Free Astronomy Magazine March-April 2023 ARABIC VERSION

27 and the formation of a new galaxy. Stephan’s Quintet is a group of five galaxies —NGC 7317, NGC 7318a, NGC 7318b, NGC 7319, and NGC 7320— generally located about 270 million light-years from Earth in the constellation Pegasus. The group provides a pristine labo- ratory for the study of galaxy colli- sions and their impact on the surrounding environment. Typically galaxy collisions and mergers trigger a burst of star formation; that’s not the case in Stephan’s Quintet. In- stead, this violent activity is taking place in the intergalactic medium, away from the galaxies in places where there is little to no star for- mation to obstruct the view. That clean window into the Uni- verse has allowed astronomers to watch what’s happening as one of the galaxies, NGC 7318b, violently intrudes into the group at a relative speed of roughly 800 km/second. At that speed, a trip from Earth to the Moon would take just eight min- utes. “As this intruder crashes into the group, it is colliding with an old gas streamer that likely was caused by a previous interaction between two of the other galaxies, and is causing a giant shockwave to form,” said Philip Appleton, an astronomer and senior scientist at Caltech’s IPAC, and lead investigator on the project. “As the shockwave passes through this clumpy streamer, it is creating a highly turbulent, or unsteady, cool- ing layer, and it’s in the regions af- fected by this violent activity that we’re seeing unexpected structures and the recycling of molecular hy- drogen gas. This is important be- cause molecular hydrogen forms the raw material that may ultimately form stars, so understanding its fate will tell us more about the evolution of Stephan’s Quintet and galaxies in general.“ The new observations using ALMA’s Band 6 (1.3mm wavelength) receiver —developed by NSF’s National Ra- dio Astronomy Observatory (NRAO)— allowed scientists to zoom into three key regions in extreme detail, and for the first time, build a clear picture of how the hydrogen gas is moving and being shaped on a con- tinuous basis. “The power of ALMA ٢٧ اﻛﺘﺸﻒ ﻓﺮﻖ ﻣﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﺎﺳﺘﺨﺪام ﺔ ﻣﺼﻔﻮﻓ ﻣﺮﺻﺪ أﺗﺎ ﺎﻣـﺎ اﻟﻤﻠ ﻤـ ي / ﺗﺤـﺖ اﻟ ﻤﻠ ﻤـ ي اﻟﻜﺒـ ــﺐ اﻟﻔﻀــﺎﺋﻲ وﺗﻠﺴــ ﻮبﺟــ ﻤﺲو اﻟــ ــﺪروﺟ ﻣﺼــﻨﻌًﺎ ﻹﻋــﺎدة اﻟﺘــﺪوﻳﺮﻟﻐــﺎزاﻟﻬ ـ ـــﺎرد اﻟــﺪاﻓﺊواﻟ ﺠﺰ ﻓـﻲ ﻤﺎﺳـ ﺔ ﺳـﺘ ﻔﺎن ، وﻫــﻮ ﺘﺴـ ﺐ ﻓـﻲﺣـﺪوث أﺷـ ﺎء ﻏﺎﻣﻀـﺔ . إﻟـﻰ اﻟ ﺴــﺎر ـ اﻟـ : ﺤﻘﻞ ٦ ، اﻟـﺬ ﻳﻮﺟــﺪ ــﺎرد اﻟــﺪاﻓﺊ واﻟ ــﺪروﺟ ــﺪ ﺗــﺪوﻳﺮ ﻏــﺎز اﻟﻬ ﻓــﻲﻣﺮﻛــﺰﻣﻮﺟــﺔ اﻟﺼــﺪﻣﺔ اﻟﺮ ﺴــ ﺔ ، ﻌ ــﺚ ﺗﻤﺘــﺪ ﺳــﺤﺎ ﺔ ﺣ ﻋﻤﻼﻗـــﺔ ﻣـــﻦ اﻟـــ ـ اﻟـــ ـــﺪروﺟ ـــﺎردة إﻟـــﻰذﻳـــﻞ داﻓـــﺊﻣـــﻦ اﻟﻬ ﺠﺰ ﺌﺎت اﻟ ـ ﻣـــﺮارًا وﺗﻜـــﺮارًا ﺠﺰ . ﻓـــﻲ اﻟﻤﺮﻛـــﺰ : ـ ﻛﺸﻒ اﻟ ﺤﻘﻞ ٥ اﻟـ ـﺪروﺟ ـﺎر ﻣـﻦ ﻏـﺎز اﻟﻬ ﺘ ـﺎرد ﻣﺘﺼـﻠﺘ ﻣـﻦ اﻟﻐـﺎزاﻟ ﻋـﻦ ﻏ ﻤﺘـ ـ اﻟـﺪاﻓﺊ ﺘﻤـ ﺠﺰ اﻟﻐﻼف اﻟـﺪاﻓﺊ ﻟﻠﻐـﺎزﺣـﻮل اﻟﻤﻨﻄﻘـﺔ ﺘﺼﺎدم ﻋﺎﻟﻲ اﻟﺴﺮﻋﺔ ﻐﺬ . إﻟـﻰ اﻟ ﻤـ : ـ ﻛﺸـﻒ اﻟـ ﺤﻘﻞ ٤ ﻋـﻦ ، ﻣﺸــ ﻼً ﻣـﺎ ﻌﺘﻘــﺪ اﻟﻌﻠﻤــﺎء أﻧــﮫ ﻣﺠــﺮة ــﺪروﺟ ــﺚ اﻧﻬــﺎر ﻏــﺎز اﻟﻬ ﺑﻴﺌــﺔ أﻛــ اﺳـﺘﻘﺮارًا وأﻗـﻞ اﺿــﻄﺮا ًﺎ ﺣ ـﻮﻳﻦ ﻗﺰﻣـﺔ ﺻــﻐ ة ﻓــﻲ اﻟﺘ . [ALMA (ESO / NAOJ / NRAO) / JWST / P. أ ﻠ ﺘــﻮن ) ﻣﻌﻬــﺪ ﺎﻟ ﻔﻮر ﺎ ﻟﻠﺘﻜﻨﻮﻟﻮﺟ ﺎ ( ، ﺑﻲﺳﺎﻛﺴﺘﻮن (NRAO / AUI / NSF)] ﺣﻮﻟﻬﻤﺎ وﺗﺸﻜﻴﻞ ﻣﺠﺮة . ﺟﺪﻳﺪة ان ﺧﻤﺎﺳﻴﺔ ﺳﺘﻴﻔﺎن ﻫﻲ ﻣﺠﻤﻮﻋﺔ ﻣﻦ ﺧﻤـﺲ ﻣ ﺠـﺮات NGC 7317 و NGC 7318a و NGC 7318b و NGC 7319 و NGC 7320 - ﺗﻮﺟﺪ ﺑﺸﻜﻞ ﻋﺎم ﻋﲆ ﻣﺴـﺎﻓﺔ ﺣـﻮاﱄ ٢٧٠ ﻣﻠﻴـﻮن ﺳـﻨﺔ ﺿﻮﺋﻴﺔ ﻣﻦ اﻷرض ﰲ ﻛﻮﻛﺒﺔ اﻟﻔﺮس اﻷﻋﻈﻢ . ﺗ ـﻮﻓﺮ ا ﺠﻤﻮﻋ ـﺔ ﻣﻌﻤ ـﻼً أﺻ ـﻠﻴًﺎ ﻟﺪراﺳ ـﺔ اﺻـﻄﺪام ا ﺠـﺮات وﺗﺄﺛ ﻫـﺎ ﻋ ـﲆ اﻟﺒﻴﺌ ـﺔ ا ﺤﻴﻄﺔ . ﻋﺎدةً ﻣﺎ ﺗﺆدي ﺗﺼﺎدﻣﺎت ا ﺠـﺮات واﻧ ﺪﻣﺎﺟﺎﺗﻬﺎ إﱃ اﻧﺪﻻع اﻧﻔﺠﺎر ﻧﺠﻤﻲ ؛ ﻫـﺬا ﻟﻴﺲ ﻫﻮ اﻟﺤﺎل ﰲ ﺧﻤﺎﺳﻴﺔ ﺳﺘﻴﻔﺎن . وﺑـﺪﻻً ﻣﻦ ذﻟﻚ ، ﻳﺤـﺪث ﻫـﺬا اﻟﻨﺸـﺎط اﻟﻌﻨﻴـﻒ ﰲ اﻟﻮﺳﻂ ﺑ ا ﺠﺮات ، ﺑﻌﻴﺪًا ﻋـﻦ ا ﺠـﺮات ﰲ اﻷﻣﺎﻛﻦ اﻟﺘﻲ ﻻ ﻳﻮﺟﺪ ﻓﻴﻬﺎ ﺳﻮى اﻟﻘﻠﻴﻞ ﻣـﻦ ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم ﻹﻋﺎﻗﺔ اﻟﺮؤﻳﺔ . ﻟﻘـﺪ ﺳـﻤﺤﺖ ﺗﻠﻚ ﺗﻠﻚ ا ﻟﻨﺎﻓﺬة اﻟﻨﻈﻴﻔﺔ ﰲ اﻟﻜﻮن ﻟﻌﻠﻤﺎء اﻟﻔﻠـﻚ ﺑﻤﺸﺎﻫﺪة ﻣﺎ ﻳﺤـﺪث ﻋﻨـﺪﻣﺎ ﺗﺘﺴـﻠﻞ إﺣـﺪى ا ﺠــﺮات ، NGC 7318b ، إﱃ ا ﺠﻤﻮﻋــﺔ ﺑﴪﻋﺔ ﻧﺴﺒﻴﺔ ﺗﺒﻠﻎ ٨٠٠ ﺛﺎﻧ/ ﻛﻢ ﻴﺔ ﺗﻘﺮﻳﺒًﺎ ﺑﻬﺬه اﻟﴪﻋﺔ ﺗﺴﺘﻐﺮق اﻟﺮﺣﻠﺔ ﻣﻦ اﻷر ض إﱃ اﻟﻘﻤﺮ ﺛﻤﺎﻧﻲ دﻗـﺎﺋﻖ ﻓﻘـﻂ ﺑﺤﺴـﺐ ﻓﻴﻠﻴـﺐ أﺑﻠﻴﺘﻮن اﻟ ﻋﺎﻟﻢ ﻔﻠـﻚ وأﻗـﺪم ﻋـﺎﻟﻢ ﰲ ﻣﺮﻛـﺰ ﻣﻌﺎﻟﺠﺔ وﺗﺤﻠﻴﻞ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﺘﺎﺑﻊ ﻌﻬــﺪ ﻛﺎﻟﻴﻔﻮرﻧﻴــﺎ ﻟﻠﺘﻜﻨﻮﻟﻮﺟﻴــﺎ وﻛﺒــ اﻟﺒﺎﺣﺜ ﰲ ﻫﺬا ا ﴩ : وع ﺑﻴﻨﻤﺎ ﺗﻤﺮ ﻣﻮﺟـﺔ اﻟﺼﺪﻣﺔ ﻋﱪ ﻫﺬا اﻟﺘﺪ ﻓﻖ ا ﺘﻜﺘﻞ ﻓﺈﻧﻬﺎ ﺗﺨﻠﻖ ﻃﺒﻘـﺔ ﺗﱪﻳـﺪ ﺷـﺪﻳﺪة اﻻﺿـﻄﺮاب أو ﻏـ ﻣﺴﺘﻘﺮة وﰲ ا ﻨﺎﻃﻖ ا ﺘﺄﺛﺮة ﺑﻬـﺬا اﻟﻨﺸـﺎط اﻟﻌﻨﻴﻒ ﻧﺮى ﻫﻴﺎﻛـﻞ ﻏـ ﻣﺘﻮﻗﻌـﺔ وإﻋـﺎ دة ﺗﺪوﻳﺮ ﻏﺎز اﻟﻬﻴﺪروﺟ اﻟﺠﺰﻳﺌﻲ ﻫﺬا ﻣﻬﻢ ﻷن اﻟﻬﻴﺪروﺟ اﻟﺠﺰﻳﺌﻲ ﻳﺸﻜﻞ ا ﺎدة اﻟﺨﺎم اﻟﺘﻲ ﻗﺪ ﺗﺸﻜﻞ اﻟﻨﺠﻮم ﰲ اﻟﻨﻬﺎﻳ ﺔ ، ﻟﺬا ﻓـﺈن ﻓﻬـﻢ ﻣﺼ ﻫﺎ ﺳﻴﺨﱪﻧﺎ ا ﺰﻳﺪ ﻋﻦ ﺗﻄﻮر ﺧﻤﺎﺳﻴ ﺔ ﺳﺘﻴﻔﺎن وا ﺠﺮات ﺑﺸـﻜﻞ ﻋـﺎم . " اﻷرﺻـﺎد اﻟﺠﺪﻳﺪة ﺑﺎﺳﺘﺨﺪام ﺟﻬﺎز اﺳﺘﻘﺒﺎل اﻟﻨﻄﺎق ٦ ) اﻟﻄﻮل ا ﻮﺟﻲ ١.٣ ﻣـﻦ ( ﻣﻢ أ ـﺎ ) ﻣﺮﺻـﺪ ( اﻟﺬي ﻃـﻮره ا ﺮﺻـﺪ اﻟـﻮﻃﻨﻲ ﻟﻌﻠـﻢ اﻟﻔﻠـﻚ اﻟﺮادﻳﻮي اﻟﺘﺎﺑﻊ ﺆﺳﺴـﺔ اﻟﻌﻠـﻮم اﻟﻮﻃﻨﻴـﺔ اﻷﻣﺮﻳﻜﻴﺔ ﺳﻤﺤﺖ ﻟﻠﻌﻠﻤﺎء ﺑﺎﻟﺘﻜﺒ ﰲ ﺛـﻼ ث ﻣﻨﺎﻃﻖ رﺋﻴﺴﻴﺔ ﺑﺘﻔﺎﺻﻴﻞ ﻣﺘﻨﺎﻫﻴـﺔ وﻟﻠﻤـﺮة اﻷوﱃ ﺗﻜﻮﻳﻦ ﺻﻮرة واﺿﺤﺔ ﻋﻦ ﻛﻴﻒ ﻳﺘﺤﺮك ﻏـﺎز اﻟﻬﻴــﺪروﺟ وﻳﺘﺸــﻜﻞ ﻋــﲆ أﺳـﺎس . ﻣﺴﺘﻤﺮ ﻗﺎل ﺟﻮ ﺑﻴﺴﻜﻲ ، ﻣﺴﺆول ﺑﺮﻧـﺎﻣﺞ ﻣﺮﺻـــﺪ أ ـــﺎ ) ( ﰲ ﻣﺆﺳﺴـــﺔ اﻟﻌﻠـــﻮم ـــــــــــــــ ـــــ اﻟﻮﻃﻨﻴﺔ اﻷﻣﺮﻳﻜﻴـﺔ " إن ﻗـﻮة ﻣﺮﺻـﺪ أ ـﺎ ) ( واﺿﺤﺔ ﰲ ﻫﺬه اﻷرﺻﺎد ﺣﻴﺚ ﺗـﻮﻓﺮ ﻟﻌﻠﻤـﺎء اﻟﻔﻠ ـﻚ رؤى ﺟﺪﻳ ـﺪة وﻓﻬﻤ ًـﺎ أﻓﻀـﻞ ﻟﻬ ـﺬ ه اﻟﻌﻤﻠﻴـﺎت ﻏـ ا ﻌﺮوﻓـﺔ ﺳـﺎﺑﻘً . ﺎ ﻛﺸـﻔﺖ ا ﻨﻄﻘﺔ اﻟﻮاﻗﻌﺔ ﰲ ﻣﺮﻛـﺰ ﻣﻮﺟـﺔ اﻟﺼـﺪﻣﺔ اﻟﺮﺋﻴﺴﻴﺔ ، واﻟﺘﻲ ﻳﻄﻠﻖ ﻋﻠﻴﻬﺎ اﺳـﻢ اﻟﺤﻘـﻞ اﻟﺴﺎدس ﻋﻦ ﺳﺤﺎﺑﺔ ﻋﻤﻼ ﻗﺔ ﻣﻦ اﻟﺠﺰﻳﺌـﺎت اﻟﺒﺎردة اﻟﺘﻲ ﻳﺘﻢ ﺗﻔﺘﻴﺘﻬﺎ واﻣﺘـﺪادﻫﺎ إﱃ ذﻳـﻞ ﻃﻮﻳـﻞ ﻣـﻦ اﻟﻬﻴـﺪروﺟ اﻟﺠﺰﻳﺌـﻲ اﻟـﺪاﻓﺊ وإﻋﺎدة ﺗﺪوﻳﺮﻫﺎ ﻣﺮارًا وﺗﻜـﺮارًا ﺧـﻼل ﻫـﺬه ا ﺮاﺣﻞ ﻧﻔﺴﻬﺎ . ﻗﺎل أﺑﻠﻴﺘﻮن " : ﻣﺎ ﻧـﺮاه ﻫـﻮ ﺗﻔﻜﻚ ﺳﺤﺎﺑﺔ ﻋﻤﻼﻗﺔ ﻣﻦ اﻟﺠﺰﻳﺌﺎت اﻟﺒـﺎردة ﰲ ﻏﺎز ﺷﺪﻳﺪ اﻟﺴﺨﻮﻧﺔ ، وﻣﻦ ا ﺜ ﻟﻼﻫﺘﻤﺎم أن ا ﻟﻐﺎز ﻻ ﻳﻨﺠﻮ ﻣﻦ اﻟﺼﺪﻣﺔ ، ﺑﻞ ﻳﻤﺮ ﻓﻘﻂ ﻋﱪ ﻣﺮاﺣﻞ داﻓﺌﺔ وﺑﺎردة ." " ﻟﻢ ﻧﻔﻬﻢ ﺗﻤﺎﻣًـﺎ ﻫﺬه اﻟﺪورات ﺣﺘﻰ اﻵن ، ﻟﻜﻨﻨﺎ ﻧﻌﻠﻢ أن اﻟﻐﺎز ﻳﺘﻢ إﻋﺎدة ﺗﺪوﻳﺮه ﻷن ﻃﻮل اﻟﺬﻳﻞ أﻃﻮل ﻣـﻦ اﻟﻮﻗﺖ اﻟﺬي ﻳﺴﺘﻐﺮﻗﻪ ﺗﺪﻣ اﻟﺴـﺤﺐ اﻟﺘـﻲ ﻳﺘﻜﻮن ﻣﻨﻬﺎ ". ﻟﻴﺲ اﻟﻨﺸﺎط اﻟﻐﺮﻳﺐ اﻟﻮﺣﻴـﺪ اﻟﻨﺎﺗﺞ ﻋـﻦ ﻣﻮﺟـﺎت اﻟﺼـﺪﻣﺔ . ﰲ ا ﻨﻄﻘـﺔ ا ﺴﻤﺎة اﻟﺤﻘﻞ اﻟﺨـﺎﻣﺲ اﻛﺘﺸـﻒ اﻟﻌﻠﻤـﺎء ﺳﺤﺎﺑﺘﺒ ﻣﻦ اﻟﻐﺎز اﻟﺒﺎرد ﻣﺘﺼـﻠﺘ ﺑﺘﻴـﺎر ﻣ ﻦ ﻏﺎز اﻟﻬﻴﺪروﺟ اﻟﺠﺰﻳﺌﻲ اﻟـﺪاﻓﺊ ، ﻣـﻦ اﻟﻐﺮﻳﺐ أن إﺣﺪى اﻟﻐﻴﻮم اﻟﺘﻲ ﺗﺸﺒﻪ رﺻﺎﺻﺔ ﻋﺎﻟﻴﺔ اﻟﴪﻋﺔ ﻣﻦ ﻏﺎز اﻟﻬﻴـﺪروﺟ اﻟﺒـﺎرد ﺗﺼﻄﺪم ﺑﺨﻴﻂ ﻛﺒ ﻳﺸﺒﻪ اﻟﺨﻴﻂ ﻣﻦ اﻟﻐـﺎز ا ﻨﺘﴩ - ﺧﻠﻘﺖ ﺣﻠﻘﺔ ﰲ اﻟﻬﻴﻜﻞ أﺛﻨﺎء ﺛﻘﺒﻬﺎ . ﺗﻐﺬي اﻟﻄﺎﻗﺔ اﻟﻨﺎﺗﺠﺔ ﻋـﻦ ﻫـﺬا اﻻﺻـﻄﺪام اﻟﻐﻼف اﻟﺪاﻓﺊ ﻟﻠﻐﺎز ﺣﻮل ا ﻨﻄﻘﺔ ا ﺤﻴﻄـﺔ ـــــــــــــــــ ﻣﺎرس أﺑﺮﻳﻞ 2023