Free Astronomy Magazine January-February 2024 ARABIC VERSION

A n international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This ‘fast radio burst’ (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory’s (ESO) Very Large Tele- scope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our S u n ’s total emis- sion over 30 years. The discovery of the burst, named FRB 2022- 0610A, was made in June last year by the ASKAP radio telescope in Australia and it smashed the team’s previous distance record by 50 percent. “Using ASKAP’s array of dishes, we were able to determine precisely where the burst came from,” says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published in Science . “Then we used [ESO’s VLT] in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies.” The discovery confirms that FRBs can be used to measure the ‘missing’ matter between galax- ies, providing a new way to ‘weigh’ the Universe. Current methods of estimating the mass of the Universe are giving con- flicting answers and challenging the standard model of cosmology. “If we count up the amount of normal matter in the Universe — the atoms that we are all made of — we find that more than half of what should be there today is missing,” says Ryan Shannon, a professor at the Swin- burne University of Technology in Australia, who also co-led the study. “We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it’s impossible to see using normal techniques.” “Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can ‘see’ all the electrons, and that allows us to measure how much stuff is between the galaxies,” Shannon says. Finding distant FRBs is key to accu- rately measuring the Universe’s missing matter, as shown by the late Australian astronomer Jean-Pierre (‘J-P’) Macquart in 2020. “J-P showed that the further away a fast radio burst is, the more dif- fuse gas it reveals between the galaxies. This is now known as the Macquart relation. Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Uni- verse,” says Ryder. “While we still don’t know what causes these massive bursts of en- ergy, the paper confirms that fast radio bursts are common events in the cosmos and that we will be able to use them to detect matter be- tween galaxies, and better under- stand the structure of the Uni- verse,” says Shannon. The result represents the limit of what is achievable with telescopes today, although astronomers will soon have the tools to detect even older and more distant bursts, pin down their source galaxies and measure the Universe’s missing mat- ter. The international Square Kilo- metre Array Observatory is currently building two radio telescopes in South Africa and Australia that will be capable of finding thousands of FRBs, including very distant ones that cannot be detected with cur- rent facilities. ESO’s Extremely Large Telescope, a 39-metre telescope under construc- tion in the Chilean Atacama Desert, will be one of the few telescopes able to study the source galaxies of bursts even further away than FRB 20220610A.    JANUARY-FEBRUARY 2024 ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 21 رﺻـﺪ ﻓﺮﻳﻖ دوﱄ ﺗﺪﻓﻘﺎً اً ﺑﻌﻴﺪ ﻮﺟﺎت اﻟﺮادﻳﻮ اﻟﻜﻮﻧﻴﺔ اﻟﺪاﺋﻤﺔ أﻗﻞ ﻣـﻦ ﻣﻠـﲇ ﺛﺎﻧﻴـﺔ . ﻫـﺬا اﻟﺘﺪﻓﻖ اﻟﺮادﻳﻮي اﻟﴪﻳ ﻊ أﺑﻌﺪ ﻣﺎ ﺗﻢ اﻛﺘﺸﺎﻓﻪ ﻋﲆ اﻹﻃﻼق وﺗﻢ ﺗﺤﺪﻳـﺪ ﻣﺼـﺪره ﺑﻮاﺳـﻄﺔ اﻟﺘﻠﺴـﻜﻮب اﻟﻜﺒـ ﺟـﺪ اً اﻟﺘـﺎﺑﻊ ﻟﻠﻤﺮﺻـﺪ اﻷوروﺑﻲ اﻟﺠﻨﻮﺑﻲ ﰲ ﻣﺠﺮة ﺑﻌﻴﺪة ﺟﺪ اً ﺑﺤﻴﺚ ﻳﺴـﺘﻐﺮق ﺿـﻮءه ﺛﻤﺎﻧﻴ ـﺔ ﻣﻠﻴ ـﺎرات ﺳـﻨﺔ ﻟﻠﻮﺻﻮل ﻳ. ﺎ إﻟﻴﻨ ﻌﺪ اﻟﺘﺪﻓﻖ اﻟﺮادﻳﻮي اﻟﴪﻳﻊ أﻳﻀ ﺎً ا واﺣﺪ ﻣﻦ أﻛﺜﺮ اﻟﺪﻓﻘﺎت ﻧﺸﺎﻃ ﺎً اﻟﺘﻲ ﺗﻢ رﺻﺪﻫﺎ ﻋﲆ اﻹﻃﻼق ، ﻓ ﻔﻲ ﺟﺰء ﺻﻐ ﻣﻦ اﻟﺜﺎﻧﻴﺔ أﻃﻠﻘﺖ ﻣﺎ ﻳﻌﺎدل إﺟﻤﺎﱄ اﻧﺒﻌﺎﺛﺎتﺷﻤﺴﻨﺎ ﻋﲆ ﻣﺪار ٣٠ . ﻋﺎﻣًﺎ ﺗﻢ اﻛﺘﺸﺎف اﻟﺘﺪﻓﻖ FRB 2022-0610A ﰲ ﻳﻮﻧﻴ ـﻮ ﻣ ـﻦ اﻟﻌ ـﺎم ا ـﺎﴈ ﺑﻮاﺳ ـﻄﺔ اﻟﺘﻠﺴﻜﻮب اﻟﺮادﻳـﻮي ASKAP ﰲ أﺳـﱰاﻟﻴﺎ وﺣﻄـﻢ رﻗ ـﻢ اﻟﻔﺮﻳ ـﻖ اﻟﻘﻴ ـﺎﳼ اﻟﺴــﺎﺑﻖ ﻟﻠﻤﺴــﺎﻓﺔ ﺑﻨﺴــﺒﺔ 50% ﺛــﻢ اﺳــﺘﺨﺪﻣﻨﺎ اﻟﺘﻠﺴـﻜﻮب اﻟ ﻜﺒـ ﺟـﺪ اً اﻟﺘـﺎﺑﻊ ﻟﻠﻤﺮﺻـﺪ اﻷوروﺑﻲ اﻟﺠﻨـﻮﺑﻲ ﰲ ﺗﺸـﻴﲇ ﻟﻠﺒﺤـﺚ ﻋـﻦ ا ﺠﺮة ا ﺼﺪر ووﺟﺪﻧﺎ أﻧﻬﺎ أﻗﺪم وأﺑﻌﺪ ﻣـﻦ أي ﻣﺼﺪر ﻟﺘﺪﻓﻖ رادﻳﻮي آﺧـﺮ ﺗـﻢ اﻟﻌﺜـﻮر ﻋﻠﻴـﻪ ﺣﺘـﻰ اﻵن وﻣـﻦ ا ﺤﺘﻤـﻞ أن ﺗﻜـﻮن ﺿـﻤﻦ ﻣﺠﻤﻮﻋ ـﺔ ﺻـﻐ ة ﻣـﻦ ا ﺠـﺮات ا ﻨﺪﻣﺠﺔ ". ﻳﺆﻛﺪ ﻫﺬا اﻻﻛﺘﺸﺎف أﻧـﻪ ﻳﻤﻜـﻦ اﺳـﺘﺨﺪام اﻟﺪﻓﻘﺎت اﻟﺮاد ﻳﻮﻳﺔ اﻟ ـ ﴪﻳﻌﺔ ﻟﻘﻴﺎ س ا ـﺎدة " ا ﻔﻘﻮدة " ﺑ ا ﺠﺮات ﻣﻤﺎ ﻳﻮﻓﺮ ﻃﺮﻳﻘـﺔ ﻟﻮزن " ﺟﺪﻳﺪة اﻟﻜﻮن " . إن اﻟﻄـﺮق اﻟﺤﺎﻟﻴـﺔ ﻟﺘﻘـﺪﻳﺮ ﻛﺘﻠـﺔ اﻟﻜـﻮن ﺗﻌﻄﻲ إﺟﺎﺑﺎت ﻣﺘﻀﺎرﺑﺔ وﺗﺘﺤﺪى اﻟﻨﻤـﻮذج اﻟﻘﻴﺎﳼ ﻟﻌﻠﻢ اﻟﻜﻮﻧﻴﺎت . ﻳﻘـﻮل رﻳـﺎن ﺷـﺎﻧﻮن اﻷﺳـﺘﺎذ ﰲ ﺟﺎﻣﻌـﺔ ﺳﻮﻳﻨﺒ ن ﺟﺎﻣﻌﺔ اﻟﺘﻜﻨﻮﻟﻮﺟﻴﺎ ﰲ أﺳـﱰاﻟﻴﺎ ــ واﻟﺬي ﺷﺎرك أﻳﻀًﺎ ﰲ ﻗﻴـﺎدة اﻟﺪراﺳـﺔ إذا »: أﺣﺼﻴﻨﺎ ﻛﻤﻴﺔ ا ﺎدة اﻟﻄﺒﻴﻌﻴـﺔ ﰲ اﻟﻜـ -ﻮن اﻟﺬرات اﻟﺘﻲ ﻧﺘﻜﻮن ﻣﻨﻬﺎ ﺟﻤﻴﻌ -ﺎ ﻓﺴـﻨﺠﺪ أن أﻛﺜﺮ ﻣـﻦ ﻧﺼـﻒ ﻣـﺎ ﻳﻨﺒﻐـﻲ أن ﻳﻜـﻮن اً ﻣﻮﺟﻮد اﻟﻴﻮم ﻣﻔﻘﻮد ."«اً ﻧﻌﺘﻘﺪ أن ا ﺎدة ا ﻔﻘﻮدة ﻣﺨﺘﺒﺌﺔ ﰲ اﻟﻔﻀﺎء ﺑ ا ﺠﺮات ﻟﻜﻨﻬﺎ ﻗﺪ ﺗﻜﻮن ﺳـﺎﺧﻨﺔ ﺟـﺪ اً ـ وﻣﻨﺘ ﴩة ﻟﺪرﺟﺔ أن ﻣﻦ ا ﺴﺘﺤﻴﻞ رؤﻳﺘ ﻬـﺎ ﺑﺎﺳﺘﺨﺪام اﻟﺘﻘﻨﻴﺎت اﻟﻌﺎدﻳﺔ ". إن ﺗﺪﻓﻘﺎت اﻟﺮادﻳﻮ ـ اﻟـ ﻳﺔ ﴪﻳﻌﺔ ﺗﺴﺘﺸـﻌﺮ ﻫﺬه ا ﺎدة ا ﺘﺄﻳﻨﺔ . ﻳﻘـﻮل ﺷـﺎﻧﻮن :» ﺣﺘـﻰ ﰲ اﻟﻔﻀـﺎء ﺷـﺒﻪ اﻟﻔــﺎرغ ﺗﻤﺎﻣــ ﺎً ﻳﻤﻜﻨﻬــ ﺎ رؤﻳــﺔ ﺟ ﻤﻴــﻊ اﻹﻟﻜﱰوﻧﺎت وﻫﺬا ﻳﺴﻤﺢ ﻟﻨﺎ ﺑﻘﻴﺎس ﻛﻤﻴـﺔ اﻷﺷﻴﺎء ا ﻮﺟﻮدة ﺑ ا ﺠﺮات . ﻳﻌﺪ اﻟﻌﺜـﻮر ﻋﲆ اﻟﺪﻓﻘﺎت اﻟﺮادﻳﻮﻳﺔ اﻟـ ـ اﻟﺒﻌﻴـﺪة ﴪﻳﻌﺔ أﻣـﺮ اً أﺳﺎﺳـﻴ ﺎً ﻟﻘﻴـﺎ س ا ـﺎدة ا ﻔﻘـﻮدة ﰲ اﻟﻜﻮن ﺑﺪﻗﺔ ﻛﻤﺎ أوﺿﺢ ﻋﺎﻟﻢ اﻟﻔﻠﻚ اﻷﺳﱰاﱄ اﻟﺮاﺣﻞ ﺟﺎن ﺑﻴ ﻣـﺎﻛﻮارت ﰲ ﻋـﺎم 2020 . » أﻇﻬﺮ ﺟﺎن ﺑﻴـ أﻧـﻪ ﻛﻠﻤـﺎ ﻛـﺎن اﻟﺘـﺪﻓﻖ اﻟﺮادﻳﻮي اﻟ اً ﴪﻳﻊ ﺑﻌﻴـﺪ ﻛﻠﻤـﺎ زاد اﻧﺘﺸـﺎر اﻟﻐﺎز ﺑ ا ﺠﺮات ﻳُ . ﻌﺮف ﻫـﺬا اﻵن ﺑﺎﺳـﻢ ﻋﻼﻗﺔ ﻣﺎﻛﻮارت وﻳﺒﺪو أن ﺑﻌﺾ اﻟﺘـﺪﻓﻘﺎت اﻟﺮادﻳﻮ ـاﻟ ﻳﺔ ﴪﻳﻌﺔ اﻷﺧ ة ﻛﺴـﺮت ﻫـﺬه اﻟﻌﻼﻗﺔ . ﻳﻘﻮل راﻳﺪر : " ﺗﺆﻛـﺪ ﻗﻴﺎﺳـﺎﺗﻨﺎ أن ـــ أن ﻋﻼﻗﺔ ﻣﺎﻛﻮارت ﺗﻤﺘﺪ إﱃ ﻣ ﺎ ﻫﻮ أﺑﻌﺪ ﻣﻦ ﻧﺼﻒ اﻟﻜﻮن ا ﻌﺮوف " . ﻳﻘﻮل ﺷـﺎﻧﻮن ﰲ :" ﺣ أﻧﻨﺎ ﻣـﺎ زﻟ ﻨـﺎ ﻻ ﻧﻌـﺮف أﺳـﺒﺎب ﻫـﺬه اﻟﺘﺪﻓﻘﺎت اﻟﻬﺎ ﺋﻠﺔ ﻣﻦ اﻟﻄﺎﻗﺔ ﺆﻛﺪ ﻳ اﻟﺒﺤـﺚ أن اﻟﺘﺪﻓﻘﺎت اﻟﺮادﻳﻮﻳﺔ اﻟﴪﻳﻌﺔ ﻫﻲ أﺣﺪاث ﺷﺎﺋﻌﺔ ﰲ اﻟﻜـﻮن وﺳـﻨﻜﻮن ﻗـﺎدرﻳﻦ ﻋـﲆ اﺳﺘﺨﺪاﻣﻬﺎ ﻟﻠﻜﺸﻒ ﻋﻦ ا ﺎدة ﺑ ا ﺠـﺮات وﻓﻬﻢ اﻟﺒﻨﻴﺔ ﺑﺸﻜﻞ أﻓﻀﻞ . ﺗﻤﺜـﻞ اﻟﻨﺘﻴﺠـﺔ اﻟﺤﺪ اﻷﻗﴡ ﺎ ﻳﻤﻜﻦ ﺗ ﺤﻘﻴﻘﻪ ﺑﺎﺳـﺘﺨﺪام اﻟﺘﻠﺴـﻜﻮﺑﺎت اﻟ ﻴ ـﻮم ﻋــﲆ اﻟ ـﺮﻏﻢ ﻣ ـﻦ أن اﻟﻔﻠﻜﻴ ﺳﻴﻤﺘﻠﻜﻮن ﻗﺮﻳﺒﺎً اﻷدوات اﻟﻼزﻣـﺔ ﻛﺘﺸﺎف ﻻ اﻟﺘﺪﻓﻘﺎت اﻷﻗﺪم واﻷﺑﻌﺪ وﺗﺤﺪﻳـﺪ ﺎ ﻣﺼ درﻫﺎ وﻗﻴﺎس ا ﺎدة ا ﻔﻘﻮدة ﰲ اﻟﻜﻮن . ﻳﻘﻮم ﻣﺮﺻﺪ ﻣﺼـﻔﻮﻓﺔ اﻟﻜﻴﻠـﻮﻣﱰ ا ﺮﺑـﻊ اﻟﺪوﱄ ﺎً ﺣﺎﻟﻴ ﺑﺒﻨﺎء ﺗﻠﺴـﻜﻮﺑ رادﻳـﻮﻳ ﰲ ﺟﻨﻮب إﻓﺮﻳﻘﻴﺎ وأﺳﱰاﻟﻴﺎ ﺳﻴﻜﻮﻧﺎن ﻗﺎدرﻳﻦ ﻋــﲆ اﻛﺘﺸـﺎف آﻻ ﺘـف اﻟ ﺪﻓﻘﺎت اﻟﺮادﻳﻮﻳـﺔ ﺗﺸـﻤﻞ ﺗﻠـﻚ اﻟﺒﻌﻴـﺪة ﺟـﺪ اً اﻟﺘـﻲ ﻻ ﻳﻤﻜـﻦ اﻛﺘﺸﺎﻓﻬﺎ ﺑﺎﺳﺘﺨﺪام ا ﻨﺸﺂ ت اﻟﺤﺎﻟﻴﺔ . إن اﻟﺘﻠﺴﻜﻮب اﻟﻜﺒ ﻟﻠﻐﺎﻳﺔ اﻟﺘﺎﺑﻊ ﻟﻠﻤﺮﺻﺪ اﻷوروﺑـﻲ اﻟ ﺠﻨـﻮﺑﻲ اﻟﺒـﺎﻟﻎ 39 اً ﻣـﱰ ﻗﻴـﺪ اﻹ ﻧﺸﺎء ﰲ ﺻﺤﺮاء أﺗﺎﻛﺎﻣﺎ اﻟﺘﺸﻴﻠﻴﺔ ﺳﻴﻜﻮن اﺣﺪ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﻘﻠﻴﻠﺔ اﻟﻘﺎدرة ﻋﲆ دراﺳﺔ ا ﺠﺮات ﻣﺼﺎدر و اﻟﺘﺪﻓﻘﺎت اﻷﺑﻌﺪ ﻣﻦ ﺣﺘﻰ اﻟﺘﺪﻓﻖ اﻟﺮادﻳﻮي FRB 20220610A . - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 4