Free Astronomy Magazine November-December 2024 ARABIC VERSION

reveal new properties, both those that were previously predicted and maybe some that weren’t.” To show that they could make de- tections at 0.87 mm, the Collabora- tion conducted test observations of distant, bright galaxies at this wave- length. Rather than using the full EHTarray,theyemployedtwosmaller subarrays, both of which included ALMA and the Atacama Pathfinder EXperiment (APEX) in the Atacama DesertinChile.TheEuropeanSouth- ernObservatory(ESO)isapartnerin ALMA and co-hosts and co-operates APEX. Other facilities used include the IRAM 30-meter telescope inSpain and the NOrthern Extended Millimeter Array (NOEMA) in France, as well as the Greenland Telescope andtheSubmillimeterArrayin Hawai ‘ i. Inthispilotexperiment,theCollab- oration achieved observations with detailasfineas19microarcseconds, meaning they observed at the high- est-ever resolution from the surface of Earth. They have not been ableto obtain images yet, though: while theymaderobustdetectionsof light from several distant galaxies, not enough antennas were used tobe able to accurately reconstruct an image from the data. Thistechnicaltesthasopenedupa new window to study black holes. With the full array, the EHT could seedetailsassmallas13microarc- seconds,equivalenttoseeingabot- tle cap on the Moon from Earth. This means that, at 0.87 mm, they will be able to get images with a resolution about 50% higher than that of previously released M87* and SgrA* 1.3-mm images. In addi- tion, there’s potential to observe more distant, smaller and fainter blackholesthanthetwotheCollab- oration has imaged thus far. EHT Founding Director Sheperd “Shep” Doeleman, an astrophysicist at the CfA and study co-lead, says: “Looking at changes in the sur- rounding gas at different wave- lengths will help us solve the mystery of how black holes attract and accrete matter, and how they canlaunchpowerfuljetsthatstream over galactic distances.” This is the first time that the VLBI technique has been successfully used at the 0.87 mm wavelength. While the ability to observe the nightskyat0.87mmexistedbefore the new detections, using the VLBI techniqueatthiswavelengthhasal- ways presented challenges that took time and technological ad- vances to overcome. For example, watervapourintheatmosphereab- sorbswavesat0.87mmmuchmore than it does at 1.3 mm, making it more difficult for radio telescopes to receive signals from black holes at the shorter wavelength. Combined with increasingly pro- nounced atmospheric turbulence and noise buildup at shorter wave- lengths, and an inability to control global weather conditions during atmospherically sensitive observa- tions, progress to shorter wave- lengths for VLBI — especially those that cross the barrier into the sub- millimetreregime—hasbeenslow. But with these new detections, that’s all changed. “TheseVLBIsignaldetectionsat0.87 mm are groundbreaking since they open a new observing window for the study of supermassive black holes” ,statesThomasKrichbaum,a co-authorofthestudyfromtheMax Planck Institute for Radio Astron- omyinGermany,aninstitutionthat operates the APEX telescope to- gether with ESO. He adds: “In the future, the combination of the IRAM telescopes in Spain (IRAM- 30m) and France (NOEMA) with ALMA and APEX will enable imag- ingofevensmallerandfainteremis- sionthanhasbeenpossiblethusfar attwowavelengths,1.3mmand 0.87mm, simultaneously.”     ﺗﺸ اﻟﻨﻘﺎ ط اﻟﺼﻔﺮاء ﻓﻲ ﻫﺬﻩ اﻟـ ﻟ ﺨﺮﻄﺔ ﻠﻌﺎﻟﻢ إﻟﻰﻣﻮﻗﻊ اﻟﻬﻮاﺋ ﺎت و ﺷﺎرﻛﺖ ﻓﻲ اﻟﻤﺼﻔﻮﻓﺎت اﻟ اﻻﺧﺘ ﺎر اﻟﺘﺠﺮ اﻟﺬ أﺟﺮاﻩ ﻣﺸﺮوع ﺗﻠﺴ ﻮب أﻓﻖ ـ اﻟـ . ﺤﺪث ــﺎن اﻻ ــﺎر ﻮﻫـ ﺧﺘ ـﺎ ــﺔ ﻗ ﺗـﻢ ﻓﻴﻬــﺎ اﺳـﺘﺨﺪام ﺗﻘﻨ اﻟﻤــﺮة اﻷوﻟــﻰ اﻟــ س اﻟﺘــﺪاﺧﻞ اﻷﺳﺎﺳــ ﺔ اﻟﻄﻮ ﻠــﺔ ﺟـﺪاً اﻟﺘﻠﺴـ ﻮ ﺎت اﻟــ ﺗــﺮﻂ ﺑـ واﻟــ ﺗ ﻌــﺪ ﻣﺌــﺎت أو آﻻف اﻟﻜ ﻠـﻮﻣ ات ﻨﺠـﺎح ﻟ ﺮﺻـﺪ اﻟﻀـﻮء ﻄـﻮل ﻣﻮﺟـﺔ ﻳ ﻠـﻎ 0.87 . ﻣـﻢ ﻣـﻦ ﺧـﻼل رﺻـﺪ اﻟﻀـ ﻮء ﻋﻨـﺪ ﻫـﺬا اﻟﻄـﻮل اﻟﻤـﻮﺟﻲ اﻟﻤـﻨﺨﻔﺾ ـﺎﺣﺜﻮ ﻣﺸـﺮوع ﺗﻠﺴــ ﻮب ﺗﻤﻜـﻦ أﻓــﻖ اﻟــ ـ ﺤﺪث ﻣــﻦ اﻟــ ـ ﺤﺼﻮل ﻋﻠــﻰ أرﺻــﺎد ﺪﻗــﺔ أﻋﻠــﻰ ﺣﺼــﻠﻮا ﻋﻠﻴﻬــﺎ ﻣــﻦ ﻗﺒــﻞ ﻣــﻦ ﺗﻠــﻚ اﻟــ ـ دون اﻟــ ــﻮﻳﻦ ﺗﻠﺴــ ﻮب أﻛــ ﺤﺎﺟﺔ إﻟــﻰ ﺗ . ﺗﺘﻤﺘــﻊ اﻻ ﺗــﻢ ﻛﺘﺸــﺎﻓﺎت اﻟــ إﺟﺮاؤﻫﺎ ﺄﻋﻠﻰدﻗﺔ ﺗﻢ اﻟ ـ ﺤﺼﻮل ﻋﻠﻴﻬﺎ ﻋﻠﻰ اﻹﻃﻼق ﻣﻦﺳﻄﺢ اﻷرض ] . ESO/M. Kornmesser [ ﻧﻮﻓﻤﺒﺮ - ﺩﻳﺴﻤﺒﺮ 2 0 2 4 ﻷﻧﻨﺎ ﻛﻨﺎ ﻋﻨﺪ اﻟﺤـﺪود ا ﻄﻠﻘـﺔ ـﺪى ﺣـﺪة اﻟﺼـﻮر اﻟﺘ ـﻲ ﻳﻤﻜﻨﻨ ـﺎ اﻟﺘﻘﺎﻃﻬ ـﺎ واﻵ ن ﰲ ﻣﺨﺘﱪ اﻟﺪﻓﻊ اﻟﻨﻔﺎث وﻛﻼﻫﻤـﺎ ﰲ اﻟﻮﻻﻳـﺎت ا ﺘﺤﺪة . ﻋﻨﺪ 0.87 ﻣﻢ ﺳﺘﻜﻮن ﺻﻮرﻧﺎ أﻛﺜﺮ ﺗﻔﺼـﻴﻼً ﻣﻤ ـﺎ ﻗ ـﺪ ﻳﻜﺸ ـﻒ ﺑ ـﺪوره ﻋ ـﻦ ﺧﺼﺎﺋﺺ ﺟﺪﻳﺪة ﻟﻜﻠ ﻤﻦ ﺗﻠﻚ اﻟﺘﻲ ﺗﻢ اﻟﺘﻨﺒﺆ ﺑﻬﺎ ﻣﺴﺒﻘﺎً ورﺑﻤﺎ ﺑﻌﻀـﻬﺎ ﻟـﻢ ﻳـﺘﻢ اﻟﺘﻨﺒـﺆ ."ﺑﻬﺎ ﻹﺛﺒﺎت ﻗﺪرﺗﻬﻢ ﻋﲆ إﺟـﺮاء ﻋﻤﻠﻴـﺎت اﻛﺘﺸﺎف ﻋﻨـﺪ 0.87 ﻣـﻢ أﺟـﺮى اﻟﺘﻌـﺎون أ رﺻــﺎداً اﺧﺘﺒﺎرﻳــﺔ ﻟﻠﻤﺠــﺮات اﻟﺒﻌﻴــﺪة اﻟﺴﺎﻃﻌﺔ ﻋﻨﺪ ﻫﺬا اﻟﻄﻮل ا ﻮﺟﻲ ﺑـﺪﻻً ﻣـﻦ اﺳ ـﺘﺨﺪام ﻣﺠﻤﻮﻋــﺔ ﺗﻠﺴ ـﻜﻮب اﻳﻔﻴﻨــﺖ ﻫﻮراﻳﺰون اﻟﻜﺎﻣﻠﺔ اﺳﺘﺨﺪﻣﻮا ﻣﺠﻤـﻮﻋﺘ ﻓﺮﻋﻴﺘ أﺻﻐﺮ ﺣﺠﻤﺎ ﺗﻀﻤﻨﺖ ﻛﻞ ﻣﻨﻬﻤـﺎ ﻣﺮﺻـﺪ أ ـﺎ و ﺗﺠﺮﺑـﺔ ﻣﺴﺘﻜﺸـﻒ أﺗﺎﻛﺎﻣـﺎ أﺑـﻴﻜﺲ ) ( ﰲ ﺻـﺤﺮاء أﺗﺎﻛﺎﻣـﺎ ﰲ ﺗﺸـﻴﲇ . ا ﺮﺻﺪ اﻷوروﺑـﻲ اﻟﺠﻨـﻮﺑ ﻲ ﻫـﻮ ﴍﻳـﻚ ﰲ ﻣﺮﺻﺪ أ ﺎ وﻳﺴﺘﻀﻴﻒ وﻳﺘﻌﺎون ﻣﻊ ﺗﺠﺮﺑـﺔ أﺑﻴﻜﺲ ) ( ﺗﺸﻤﻞ ا ﺮاﻓﻖ اﻷﺧﺮى ا ﺴﺘﺨﺪﻣﺔ ﺗﻠﺴﻜﻮب إرام) ( ﺑﻘﻄﺮ 30 ﻣـﱰاُ ﰲ إﺳـﺒﺎﻧﻴﺎ وﻣﺼـﻔﻮﻓﺔ ا ﻠﻴﻤــﱰ اﻟﺸـﻤﺎﻟﻴﺔ ا ﻮﺳــﻌﺔ ( ﻧﻮﻳﻤﺎ ) ﰲ ﻓﺮﻧﺴﺎ ﺑﺎﻹﺿـﺎﻓﺔ إﱃ ﺗﻠﺴـﻜﻮب ﻏﺮﻳﻨﻼﻧــﺪ وﻣﺼــﻔﻮﻓﺔ ﺗﺤــﺖ ا ﻠﻴﻤــﱰ ﰲ . ﻫﺎواي ﻟﻘﺪ ﺗﻤﻜﻦ ﻓﺮﻳـﻖ اﻟﺘﻌـﺎون ﰲ ﻫـﺬه اﻟﺘﺠﺮﺑﺔ ﻣﻦ إﺟﺮاء أرﺻﺎد ﺑﺘﻔﺎﺻﻴﻞ ﺗﺼـﻞ إﱃ 19 ﻣﻴﻜﺮوﺛﺎﻧﻴﺔ ﻗﻮﺳﻴﺔ ﻣﻤﺎ ﻳﻌﻨﻲ أﻧﻬـﻢ رﺻﺪوا ﺑﺄﻋﲆ دﻗﺔ ﻋﲆ اﻹﻃﻼق ﻣـﻦ ﺳـﻄﺢ اﻷرض وﻟﻢ ﻳﺘﻤﻜﻨﻮا ﻣﻦ اﻟﺤﺼﻮل ﻋﲆ ﺻﻮر ﺣﺘـﻰ اﻵن ﻋـﲆ اﻟـﺮﻏﻢ ﻣـﻦ أﻧﻬـﻢ ﻗـﺎﻣﻮا ــــــــ ﺑﺎﻛﺘﺸﺎﻓﺎ ت ﻗﻮﻳﺔ ﻟﻠﻀﻮء ﻣﻦ ﻋﺪة ﻣﺠـﺮات إﻻ أ ﺑﻌﻴﺪة ﻧﻬﻢ ﻟﻢ ﻳﺴﺘﺨﺪﻣﻮا ﻋﺪد اً ﺎً ﻛﺎﻓﻴ ﻣﻦ اﻟﻬﻮاﺋﻴﺎت ﻟﻴﻜﻮﻧﻮا ﻗﺎدرﻳﻦ ﻋﲆ إﻋـﺎدة ﺑﻨـ ﺎء ﺻﻮرة ﺑﺪﻗﺔ ﻣﻦ اﻟﺒﻴﺎﻧـﺎت . ﻟﻘـﺪ ﻓـﺘﺢ ﻫـﺬا اﻻﺧﺘﺒـﺎر اﻟﺘﻘﻨـﻲ ﻧﺎﻓـﺬة ﺟﺪﻳـﺪة ﻟﺪراﺳـﺔ اﻟﺜﻘـﻮب اﻟﺴـﻮداء . ﺑﺎﺳــ ﺘﺨﺪام ا ﺠﻤﻮﻋــﺔ اﻟﻜﺎﻣﻠﺔ ﻳﻤﻜﻦ ﻟ ﺘﻠﺴﻜﻮب اﻳﻔﻴﻨﺖ ﻫﻮراﻳﺰون رؤﻳـﺔ ﺗﻔﺎﺻـﻴﻞ ﺗﺼـﻞ إﱃ 13 ﻣﻴﻜﺮوﺛﺎﻧﻴـﺔ ﻗﻮﺳﻴﺔ وﻫﻮ ﻣﺎ ﻳﻌﺎدل رؤﻳ ﺔ ﻏﻄﺎء زﺟﺎﺟـﺔ ﻋﲆ اﻟﻘﻤﺮ ﻣﻦ اﻷرض وﻫﺬا ﻳﻌﻨﻲ أﻧـﻪ ﻋﻨـﺪ 0.87 ﻢﻣ ﺳﻴﻜﻮﻧﻮن ﻗﺎدرﻳﻦ ﻋﲆ اﻟﺤﺼـﻮل ﻋﲆ ﺻﻮر ﺑﺪﻗﺔ أﻋﲆ ﺑﻨﺤـﻮ 50 ٪ ﻣـﻦ دﻗـﺔ ﺻﻮر اﻟﺜﻘﺐ اﻷﺳﻮد M87 * و اﻟﺜﻘﺐ اﻷﺳـﻮد أ ﺳﺎﺟﻴﱰﻳﻮس * اﻟﺘﻲ ﺗﻢ إﺻـﺪارﻫﺎ ﺳـﺎﺑﻘًﺎ ﺑﺪﻗـﺔ 1.3 . ﻣـﻢ ﺑﺎﻹﺿـﺎﻓﺔ إﱃ ذﻟـﻚ ﻫﻨـﺎك إﻣﻜﺎﻧﻴﺔ ﻟﺮﺻﺪ ﺛﻘـ ﻮب ﺳـﻮداء أﻛﺜـﺮ ﺑﻌـﺪ اً وأﺻﻐﺮ ﺣﺠﻤ ﺎً وأﺿﻌﻒ ﻣﻦ اﻟﺜﻘﻮب اﻟﺴﻮداء اﻟﺘﻲ ﺻﻮرﻫﺎ اﻟﺘﻌﺎ ون ﺣﺘﻰ اﻵن . ﻳﻘـﻮل ﺷـﻴﱪد " ﺷــﻴﺐ " دوﻟﻴﻤ ـﺎن ا ـﺪﻳﺮ ا ﺆ ﺳﺲ ﻟ ﺘﻠﺴﻜﻮب اﻳﻔﻴﻨﺖ ﻫﻮراﻳﺰون وﻫﻮ ﻋــﺎﻟﻢ ﻓﻴﺰﻳ ـﺎء ﻓﻠﻜﻴــﺔ ﰲ ﻣﺮﻛــﺰ ﺳــﺎﻳﻨﺲ ﻓﻠﻮرﻧﺲ وا ﺸﺎرك ﰲ اﻟﺪراﺳﺔ " : إن اﻟﻨﻈﺮ إﱃ اﻟﺘﻐ ات ﰲ اﻟﻐﺎز ا ﺤﻴﻂ ﻋﻨﺪ أﻃﻮال ﻣﻮﺟﻴﺔ ﻣﺨﺘﻠﻔﺔ ﺳﻴﺴﺎﻋﺪﻧﺎ ﰲ ﺣﻞ ﻟﻐﺰ ﻛﻴﻔﻴﺔ ﺟﺬب اﻟﺜﻘﻮب اﻟﺴﻮداء ﻟﻠﻤـﺎدة وﺗﺮ اﻛﻤﻬـﺎ وﻛﻴـﻒ ﻳﻤﻜﻨﻬﺎ إﻃﻼق ﻧﻔﺎﺛﺎت ﻗﻮﻳـﺔ ﺗﺘـﺪﻓﻖ ﻋـﱪ ﻣﺴﺎﻓﺎت ﻣﺠﺮﻳﺔ ." ﻫﺬه ﻫﻲ ا ﺮة اﻷوﱃ اﻟﺘﻲ ﻳﺘﻢ ﻓﻴﻬﺎ اﺳﺘﺨﺪام ﺗﻘﻨﻴـﺔ ﻗﻴـ ﺎس اﻟﺘـﺪاﺧﻞ اﻷﺳﺎﳼ اﻟﻄﻮﻳﻞ ﺟﺪ ) اَ VLBI ( ﺑﻨﺠﺎح ﻋﻨـﺪ ﺗﻜﻨﻮﻟﻮﺟﻴًﺎ ﻟﻠﺘﻐﻠﺐ ﻋﻠﻴﻬﺎ . اﻟﻄـﻮل ا ـﻮﺟﻲ 0.87 ﻣـﻢ ﰲ ﺣـ ﻛﺎﻧـﺖ اﻟﻘﺪرة ﻋﲆ ﻣﺮاﻗﺒﺔ اﻟﺴﻤﺎء اﻟﻠﻴﻠﻴﺔ ﻋﻨﺪ 0.87 ﻣﻢ ﻣﻮﺟﻮدة ﻗﺒﻞ اﻻﻛﺘﺸﺎﻓﺎت اﻟﺠﺪﻳﺪة ﻓـﺈن اﺳﺘﺨﺪام ﺗﻘﻨﻴﺔ ﻗﻴﺎس اﻟﺘـﺪاﺧﻞ ﻋﻨـﺪ ﻫـﺬا اﻟ ﻄﻮل ا ـﻮ ﺟﻲ ﻛـﺎن ﻳﻤﺜـﻞ ﺎً داﺋﻤـ ﺗﺤـﺪﻳﺎ اﺳﺘﻐﺮق ﺎً وﻗﺘ ﺎً وﺗﻘﺪﻣ ﺗﻘﻨﻴﺎً ﻟﻠﺘﻐﻠـﺐ ﻋﻠﻴـﻪ . ﻋﲆ ﺳﺒﻴﻞ ا ﺜﺎل ﻳﻤﺘﺺ ﺑﺨﺎر ا ﺎء ﰲ اﻟﻐﻼف اﻟﺠﻮي ا ﻮﺟﺎت ﻋﻨﺪ 0.87 ﻣﻢ أﻛﺜـﺮ ﺑﻜﺜـ ﻣﻤﺎ ﻳﻔﻌﻞ ﻋﻨـﺪ 1,3 ﻣـﻢ ﻣﻤـﺎ ﻳﺠﻌـﻞ ﻣـﻦ اﻟﺼﻌﺐ ﻋﲆ اﻟﺘﻠﺴﻜﻮﺑﺎت اﻟﺮادﻳﻮﻳـﺔ ﺗﻠﻘـﻲ إﺷﺎرات ﻣﻦ اﻟﺜﻘﻮب اﻟﺴـﻮداء ﻋﻨـﺪ اﻟﻄـﻮل ا ﻮﺟﻲ ا و ﻷﻗﴫ ﺑﺎﻟﺘﺰاﻣﻦ ﻣﻊ اﻻﺿﻄﺮاﺑﺎت اﻟﺠﻮﻳﺔ ا ﺘﺰاﻳﺪة اﻟﻮﺿﻮح وﺗﺮا ﻛﻢ اﻟﻀﻮﺿﺎء ﻋﻨﺪ أﻃﻮال ﻣﻮﺟﻴﺔ أﻗﴫ وﻋﺪم اﻟﻘﺪرة ﻋﲆ اﻟﺘﺤﻜﻢ ﰲ اﻟﻈﺮوف اﻟﺠﻮﻳـﺔ اﻟﻌﺎ ﻴـﺔ أﺛﻨـﺎء ﻋﻤ ﻠﻴﺎت اﻟﺮﺻﺪ اﻟﺤﺴﺎﺳﺔ ﻟﻠﻐـﻼف اﻟﺠـﻮي ﻓﻘﺪ ﻛﺎن اﻟﺘﻘﺪم ﻧﺤﻮ أﻃﻮال ﻣﻮﺟﻴﺔ أﻗﺼ ﺮ ـ ﻟ ﺘﻘﻨﻴﺔ ﻗﻴﺎس اﻟﺘﺪاﺧﻞ وﺧﺎﺻﺔ اﻟﺘـﻲ ﺗﻌـﱪ اﻟﺤﺎﺟﺰ إﱃ ﻧﻈﺎم دون ا ﻠﻴﻤﱰ ﺑﻄﻴﺌ ﺎً وﻟﻜـﻦ ﺑ ﺎ ﻬﺬه اﻟﻜ ﺷﻔﺎت اﻟﺠﺪﻳﺪة ﺗﻐ ﻛﻞ ﳾء . ﻳﻘـﻮل ﺗﻮﻣـﺎس ﻛﺮﻳﺸـﺒﺎوم أﺣـﺪ ﻣـﺆﻟﻔﻲ اﻟﺪراﺳﺔ ﻣﻦ ﻣﻌﻬﺪ ﻣﺎﻛﺲ ﺑﻼﻧﻚ ﻟﻌﻠﻢ اﻟﻔﻠ ﻚ اﻟﺮادﻳــﻮي ﰲ أ ﺎﻧﻴ ـﺎ ": ﺗﻌﺘــﱪ اﻛﺘﺸــﺎﻓﺎت إﺷﺎرات ﻗﻴ ﺎس اﻟﺘﺪاﺧﻞ ﻣﻬﻤﺔ ﻷﻧﻬـﺎ ﺗﻔـﺘﺢ ﻧﺎﻓـﺬة ﺟﺪﻳـﺪة ﻟﺪراﺳـﺔ اﻟﺜﻘـﻮب اﻟ ﺴـﻮداء اﻟﻬﺎﺋﻠ ـﺔ و اﻟﺠﻤ ـﻊ ﺑــ ﻋـﺪة ﺗﻠﺴـﻜﻮﺑﺎت رادﻳﻮﻳﺔ ﺳﻣـﺎ ﻴﺴـﻤﺢ ﺑﺘﺼـﻮﻳﺮ اﻧﺒﻌﺎﺛـﺎ ت ﺑﻴﻨﻴﺔ أﺻﻐﺮ وأﺿﻌﻒ اﻟ ﻋﻨﺪ ا ﻄﻮﻟ ﻮﺟﻴ 1.3 ﻣﻢ و 0.87 ﻣﻢ ﰲ وﻗﺖ واﺣﺪ ."