Free Astronomy Magazine July-August 2023 ARABIC VERSION

T in the early stages of merging, when the two galaxies could still be con- sidered clearly separate entities. But these new results show a pair of quasars blazing away in such close proximity, a mere 10,000 light-years apart, that their original host galax- ies are likely well on their way to be- coming a single giant elliptical gal- axy. Searching for pairs of supermas- sive black holes so close to each other during this early epoch is like his artist's impression illus- trates that astronomers using an array of ground- and space-based telescopes, including Gemini North on Hawai‘i, have uncovered a closely bound duo of energetic quasars — the hall- mark of a pair of merging galax- ies — seen when the Universe was only three billion years old. This discovery sheds light on the evolution of galaxies at “cosmic noon,” a period in the history of the Universe when galaxies un- derwent bursts of furious star formation. [International Gemini Observatory/NOIRLab/NSF/AURA/ M. Zamani, J. da Silva] trying to find the proverbial needle in a haystack. The challenge is that most black-hole pairs are too close to distinguish individually. To defin- itively detect such a system, the two supermassive black holes need to be actively accreting and shining as quasars simultaneously, conditions that are extremely rare. Statistically, for every 100 supermassive black holes only one should be actively ac- creting at a given time. 41 Astronomers know, however, that the distant Universe should be brimming with pairs of supermassive black holes embedded within merging galaxies. The first hints of such a system were found in data from the NASA/ESA Hubble Space Telescope, which re- vealed two closely aligned pinpoints of light in the distant Universe. To verify the true nature of this system, the team searched through ESA’s Gaia observatory’s vast database and found that this system had an appar- ent “jiggle,” which could be the re- sult of sporadic changes in a black hole's feeding activity. The team then used the Gemini Multi-Object Spec- trograph (GMOS) and the Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, which provided the team with independent measure- ments of the distance to the quasars and confirmed that the two objects were both quasars rather than a chance alignment of a single quasar with a foreground star. Further stud- ies with the W.M. Keck Observatory, NSF’s Karl G. Jansky Very Large Array, and NASA’s Chandra X-ray Observa- tory also helped to confirm these ob- servations. “The confirmation process wasn’t easy and we needed an array of telescopes covering the spectrum from X-rays to the radio to finally confirm that this system is indeed a pair of quasars, instead of, say, two images of a gravitationally lensed quasar,” said co-author Yue Shen, an astronomer at the University of Illi- nois. “We don't see a lot of double quasars at this early time. And that's why this discovery is so exciting. Knowing about the progenitor pop- ulation of black holes will eventually tell us about the emergence of super- massive black holes in the early Uni- verse, and how frequent those merg- ers could be,” said graduate student Yu-Ching Chen of the University of Illinois at Urbana-Champaign, lead author of this study, which is pub- lished in the journal Nature .     41 ﺧﻼل ا ﺮاﺣﻞ اﻷوﱃ ﻣﻦ اﻻﻧﺪﻣﺎج ﻋﻨﺪﻣﺎ ﻛـﺎن ﻻ ﻳﺰال ﻣﻦ ا ﻤﻜﻦ اﻋﺘﺒـﺎ ر ا ﺠـﺮﺗ ﻛﻴـﺎﻧ ﻣﻨﻔﺼﻠ ﺑﻮﺿﻮح ﻟﻜﻦ ﻫﺬه اﻟﻨﺘﺎﺋﺞ اﻟﺠﺪﻳﺪة ﺗُﻈﻬِﺮ ﺛﻨﺎﺋﻲ ﻣﻦ اﻟﻜـﻮازار ات اﻟﺘـﻲ ﺗﺸـﺘﻌﻞ ﺑﻌﻴﺪًا ﰲ ﻣﺜﻞ ﻫﺬا اﻟﻘﺮب اﻟﻘﺮﻳـﺐ ﻋـﲆ ﺑﻌـﺪ 10,000 ﺳـﻨﺔ ﺿـﻮﺋﻴﺔ ﻓﻘـﻂ ﺑﺤﻴــﺚ ﻣــﻦ ا ﺤﺘﻤﻞ أن ﺗﻜﻮن ﻣﺠﺮاﺗﻬﺎ ا ﻀﻴﻔﺔ اﻷﺻـﻠﻴﺔ ﰲ ﻃﺮﻳﻘﻬﺎ ﻟﺘﻜﻮن ﻣﺠﺮة إﻫﻠﻴﻠﺠﻴـﺔ ﻋﻤﻼﻗـﺔ . واﺣﺪة إن اﻟﺒﺤـﺚ ﻋـﻦ أزواج ﻣـﻦ اﻟﺜﻘـﻮب ـــــــ اﻟﺴﻮداء ﻓﺎﺋﻘﺔ اﻟﻜﺘﻠﺔ ﻗﺮﻳﺒﺔ ﺟﺪًا ﻣﻦ ﺑﻌﻀﻬﺎ اﻟﺒﻌﺾ ﺧﻼل ﻫـﺬه اﻟﺤﻘﺒـﺔ ا ﺒﻜـﺮة ﻳﺸـﺒﻪ ﻣﺤﺎوﻟﺔ اﻟﻌﺜﻮر ﻋﲆ إﺑﺮة ﰲ ﻛﻮﻣﺔ ﻗـﺶ ﻛﻤـﺎ ﻳﻘﻮل ا ﺜﻞ إن . اﻟﺘﺤﺪي ﻳﻜﻤـﻦ ﰲ أن ﻣﻌﻈـﻢ ﺛﻨﺎﺋﻴﺎت اﻟﺜﻘﻮب اﻟﺴﻮداء ﻗﺮﻳﺒـﺔ ﺟـﺪًا ﻟﻴـﺘﻢ ﺗﻤﻴﻴﺰﻫﺎ ﺑﺸﻜﻞ ﻓﺮدي ﻻﻛﺘ . ﺸـﺎف ﻣﺜـﻞ ﻫـﺬا اﻟﻨﻈﺎم ﺑﺸﻜﻞ ﻧﻬﺎﺋﻲ ﻳﺠﺐ أن ﻳ ﱰاﻛﻢ اﻟﺜﻘﺒﺎن اﻷﺳﻮدان اﻟﻬﺎﺋﻼن ﺑﺸـﻜﻞ ﻧﺸـﻂ وﻳﺘﺄﻟﻘـﺎن ﻣﺜﻞ اﻟﻜﻮازارات ﰲ وﻗﺖ واﺣﺪ و ﻫﻲ ﻇـﺮوف ﻧﺎدرة ﻟﻠﻐﺎﻳﺔ ـــــ ــ ﻧﺎدرة ﻟﻠﻐﺎﻳﺔ . إﺣﺼﺎﺋﻴًﺎ ﻟﻜﻞ 100 ﺛﻘﺐ أﺳـﻮد ﻓﺎﺋﻖ اﻟﻜﺘﻠﺔ ﻳﺠﺐ أن ﻳﱰاﻛﻢ ﺛﻘﺐ واﺣﺪ ﻓﻘﻂ ﺑﻨﺸﺎط ﰲ وﻗـﺖ ﻣﻌـ . ﻳﻌـﺮف اﻟ ﻌﻠﻤـﺎء أ ن اﻟﻜﻮن اﻟﺒﻌﻴﺪ ﻳﺠﺐ أن ﻳﻜﻮن ﻣﻤﺘ ﻠﺌﺎً ﺑﺜﻨﺎﺋﻴﺎت اﻟﺜﻘـﻮب اﻟﺴـﻮداء اﻟﻬﺎﺋﻠـﺔ داﺧـﻞ ا ﺠـﺮات ا ﻨﺪﻣﺠﺔ . ﻟﻘﺪ ﺗﻢ اﻟﻌﺜﻮر ﻋﲆ اﻻﺷﺎرات اﻷوﱃ ﺜﻞ ﻫﺬا اﻟﻨﻈﺎم ﰲ اﻟﺒﻴﺎﻧـﺎت ﻣـﻦ ﺗﻠﺴـﻜﻮب ﻫﺎﺑـﻞ واﻟﺘـﻲ ﻛﺸـﻔﺖ ﻋـﻦ ﻧﻘﻄﺘـ ﻲ ﺿـﻮء ﻣﺘﻄﺎﺑﻘﺘ ﰲ اﻟﻜﻮن اﻟﺒﻌﻴﺪ ، و ﻟﻠﺘﺤﻘـﻖ ﻣـﻦ اﻟﻄﺒﻴﻌﺔ اﻟﺤﻘﻴﻘﻴﺔ ﻟﻬﺬا اﻟﻨﻈﺎم ﺑﺤﺚ اﻟﻔﺮﻳﻖ ﻣﻦ ﺧﻼل ﻗﺎﻋﺪة اﻟﺒﻴﺎﻧﺎت ﺮﺻﺪ ﻏﺎﻳﺎ اﻟﺘـﺎﺑﻊ ﻟﻮﻛﺎﻟﺔ اﻟﻔﻀﺎ ء اﻷوروﺑﻴـﺔ ووﺟـﺪوا أن ﻫـﺬا اﻟﻨﻈﺎم ﺑﻪ اﻫﺘﺰاز " واﺿﺢ " ﻗﺪ واﻟﺬي ﻳﻜـﻮن ﻧﺘﻴﺠـﺔ ﺗﻐﻴـ ات ﰲ ﻧﺸـﺎط ﺗﻐﺬﻳـﺔ اﻟﺜﻘـﺐ اﻷﺳﻮد . اﺳﺘﺨﺪم اﻟﻔﺮﻳﻖ ﺑﻌﺪ ذﻟـﻚ ﻣﻄﻴـﺎف ﺟﻴﻤﻴﻨﻲ ﻣﺘﻌﺪد اﻷﺟﺮام (GMOS) و ﻣﻄﻴـﺎف اﻷﺷــﻌﺔ اﻟﻘﺮﻳﺒــﺔ ﻣــﻦ ﺗﺤــﺖ اﻟﺤﻤــﺮاء (GNIRS) ﻣﻤ ــﺎ زود اﻟﻔﺮﻳ ــﻖ ﺑﻘﻴﺎﺳــﺎت ﻣﺴﺘﻘﻠﺔ ﻟﻠﻤﺴﺎﻓﺔ إﱃ اﻟﻜﻮازارا ت وأﻛﺪ أن ﻛﻼ اﻟﺠﺮﻣ ﻛﺎﻧﺎ ﻛـﻮازارات ﺑـﺪﻻً ﻣـﻦ ﻣﺤـﺎذاة ﻟـ ﻛﻮازار أ ﻨﺠﻢ ﻣﺎﻣـﻪ اﻟﺼـﺪﻓﺔ . ﻣﺰﻳـﺪ ﻣـﻦ اﻟﺪراﺳــﺎت ﺑﺎﻟﺘﻌــﺎون ﻣــﻊ ﻣﺮﺻــﺪ ﻛﻴــﻚ وﻣﺼﻔﻮﻓﺔ ا ﺮاﺻﺪ اﻟﻜﺒ ة و ﻣﺮﺻﺪ ﺗﺸﺎﻧﺪرا اﻟﻔﻀﺎﺋﻲ ﻟﻸﺷﻌﺔ اﻟﺴﻴﻨﻴﺔ ﺳﺎﻋﺪت اﻳﻀـﺎ ﰲ ﺗﺄﻛﻴﺪ ﻫﺬه اﻷرﺻﺎد . " ﻟﻢ ﺗﻜﻦ ﻋﻤﻠﻴﺔ اﻟﺘﺄﻛﻴـﺪ ﺳﻬﻠﺔ واﺣﺘﺠﻨﺎ إﱃ ﺗﻠ ﻋﺪة ﺴـﻜﻮﺑﺎت ﺗﻐﻄـﻲ اﻟﻄﻴـﻒ ﻣـﻦ اﻷﺷـﻌﺔ اﻟﺴـﻴﻨﻴﺔ إﱃ اﻟﺮادﻳـﻮ ﻠﻟ ﺘﺄﻛﻴﺪ أن ﻫﺬا اﻟﻨﻈـﺎم ﻫـﻮ ﺑﺎﻟﻔﻌـﻞ ﺛﻨـﺎﺋﻲ ﻛﻮازارات ﺑﺪﻻً ﻣـﻦ ﻛـﻮازار ﺻـﻮرة ﻣﻜـﺮرة ﺑﻌﺪﺳﺔ ﺟﺎذﺑﻴﺔ . ﻗﺎل ا ﺆﻟﻒ ا ﺸﺎرك ﻳﻮ ﺷ ﻋﺎﻟﻢ اﻟﻔﻠﻚ ﰲ ﺟﺎﻣﻌﺔ إﻟﻴﻨﻮي " ﻻ ﻧﺮى اﻟﻜﺜـ ﻣﻦ اﻟﻜﻮازارت اﻟﺜﻨﺎﺋﻴﺔ ﰲ ﻫﺬا اﻟﻮﻗﺖ ا ﺒﻜﺮ ﻟﺬا ﻫﺬا ا ﻻﻛﺘﺸﺎف ﻣﻬﻢ ﻟﻠﻐﺎﻳﺔ . ﻗﺎل ﻳـﻮ ﺗﺸـﻴﻨﻎ ﺗﺸ ﻃﺎﻟﺐ اﻟﺪراﺳﺎت ا ﻟﻌﻠﻴﺎ ﺑﺠﺎﻣﻌﺔ إﻟﻴﻨﻮي ﰲ أورﺑﺎﻧﺎ ا ﺆﻟﻒ اﻟﺮﺋﻴﴘ ﻟﻬﺬه اﻟﺪراﺳﺔ اﻟﺘﻲ ﻧُﴩت ﰲ ﻣﺠﻠﺔ ﻧﻴﺘﴩ ": إن ﻣﻌﺮﻓـﺔ أﺳـﻼف ا ﻟﺜﻘﻮب اﻟﺴﻮداء ﺳﻴﺨﱪﻧﺎ ﻋﻦ ﻇﻬﻮر ﺛﻘﻮب ﺳﻮداء ﻫﺎﺋﻠﺔ ﰲ ﺑﺪاﻳﺎت اﻟﻜﻮن وﻣﺪى ﺗﻜـﺮار ﻋﻤﻠﻴﺎت اﻻﻧﺪﻣﺎج ﻫﺬه . ﻳﻮﻟﻴﻮ - ﺃﻏﺴﻄﺲ 2 0 2 3