اﻟــــــﺠﺎذﺑ ﺔ . ﻳﺤـــــﺪثﻫـــــﺬا ـﺪو اﻟﻀـﻮء اﻟﻘـﺎدمﻣـﻦ ﻋﻨـﺪﻣﺎ ﻳ ﻣﺠـــــﺮة ـــــﺪة ﻤــــــﺎ ﻓـــــﻲﻫــــــﺬﻩ ﻌ اﻟــــــــــﺤﺎﻟﺔ 9io9 أﻛـــــــــ ﺳــــــــــﻄﻮﻋﺎً وﻣﺸــﻮﻫﺎً ﻋﻨـــﺪﻣﺎ ﻔﻌـــﻞ ﻨﺤــ ــــــــــــﺔﺟﺴــــــــــــﻢﻛﺒــــــــــــ ﺟـــــــــــــﺪًا ﺟﺎذﺑ ﻣﻮﺟﻮد أﻣﺎﻣﮫ . ﺗﻈﻬـــﺮﻫـــﺬﻩ اﻟﺼـــﻮرة ﺎﻷﺷـــﻌﺔ ﺗﺤـــﺖ اﻟــــ ﻤﺮاء اﻟﻤﺠـــﺮة 9io9 واﻟـــ ﺣﻮلﻣﺠ ﺗﻈﻬﺮﻫﻨﺎ ﻛﻘﻮسﻣ ﻤﺮﻣﻨﺤ ﺮة ﻗﺮ ﺔ ﻣﺸـﺮﻗﺔ وﺗﻌﻤـﻞ ــﺔ ـــﺔ ﻛﻌﺪﺳـــﺔﺟﺎذﺑ ﻫــﺬﻩ اﻟﻤﺠـــﺮة اﻟﻘﺮ : ـــﺚﺗﻌﻤـــﻞ ﻛﺘﻠﺘﻬـــﺎ ﻋﻠــﻰ ﺣ إﻟـــﻰاﻧﺤﻨـــﺎء اﻷﺷـــﻌﺔ اﻟﻀـــﻮﺋ ﺔ ـــﺎنﺣﻮﻟﻬـــﺎ ﻣﻤـــﺎ ﻳـــﺆد اﻧﺤﻨــﺎء اﻟﺰﻣ اﻟﻘﺎدﻣـﺔﻣـﻦ 9io9 ﺧﻠﻔﻬـﺎ وﻫـﺬا ﺳـ ﺐ ﺷـ ﻠﻬﺎ اﻟﻤﺸـﻮﻩ . إنﻫـﺬا ﺻـــــﻮراﻷﺷـــــﻌﺔ ﺗﺤـــــﺖ اﻟــــــ ﻤﺮاء اﻟﻌـــــﺮضاﻟﻤﻠـــــﻮن ﻧﺘﻴﺠــــﺔ ﻟﻠــــــ ﻤﻊ ﺑـــــ ﺑﻮاﺳـﻄﺔ ﺗﻠﺴـ ﻮب اﻟﻤﺴـﺢ اﻟﻤﺮ ـﻲواﻷﺷـﻌﺔ ﺗﺤــﺖ اﻟـــ ﻤﺮاء ﻟﻌﻠـﻢ اﻟﻔﻠــﻚ ) ( ﻓ ﺴــﺘﺎ اﻟﺘــﺎﺑﻊ ﻟﻠﻤﺮﺻـــﺪ اﻷوروﺑــﻲاﻟـــﺠﻨﻮﺑﻲﻓــﻲﺗﺸـــ ﻠﻲ اﻟﻔﺮﺴﻲﻓﻲاﻟﻮﻻ ﺎت اﻟﻤﺘﺤﺪة وﺗﻠﺴ ﻮبﻫﺎواياﻟﻜﻨﺪ . ﻟﻴﺲ ﻣﻦ اﻟﻮ اﺿﺢ ﰲ أي وﻗـﺖ ﻣﺒﻜﺮ ﻣﻦ ﻋﻤﺮ اﻟﻜﻮن أو ﻣـﺪى ﴎﻋ ــﺔ ﺗﺸ ــﻜﻞ ا ﺠـــﺎﻻت ا ﻐﻨﺎﻃﻴﺴ ـﻴﺔ ﰲ ا ﺠ ـﺮات ﻷن ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻟﻢ ﻳﺮﺳﻤﻮا ﺣﺘـﻰ اﻵن ﺳﻮى ﺧـﺮاﺋﻂ ﻟﻠﻤﺠـﺎﻻت ا ﻐﻨﺎﻃﻴﺴـــﻴﺔ ﰲ ا ﺠـــﺮات اﻟﻘﺮﻳﺒﺔ ﻣﻨﺎ واﻵن، وﺑ ﺎﺳﺘﺨﺪام ﻣﺮﺻﺪ أ ﺎ اﻟـﺬي ﻳﺸـﺎرك ﻓﻴـﻪ ا ﺮﺻ ـﺪ اﻷوروﺑ ـﻲ اﻟﺠﻨــﻮﺑﻲ اﻛﺘﺸﻒ ﻏﻴﺘﺶ وﻓﺮﻳﻘﻪ ﻣﺠﺎﻻً ﻣﻐﻨﺎﻃﻴﺴﻴًﺎ ﻣﻜﺘﻤـﻞ اﻟﺘﻜـﻮﻳﻦ ﰲ ﻣﺠﺮة ﺑﻌﻴﺪة ﻳﺸﺒﻪ ﰲ ﺑﻨﻴﺘـﻪ ﻣ ـﺎ ﻳ ـﺘﻢ رﺻـﺪه ﰲ ا ﺠ ـﺮات اﻟﻘﺮﻳﺒﺔ وﻫﺬا ا ﺠـﺎل أﺿـﻌﻒ ﺑﻨﺤﻮ 1000 ﻣﺮة ﻣـﻦ ا ﺠـﺎل ا ﻐﻨﺎﻃﻴﴘ ﻟﻸرض وﻟﻜﻨﻪ ﻳﻤﺘﺪ ﻋـﲆ أﻛﺜ ـﺮ ﻣ ـﻦ 1600 ﺔ ﺳـﻨ . " ﺿـــﻮﺋﻴﺔ ﻳﻌﻄﻴﻨـــﺎ ﻫـــﺬا اﻻﻛﺘﺸﺎف أدﻟﺔ ﺟﺪﻳـﺪة ﺣـﻮ ل ﻣﺪى ﺣﺠﻢ ا ﺠﺮة . ﻳﴩح ﻏﻴﺘﺶ " : ﻳﻌﻄﻴﻨـﺎ ﻫـﺬا اﻻﻛﺘﺸﺎف أدﻟﺔ ﺟﺪﻳـﺪة ﺣـﻮل ﻛﻴﻔﻴـــﺔ ﺗﺸـــﻜﻞ ا ﺠ ــﺎﻻت ا ﻐﻨﺎﻃﻴﺴــﻴﺔ ﻋــﲆ ﻧﻄــﺎق ﺔ ﺗﺸﻜﻞ ا ﺠـ ﺎﻻت ا ﻐﻨﺎﻃﻴﺴـﻴﺔ ﻋـﲆ ﻧﻄﺎق ا ﺠﺮ ". ة إن رﺻﺪ ﻣﺠﺎل ﻣﻐﻨﺎﻃﻴ ﴘ ـ ﻣﺘﻄﻮر ﺑﺎﻟﻜﺎﻣﻞ ﰲ وﻗﺖ ﻣﺒﻜﺮ ﻣـﻦ ﺗـﺎرﻳﺦ اﻟﻜﻮن ﻳﺸ إﱃ أن ا ﺠـﺎﻻت ا ﻐﻨﺎﻃﻴﺴـﻴﺔ اﻟﺘـﻲ ﺗﻐﻄـﻲ ﻣﺠـﺮات ﺑﺄﻛﻤﻠﻬـﺎ ﻳﻤﻜـﻦ أن ﺗﺘﺸﻜﻞ ﺑـ ـ ﴪﻋﺔ ﺑﻴﻨﻤـﺎ ﻻ ﺗـﺰال ا ﺠـﺮات اﻟﺸﺎﺑﺔ ﰲ ﻃﻮر اﻟﻨﻤـﻮ . ﻳﻌﺘﻘـﺪ اﻟﻔﺮﻳـﻖ أن ﺗﺸﻜﻞ اﻟﻨﺠﻮم ا ﻜﺜﻒ ﰲ ﺑﺪاﻳـﺔ اﻟﻜـﻮن ﻗـﺪ ﻟﻌﺐ دورًا ﰲ ﺗﴪ ﻳﻊ ﺗﻄﻮر ﻫـﺬه ا ﺠـﺎﻻت . ﻋﻼوة ﻋﲆ ذﻟﻚ، ﻳﻤﻜﻦ ﻟﻬﺬه ا ﺠﺎﻻت ﺑﺪورﻫﺎ أن ﺗﺆﺛﺮ ﻋﲆ ﻛﻴﻔﻴﺔ ﺗﺸﻜﻞ اﻷﺟﻴﺎل اﻟﻼﺣﻘـﺔ ﻣﻦ اﻟﻨﺠﻮم . ﻳﻘﻮل ا ﺆﻟـﻒ ا ﺸـﺎرك وﻋـﺎﻟﻢ اﻟﻔﻠﻚ روب اﻳﻔﻴﺴﻮن إ" : ن ﻫﺬا اﻻﻛﺘﺸـﺎف " ﻳﻔﺘﺢ ﻧﺎﻓﺬة ﺟﺪﻳ ﺪة ﻋﲆ اﻷﻋﻤﺎل اﻟﺪاﺧﻠﻴـﺔ ﻟﻠﻤﺠﺮات ﻷن ا ﺠﺎﻻت ا ﻐﻨﺎﻃﻴﺴﻴﺔ ﻣﺮﺗﺒﻄﺔ ﺑﺎ ﻮاد اﻟﺘﻲ ﺗﺸﻜﻞ ﻧﺠﻮﻣًﺎ ﺟﺪﻳﺪة ." وﻹﺟﺮاء ﻫﺬا اﻻﻛﺘﺸﺎف ﺑﺤﺚ اﻟﻔﺮﻳـﻖ ﻋـﻦ اﻟﻀﻮء ا ﻨﺒﻌﺚ ﻣﻦ ﺣﺒﻴﺒﺎت اﻟﻐﺒﺎر ﰲ ا ﺠﺮة اﻟ ﺒﻌﻴﺪة، 9io9 . ﺗﻤﺘﻠـﺊ ا ﺠـﺮات ﺑﺤﺒﻴﺒـﺎت اﻟﻐﺒﺎر وﻋﻨﺪﻣﺎ ﻳﻮﺟـﺪ ﻣﺠـﺎل ﻣﻐﻨﺎﻃـ ﻴﴘ ـ ﺗﻤﻴـﻞ اﻟﺤﺒﻴﺒـﺎت إﱃ اﻻﺻـﻄﻔﺎف وﻳ ﺼـﺒﺢ اﻟﻀﻮء ا ﻨﺒﻌﺚ ﻣﻨﻬﺎ ﻣﺴﺘﻘﻄﺒًﺎ وﻫﺬا ﻳﻌﻨـﻲ أن ﻣﻮﺟـﺎت اﻟﻀـﻮء ﻟـﻦ ﺗﺘـﺄرﺟﺢ ﺑﺸـﻜﻞ . ﻋﺸﻮاﺋﻲ ﻋﻨﺪﻣﺎ اﻛﺘﺸﻒ ﻣﺮﺻﺪ أ ﺎ ورﺳﻤﺖ إﺷﺎرة ﻣﺴﺘﻘﻄﺒﺔ ﻗﺎدﻣﺔ ﻣﻦ ا ﺠﺮة 9io9 ﺗﻢ ﺗﺄﻛﻴﺪ وﺟﻮد ﻣﺠﺎل ﻣﻐﻨﺎﻃـ ـ ﻴﴘ ﰲ ﻣﺠـﺮة ﺑﻌﻴﺪة ﺟﺪ اً . ﻷول ﻣﺮة ﻳﻘﻮل ﻏﻴﺘﺶ " : ﻟﻢ ﻳﻜﻦ ﺑﻤﻘﺪور أي ﺗﻠﺴﻜﻮب آﺧﺮ ﺗﺤﻘﻴﻖ ذﻟﻚ ." إن اﻷﻣـﻞ ﻫـﻮ أﻧـﻪ ﻣـﻊ اﻷرﺻـﺎد اﻟﺤﺎﻟﻴـﺔ ا ﺴﺘﻘﺒﻠ و ﻴﺔ ﻟﻠﻤﺠﺎﻻت ا ﻐﻨﺎﻃﻴﺴﻴﺔ اﻟﺒﻌﻴﺪة ﻛﺸﻒ ﺳﻴﺒﺪأ ﻏﻤﻮض ﻛﻴﻔﻴـﺔ ﺗﺸـﻜﻞ ﻫـﺬه اﻟﺴﻤﺎت ا ﺠﺮﻳﺔ اﻷﺳﺎﺳﻴﺔ . ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 23 ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 3