Free Astronomy Magazine July-August 2023 ARABIC VERSION

17 _ Galaxy collisions can happen out of a variety of different scenarios, often involving a larger galaxy and a smaller satellite galaxy. As they drift near one another, the satellite galaxy can attract one of the larger galaxy’s primary spiral arms, pulling it out of its orbit. Or the satellite galaxy can actually intersect with the larger gal- axy, causing significant distortions to its own structure. In other cases, a collision can lead to a merger if nei- ther member has enough momen- tum to continue on after colliding. In all these scenarios, stellar material from both galaxies mixes through a gradual combining and redistribu- tion of gas, like two puddles of liq- uid that are slowly bleeding into each other. The resulting collecting and compression of the gas can then trigger star formation. A head-on collision, however, would be more like pouring liquid from two sepa- rate cups into a shared bowl. When the Taffy Galaxies’ collided, their galactic disks and gaseous compo- nents smashed right into each other. This resulted in a massive injection of energy into the gas, causing it to be- come highly turbulent. As the pair emerged from their collision, high- velocity gas was pulled from each galaxy, creating a massive gas bridge between them. The turbulence of the stellar material throughout the bridge is now prohibiting the collec- tion and compression of gas that are required to form new stars. The Gemini North observations of this object were led by Analía Smith Castelli, an astronomer with the In- stituto de Astrofísica de La Plata in Argentina. Argentina is one of the partners in the International Gemini Observatory.     JULY-AUGUST 2023 اﻟﺘﻘﻂ ﺗﻠﺴ ﻮب ﻧﻮر ﺟ ﻤ وﻫﻮ اﺣـﺪ ﺗﻠﺴـ ﻮ ﺎت ـ ﺟ ﻤ ﻣﺮﺻـﺪ اﻟـﺪوﻟﻲ اﻟـﺬ ـﺪﻳﺮﻩ ﻣﺨﺘـ ﻧـﻮﻳﺮﻻب ـﺔ ــﺔ اﻷﻣﺮ ﻜ ﻣﺆﺳﺴـﺔ اﻟﻌﻠـﻮم اﻟﻮﻃﻨ ﻫــﺬﻩ اﻟﺼـﻮرة اﻟﻤﺒﻬــﺮة ) اﻟﺼـﻔﺤﺔ اﻟﺴـﺎ ﻘﺔ ( ﻟﻤـﺎ ﺴـﻤﻰﻣﺠــﺮات ﺗـﺎﻓﻲ - UGC 12914 و UGC 12915. ﺣـﺪثﻗﺒـﻞ ﺣـﻮاﻟﻲ اﻟﺘﺼـﺎدم اﻟﻤ ﺎﺷـﺮ اﻟـﺬ ٢٥ ﻣﻠﻴـﻮنﺳـﻨﺔ ﻣـﻦ ﺎ ﻇﻬﻮرﻫﻤــ ﻓــﻲﻫــﺬﻩ اﻟﺼــﻮرة . ﻤﺘــﺪ ﺟﺴــﺮﻣــﻦ اﻟﻐــﺎزﺷــﺪ ﺪ اﻻﺿــﻄﺮاب وﺧــ ــﻮﻳﻦ ﻧ ﻤــﻲﻛﺒــ ﺎﻟﻲ ﻣــﻦ ﺗ اﻟﻤﺠﺮ ﻋﻠﻰ اﻟﻔﺠﻮة ﺑ . ﺼﻒ اﻟﻔ ﺪﻳﻮ أﻋﻼﻩ اﻟ ـ . ﺠﺴﺮ ]International Gemini Observatory/NOIRLab/DOE/ NSF/AURA, T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Observatory/NSF’s NOIRLab), M. Rodriguez (Gemini Observatory/NSF’s NOIRLab), M. Zamani & D. deMartin (NSF’s NOIRLab), ESA/Hubble/L. Calcada، ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ إن ﺗﺼﺎدﻣﺎت ا ﺠﺮات ﻳﻤﻜﻦ ﺣـﺪوﺛﻬﺎ وﻓـﻖ ﻣﺠﻤﻮﻋــﺔ ﻣﺘ ﻨﻮﻋــﺔ ﻣــﻦ اﻟﺴــﻴﻨﺎرﻳﻮﻫﺎت ا ﺨﺘﻠ ﻔﺔ واﻟﺘﻲ ﻏﺎﻟﺒًﺎ ﻣﺎ ﺗﺘﻀﻤﻦ ﻣﺠﺮة أﻛـﱪ وﻣﺠﺮة ﺗﺎﺑﻌﺔ أﺻﻐﺮ . ﻋﻨﺪﻣﺎ ﺗﻨﺠﺮف ﺑﺎﻟﻘﺮب ﻣﻦ ﺑﻌﻀﻬﺎ اﻟﺒﻌﺾ ﻳﻤﻜﻦ ﻟ ﻠﻤﺠﺮة اﻟﺼـﻐ ة اﻟﺘﺎﺑﻌــﺔ ﺟــﺬب أﺣــﺪ اﻷذرع اﻟﺤﻠﺰوﻧﻴــ ﺔ اﻷﺳﺎﺳﻴﺔ ﻟﻠﻤﺠﺮة اﻷﻛﱪ ﺣﺠﻤًﺎ ﻣﻤﺎ ﻳﺴﺤﺒﻬﺎ ﺧﺎرج ﻣﺪارﻫﺎ ، أو ﻳﻤﻜﻦ أن ﺗﺘﻘﺎﻃﻊ ا ﺠـﺮة اﻟﺼﻐ ة اﻟﺘﺎﺑﻌـﺔ ﻣـﻊ ا ﺠـﺮة اﻷﻛـﱪ ﻤـﺎ ﻣ ﻳﺘﺴﺒﺐ ﰲ ﺗﺸﻮﻫﺎت ﻛﺒ ة ﰲ ﺑﻨﻴﺘﻬﺎ . ﻳﺤـﺪث ﰲ ﺣﺎﻻت أﺧﺮى أن ﻳﺆدي اﻟﺘﺼﺎدم إﱃ اﻧﺪﻣﺎج إذا ﻟﻢ ﻳﻜﻦ ﻟﺪى أي ﻣﻦ اﻷﻋﻀﺎء اﻟﺰﺧﻢ اﻟﻜﺎﰲ ﻟﻼﺳﺘﻤﺮار ﺑﻌﺪ اﻻﺻﻄﺪام . ﻋﻤﻮﻣﺎً ﰲ ﻛﻞ ﻫﺬه اﻟﺴﻴﻨﺎرﻳﻮﻫﺎت ﺗﺨﺘﻠﻂ ا ـﻮاد اﻟﻨﺠﻤﻴـﺔ ﻣـﻦ ﻛﻠﺘﺎ ا ﺠﺮﺗ ﻣﻦ ﺧـﻼل اﻻﺗﺤـﺎد اﻟﺘـﺪرﻳﺠﻲ وإﻋﺎدة ﺗﻮزﻳﻊ اﻟﻐـ ﺎز ﻣﺜـﻞ ﺑـﺮﻛﺘ ﻣﻤﺘﻠﺌـﺔ ﺑ ﺎﻟﺴﻮاﺋﻞ اﻟﺘـﻲ ﺗﺘـﺪﻓﻖ ﺑـﺒﻂء ﰲ ﺑﻌﻀـﻬﻤﺎ . اﻟﺒﻌﺾ . إن ﺗﺠﻤ ﻊ اﻟﻐﺎز وﺿـﻐﻄﻪ اﻟﻨـﺎﺗﺞ ﻳﻤﻜـﻦ أن ﻳﺆدي ﺑﻌﺪ ذﻟﻚ إﱃ ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم . وﻣـﻊ ذﻟـﻚ ﻓﺈن اﻟﺘﺼﺎدم ا ﺒﺎﴍ ﺳﻴﻜﻮن أﺷـﺒﻪ ﺑﺼـﺐ اﻟﺴﺎﺋﻞ ﻣﻦ ﻛﻮﺑ ﻣﻨﻔﺼﻠ ﰲ وﻋﺎء ﻣﺸﱰك ﻋﻨﺪﻣﺎ اﺻﻄﺪ ﻣﺖ ﻣﺠـﺮات ﺗـﺎﰲ اﺻـﻄﺪﻣﺖ أﻗﺮاص ا ﺠﺮة وا ﻜﻮﻧﺎت اﻟﻐﺎزﻳـﺔ ﺑﺒﻌﻀـﻬﺎ اﻟﺒﻌﺾ ﻣﺎ أدى إﱃ ﺣﻘﻦ ﻛ ﻤﻴﺎت ﻫﺎﺋﻠـﺔ ﻣـﻦ اﻟﻄﺎﻗﺔ ﰲ اﻟﻐﺎز ﻣﻤﺎ ﺟﻌﻠﻪ ﺷﺪﻳﺪ اﻻﺿﻄﺮاب و ﻋﻨﺪﻣﺎ ﺧﺮج اﻟﺜﻨـﺎﺋﻲ ﻣـﻦ ﺗﺼـﺎدﻣﻬﻤﺎ ﺗـﻢ ﺳﺤﺐ ﻏﺎز ﻋﺎﱄ اﻟﴪﻋﺔ ﻣﻦ ﻛﻞ ﻣﺠﺮة ﻣﻤـﺎ ﻟﺘﺸﻜﻞ ﺮ ﻏﺎز ـﺟﺴ ي ﺿـﺨﻢ ﺑﻴﻨﻬﻤـﺎ ﻳﻤﻨـﻊ اﺿﻄﺮاب ا ـﻮاد اﻟﻨﺠ ﻤﻴـﺔ ﰲ ﺟﻤﻴـﻊ أﻧﺤـﺎء اﻟﺠﴪ اﻵن ﻟﺠﻤﻊ وﺿـﻐﻂ اﻟﻐـﺎز ا ﻄﻠـﻮب ﻟﺘﺸﻜﻴﻞ ﻧﺠﻮم ﺟﺪﻳﺪة . ﻋﺎ ﺔ اﻟﻔﻠﻚ ت ﻗﺎد أﻧﺎﻟﻴﺎ ﺳـﻤﻴﺚ ﻛﺎﺳـﺘﻴﲇ ﰲ ﻣﻌﻬﺪ ﻻ ﺑﻼﺗـﺎ ﰲ اﻷرﺟﻨﺘـ ﻋﻤﻠﻴـﺎت رﺻـﺪ ﺗﻠﺴﻜﻮب ﺟﻴﻤﻨﻲ ﻧﻮرث ﻟﻬﺬه ا ﺠﺮات .