Free Astronomy Magazine July-August 2024 ARABIC VERSION

23 n 2022 scientists un- veiled the first image of Sgr A* at press con- ferences around the world, including at the European Southern Ob- servatory (ESO). While the Milky Way’s super- massive black hole, which is roughly 27,000 light-years away from Earth, is more than a thousand times smaller and less massive than M87’s, the first-ever black hole imaged, the observations revealed that the two look re- markably similar. This made scientists won- der whether the two shared common traits outside of their looks. To find out, the team decided to study Sgr A* in polarised light. Pre- vious studies of light around the M87 black hole (M87*) revealed that the magnetic fields around it allowed the black hole to launch powerful jets of material back into the surrounding environment. Build- ing on this work, the new images have revealed that the same may be true for Sgr A*. “What we’re seeing now is that there are strong, twisted, and or- ganised magnetic fields near the black hole at the centre of the Milky Way galaxy,” said Sara Issaoun, NASA Hubble Fellowship Program Einstein Fellow at the Center for As- trophysics | Harvard & Smithsonian, US, and co-lead of the project. “Along with Sgr A* having a strik- ingly similar polarisation structure to that seen in the much larger and more powerful M87* black hole, we’ve learned that strong and or- dered magnetic fields are critical to how black holes interact with the gas and matter around them.” JULY-AUGUST 2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ ُ ﻈﻬـــــﺮ ﻫــــــﺬا اﻟﻤﻨﻈــــــﺮذو اﻟﻀـــــﻮء اﻟﻤﺮــــــﻲواﺳـــــﻊ اﻟﻤﺠــــــﺎل اﻟﺴــــــﺤﺐ اﻟﻨ ﻤ ﺔ اﻟﻐﻨ ﺔ ﻓﻲ ﻮﻛ ﺔ اﻟﻘﻮس ) راﻣﻲ اﻟﺴﻬﺎم ( ﻓـﻲ اﺗﺠـﺎﻩ ﻣﺮﻛـﺰ ﻣﺠﺮ ﻨﺎ در اﻟﺘ ﺎﻧﺔ . ﺗﻤﺘﻠﺊ اﻟﺼﻮ رة ﺄ ﻤﻠﻬـﺎ ﺄﻋـﺪاد ﻫﺎﺋﻠـﺔ ﻣـﻦ اﻟﻨﺠـﻮم وﻟﻜــﻦ ﻈــﻞ ﻋــﺪد أﻛــ ﻜﺜــ ﻣﻨﻬــﺎ ــﺎً ﻣﺨﺘﻔ ــﺘﻢ ــﺎر وﻻ ﺧﻠــﻒﺳــﺤﺐ اﻟﻐ اﻟﻜﺸﻒﻋﻨﮫ إﻻ ﻓﻲﺻﻮر اﻷﺷﻌﺔ ﺗﺤﺖ اﻟ ـ . ﻤﺮاء ﺗﻢ إﻧﺸﺎء ﻫﺬا اﻟﻤﻨﻈﺮ ـﺔ ﺎﻟﻀـﻮء اﻷ ﻤـﺮواﻷزرق و ﺸـ ﻞ ﺟـﺰءًا ﻣـﻦ ﻣﺴـﺢ ﻣﻦ ﺻﻮر ﻓﻮﺗﻮﻏﺮاﻓ اﻟﺴﻤﺎء اﻟﺮﻗﻤﻲ 2 . وﻳ ﻠﻎ ﻣﺠﺎل اﻟﺮؤ ﺔ ﺣﻮاﻟﻲ 3.5 درﺟﺔ ×3.6 . درﺟﺔ اﻟــﺘﻘﻂ ﻓﺮ ــﻖ ﺗﻠﺴــ ﻮب ا ﻔ ﻨــﺖ ﻫــﻮراﻳﺰون أﻧــﺘﺞ أول ﺻــﻮرة ﻋﻠــﻰ اﻹﻃــﻼق ﻟﺜﻘ ﻨــﺎ اﻷﺳــﻮد ﻓــﻲدر اﻟــﺬ ﺗــﻢ إﺻــﺪارﻫﺎ ﻓـﻲﻋــﺎم اﻟﺘ ﺎﻧـﺔ واﻟـ 2022 ـﺪة ﻟﻠﺠﺴـﻢ اﻟﻀــ ﻢ اﻟﻤﻮﺟــﻮد ﻓـﻲﻣﺮﻛـﺰﻣﺠﺮﻨــﺎ ــﺔ ﺟﺪ رؤ : ــﻒ ﻛ ــــﺪو ﻓــــﻲ اﻟﻀــــﻮء اﻟﻤﺴــــﺘﻘﻄﺐ ﻳ . ـــــﺎس ــــﺘﻤﻜﻦ ﻓﻴﻬــــﺎ ﻋﻠﻤــــﺎء اﻟﻔﻠــــﻚ ﻣــــﻦ ﻗ ﻫــــﺬﻩ ﻫــــﻲ اﻟﻤــــﺮة اﻷوﻟـــــﻰ اﻟــــ ــﺎﻟﻘﺮ ﻣـــﻦ ﺣﺎﻓــﺔ ﺳــﺎﺟ ﺘﺎر ﻮس اﻻﺳــﺘﻘﻄﺎب وﻫــﻮ دﻻﻟــﺔ ﻋﻠـــﻰ اﻟﻤﺠــﺎﻻت اﻟﻤﻐﻨﺎﻃ ﺴــ ﺔ A .* ﺗُﻈﻬــﺮﻫـــﺬﻩ اﻟﺼـﻮرة اﻟﻤﻨﻈـﺮ اﻟﻤﺴـﺘﻘﻄﺐ ﻟﻠﺜﻘـﺐ اﻷﺳـﻮد ﻓـﻲ در اﻟﺘ ﺎﻧـﺔ . ﺗﺸـ اﻟـ ـ ـﺔ ﻓـﻲﻫـﺬﻩ اﻟﺼـﻮرة ﺨﻄﻮط اﻟﻤ اﻛ إﻟﻰ اﺗﺠﺎﻩ اﻻﺳﺘﻘﻄﺎب اﻟﻤﺮ ﻂ ﺎﻟﻤﺠﺎل اﻟﻤﻐﻨﺎﻃ ﺴﻲﺣﻮل ﻇﻞ اﻟﺜﻘﺐ اﻷﺳﻮد ] . Collabration EHT [ ﻛﺸـﻒ اﻟﻌﻠﻤﺎء ﻋﺎم 2022 ﻋﻦ اﻟﺼـﻮرة اﻷوﱃ ﻟﻠﺜﻘـﺐ اﻷﺳﻮد ﺳـﺎﺟﻴﺘﺎرﻳﻮس A * ﰲ ﻣﺆﺗﻤﺮات ﺻﺤﻔﻴﺔ ﺣـﻮل اﻟﻌﺎﻟﻢ ﺑﻤﺎ ﰲ ذﻟﻚ ﰲ ا ﺮﺻـﺪ اﻟﺠﻨﻮﺑﻲ اﻷوروﺑـﻲ ﰲ ﺣـ أن اﻟﺜﻘﺐ اﻷﺳﻮ د اﻟﻬﺎﺋـﻞ ﰲ ﻣﺠﺮة درب اﻟﺘﺒﺎﻧـﺔ واﻟـﺬي ﻳﺒﻌﺪ ﺣﻮاﱄ 27 أﻟـﻒ ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻋـﻦ اﻷرض أﺻـﻐﺮ ﺑﺄﻟﻒ ﻣﺮة وأﻗـﻞ ﻛﺘﻠـﺔ ﻣـﻦ اﻟﺜﻘ ـــﺐ اﻷﺳ ـــﻮد M87 ) ا ﻮﺟـﻮد ﰲ ا ﺠـﺮة M87 ( وﻫﻮ أول ﺛﻘـﺐ أﺳـﻮد ﻳـﺘﻢ ﺗﺼــﻮﻳﺮه ﻓﻘــﺪ ﻛﺸــﻔﺖ اﻷرﺻﺎد أن اﻻﺛﻨـ ﻳﺒـﺪوا ن ﻣﺨﺘﻠﻔــــ إﻻ أﻧﻬﻤــــﺎ ﺎن ﻣﺘﺸﺎﺑﻬ ﺑﺸﻜﻞ ﻣﻠﺤـﻮظ ﻣﺎ ﺟﻌﻞ اﻟﻌﻠ ﻤﺎء ﻳﺘﺴﺎءﻟﻮن إذا ﻛﺎن اﻻﺛﻨﺎن ﻳﺸﱰﻛﺎن ﰲ ﺳﻤﺎت ﺧـﺎرج ﻣﻈﻬﺮﻫﻤـﺎ . ﻌﺮﻓـﺔ ذﻟـﻚ ﻗـﺮر اﻟﻔﺮﻳـﻖ دراﺳﺔ ﺳـﺎﺟﻴﺘﺎرﻳﻮس A * ﻋــﱪ اﻟﻀــﻮء ا ﺴــﺘﻘﻄﺐ وﻛﺸﻔﺖ اﻟﺪراﺳﺎت اﻟﺴﺎﺑﻘﺔ ﻟﻠﻀﻮء ﺣﻮل اﻟﺜﻘﺐ اﻷﺳـﻮد M87) أن*( ا ﺠــــــﺎﻻت ا ﻐﻨﺎﻃﻴﺴﻴﺔ ا ﺤﻴﻄـﺔ ﺑـﻪ ﺳــﻤﺤﺖ ﻟﻠﺜﻘــﺐ اﻷﺳــﻮد ﺑﺎﻻﻧﻄﻼق . ﺴ اﻟﻬﺎﺋﻠـﺔ ا ﺤﻴﻄـﺔ ﺑـﻪ ﺳـﻤﺤﺖ ﻟﻠﺜﻘﺐ اﻷﺳﻮد ﺑﺎﻻﻧﻄﻼق واﻟﻨﺸﺎط . ﻗﺎﻟﺖ ﺳﺎرة ﻋﻴﺴـﻌﻮن ﻣـﻦ ﺑﺮﻧـﺎﻣﺞ زﻣﺎﻟـﺔ ﺗﻠﺴﻜﻮب ﻫﺎﺑﻞ اﻟﺘﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ ﻧﺎﺳـﺎ ﰲ ﻣﺮﻛـﺰ اﻟﻔﻴﺰﻳﺎء اﻟﻔﻠﻜﻴﺔ | ﻫﺎرﻓـﺎرد وﺳﻤﻴﺜﺴـ ﻮﻧﻴﺎن، ﺑﺎﻟﻮﻻﻳـــﺎت ا ﺘﺤــﺪة وﺷــﺎرﻛ ﺖ ﰲ ﻗﻴــﺎدة ا ﺸ : "عﺮوـ ﻣﺎ ﻧﺮاه اﻵن ﻫﻮ أن ﻫﻨﺎك ﻣﺠﺎﻻت ﻣﻐﻨﺎﻃﻴﺴﻴﺔ ﻗﻮﻳﺔ وﻣﻠﺘﻮﻳﺔ وﻣﻨﻈﻤﺔ ﺑـﺎﻟﻘﺮب ﻣﻦ اﻟﺜﻘﺐ اﻷﺳـﻮد ا ﻮﺟـﻮد ﰲ ﻣﺮﻛـﺰ ﻣﺠـﺮة ﻳﻤﺘﻠﻚ ﺑﻨﻴﺔ اﺳﺘﻘﻄﺎب ﻣﺸﺎﺑﻬﺔ ﺑﺸﻜﻞ ﻻﻓـﺖ درب اﻟﺘﺒﺎﻧ ـﺔ إﱃ ﺟﺎﻧ ـﺐ أن اﻟﺜﻘ ـﺐ اﻷﺳــﻮد ﺳـﺎﺟﻴﺘﺎرﻳﻮس A * ﻳﻤﺘﻠـﻚ ﺑﻨﻴـﺔ اﺳـﺘﻘﻄﺎب ﻣﺸﺎﺑﻬﺔ ﺗﻤﺎﻣﺎً ﺑﺸﻜﻞ ﻻﻓﺖ ﻟﻠﻨﻈـﺮ وواﺿـﺢ ﻟﺘﻠﻚ اﻟﺘﻲ ﺷﻮﻫﺪت ﰲ اﻟﺜﻘـﺐ اﻷﺳـﻮد M87 * اﻷﻛﱪ واﻷﻗﻮى . ﻟﻘﺪ ﺗﻌﻠﻤﻨﺎ أن ا ﺠﺎﻻت ا ﻐﻨﺎﻃﻴﺴـﻴﺔ ا ﻟﻘﻮﻳـﺔ وا ﻨﻈﻤﺔ ﺗﻠﻌﺐ دور ﺎً ﻤﺣﺎﺳ اً ﰲ ﻛﻴﻔﻴﺔ ﺗﻔﺎﻋـﻞ اﻟﺜﻘﻮب اﻟﺴﻮداء ﻣ ﻊ ا ﺠﺮة إﺿـﺎﻓﺔ إﱃ اﻟﻐـﺎز وا ﺎدة ﻣﻦ ﺣﻮﻟﻬ ."ﺎ 23 - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 4 [ESO and DSS 2. Ack.: Davide DeMar- tin and S. Guisard ( www.eso.org/~sguisard) ]