Free Astronomy Magazine January-February 2023 ARABIC VERSION

nova we identified typical? How bright are these explosions? What types of galaxies do they occur in?” Existing telescopes can’t cover wide enough areas or observe deeply enough to find more distant ex- amples, but that will change with Roman. At this stage, LIGO leads the pack in identifying neutron star mergers. It can detect gravitational waves in all areas of the sky, but some of the most distant collisions may be too weak to be identified. Roman is set to join LIGO’s search, offering com- plementary qualities that help “fill out” the team. Roman is a survey telescope that will repeatedly scan the same areas of the sky. Plus, Roman’s field of view is 200 times larger than the Hubble Space Tele- scope’s infrared view – not as vast as LIGO’s, but huge for a telescope that takes images. Its cadence will allow researchers to spot when objects on the sky brighten or dim, whether nearby or very far away. Roman will provide researchers a powerful tool for observing ex- tremely distant kilonovae. This is due to the expansion of space. Light that left stars billions of years ago is stretched into longer, redder wave- lengths, known as infrared light, over time. Since Roman specializes in capturing near-infrared light, it will detect light from very distant ob- jects. How distant? “Roman will be able to see some kilonovae whose light has traveled about 7 billion years to reach Earth,” explained Eve Chase, a postdoctoral researcher at Los Alamos National Laboratory in Los Alamos, New Mexico. Chase led a more recent study that simulated how differences in kilono- vae ejecta can vary what we expect to observe from observatories in- cluding Roman. There’s a second benefit to near-in- frared light: It provides more time to observe these short-lived bursts. Shorter wavelengths of light, like ul- traviolet and visible, disappear from view in a day or two. Near-infrared light can be gathered for a week or more. Researchers have been simu- lating the data to see how this will work. “For a subset of simulated kilonovae, Roman would be able to observe some more than two weeks after the neutron star merger oc- curred,” Chase added. “It will be an excellent tool for looking at kilono- vae that are very far away.” Soon, researchers will know far more about where kilonovae occur, and how often these explosions occur in the history of the universe. Were those that occurred earlier dif- ferent in some way? “ Roman will allow the astronomy community to begin conducting population studies along with a slew of new analyses on the physics of these explosions,” Scolnic said. A survey telescope offers enormous possibility – and also a ton of data that will require precise machine learning. Astronomers are meeting this challenge by writing code to au- tomate these searches. Ultimately, Roman’s massive data sets will help researchers unravel perhaps the greatest mysteries about kilonovae to date: What happens after two neutron stars collide? Does it pro- duce a single neutron star, a black hole, or something else entirely? With Roman, we will gather the sta- tistics researchers need to make sub- stantial breakthroughs.     ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٢٨ ﻗﺎل داﻧ ﻴـﺎل إم ﺳـﻜﻮﻟﻨﻴﻚ اﻷﺳـﺘﺎذ ا ﺴـﺎﻋﺪ ﻟﻠﻔﻴﺰﻳﺎء ﰲ ﺟﺎﻣﻌﺔ دﻳﻮك ﰲ دورﻫـﺎم ﺑﻮﻻﻳـﺔ ﻧـﻮرث ﻛﺎروﻟﻴﻨـﺎ واﻟـﺬي ﻗـﺎد اﻟﺪر اﺳـﺔ ﻻ :" ﻧﻌﺮف ﺣﺘﻰ اﻵن ﻣﻌﺪل ﻫﺬه اﻷﺣـﺪاث وﻟﻜـﻦ ﻟﺪﻳﻨﺎ ﺗﻘﺪﻳﺮ ﻟﻌﺪد اﻧﻔﺠﺎرات اﻟﻜﻴﻠﻮﻧﻮﻓﺎ اﻟﺘـﻲ ﻳﻤﻜﻦ اﻧﻬﺎ اﻛﺘﺸﻔﺖ ﺑﻮاﺳﻄﺔ ا ﺮاﺻﺪ ا ﺎﺿﻴﺔ واﻟﺤﺎﻟﻴــﺔ وا ﺴ ـﺘﻘﺒﻠﻴﺔ . " ﻫــﻞ اﻟﻜﻴﻠﻮﻧﻮﻓ ـﺎ ا ﻨﻔﺮدة اﻟﺘﻲ ﺣﺪدﻧﺎﻫﺎ ﻧﻤﻮذﺟﻴﺔ؟ ﻣـﺎ ﻣـﺪى ﺳﻄﻮع ﻫـﺬه اﻻﻧﻔﺠـﺎرات؟ ﻣـﺎ ﻫـﻲ أﻧـﻮاع ا ﺠــﺮات اﻟﺘــﻲ ﺗﻮﺟــﺪ ﻓﻴ ﻬــﺎ؟ ﻻ ﻳﻤﻜــﻦ ﻟﻠﺘﻠﺴ ـﻜﻮﺑﺎت اﻟﺤﺎﻟﻴــﺔ ﺗﻐﻄﻴــﺔ ﻣﺴ ـﺎﺣﺎت واﺳﻌﺔ ﺑﻤﺎ ﻳﻜﻔـﻲ أو ا ﺮاﻗﺒـﺔ ﺑ ﻌﻤـﻖ ﻛـﺎفٍ ﻟﻠﻌﺜﻮر ﻋﲆ أﻣﺜﻠﺔ أﺑﻌﺪ وﻟﻜﻦ ﻫﺬا ﺳﻴﺘﻐ ﻣﻊ ﺗﻠﺴـﻜﻮب روﻣـﺎن اﻟﻔﻀـﺎﺋﻲ . ﺧـﻼل ﻫـﺬه ا ﺮﺣﻠﺔ ﻳﻘﻮد ﻣﺮﺻﺪ اﻷﻣﻮاج اﻟﺜﻘﺎﻟﻴﺔ ( ﻟﻴﻐﻮ ) ا ﺠﻤﻮﻋﺔ ﰲ ﺗﺤﺪﻳﺪ ﻋﻤﻠﻴﺎت اﻧـﺪﻣﺎج اﻟﻨﺠـﻮم اﻟﻨﻴﻮﺗﺮوﻧﻴﺔ . ﻳﻤﻜﻨﻪ اﻛ ﺘﺸﺎف ﻣﻮﺟﺎت اﻟﺜﻘﺎﻟﻴﺔ ﰲ ﺟﻤﻴﻊ ﻣﻨﺎﻃﻖ اﻟﺴـﻤﺎء وﻟﻜـﻦ ﻗـﺪ ﺗﻜـﻮن ﺑﻌﺾ اﻟﺘﺼﺎدﻣﺎت اﻷﺑﻌﺪ أﺿﻌﻒ ﻣﻦ أن ﻳـﺘﻢ ﺗﺤﺪﻳﺪﻫﺎ . ﻳﺴﺘﻌﺪ ﺗﻠﺴﻜﻮب روﻣﺎن اﻟﻔﺼﺎﺋﻲ ﻟﻼﻧﻀﻤﺎم إﱃ أﺑﺤﺎث ﻣﺮﺻﺪ اﻻﻣﻮاج اﻟﺜﻘﺎﻟﻴـﺔ ( ﻟﻴﻐﻮ ) ﺣﻴﺚ ﻳﻘﺪم ﺻﻔﺎت ﺗﻜﻤﻴﻠﻴـﺔ ﺗﺴـﺎﻋﺪ "ﻋﲆ ﺗﻮﻓ اﻟﺒﻴﺎﻧﺎت اﻟﺘﻲ ﻳﺤﺘﺎﺟﻬﺎ اﻟﻔﺮﻳﻖ " . ( روﻣﺎن ) ﻫﻮ ﺗ ﻠﺴﻜﻮب ﺳ ﻴﻘﻮم ﺑﻤﺴﺢ ﻧ ﻔﺲ ا ﻨﺎﻃﻖ ﻣﻦ اﻟﺴﻤﺎء ﺑﺸﻜﻞ ﻣﺘﻜﺮر ﺑﺎﻹﺿـﺎﻓﺔ إﱃ ذﻟﻚ ﻓﺈن ﻣﺠﺎل رؤﻳـﺔ ﺗﻠﺴـﻜﻮب روﻣـﺎن اﻟﻔﻀﺎﺋﻲ أﻛﱪ ﺑﻤﻘﺪار ٢٠٠ ﻣـﺮة ﻣـﻦ رؤﻳـﺔ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤ ﺮاء ﻟﻨﻄﺎق ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ ﻟﻜﻨﻪ ﻟﻴﺲ واﺳﻌًﺎ ﻣﺜ ﻞ ﻣﺮﺻﺪ اﻻﻣﻮاج اﻟﺜﻘﺎﻟﻴﺔ ( ﻟﻴﻐﻮ ) ﻟﻜﻨﻪ ﻳﻌﺘﱪ ﺿﺨﻢ ﺑﺎﻟﻨﺴﺒﺔ ﻟﺘﻠﺴﻜﻮب ﻳﻠـﺘﻘﻂ اﻟﺼـﻮر ﺣﻴـﺚ ﺳﻴﺴـﻤﺢ ﻟﻠﺒـﺎﺣﺜ ﺑﺘﺤﺪﻳـﺪ ﻣﺘـﻰ ﺗﺴـﻄﻊ أو ﺗﺨﻔـﺖ اﻷﺟﺴـﺎم ا ﻮﺟﻮدة ﰲ اﻟﺴﻤﺎء ﺳـﻮاء ﻛﺎﻧـﺖ ﻗﺮﻳﺒـﺔ أو ﺑﻌﻴﺪة ﺟﺪًا . ﺳﻴﻮﻓﺮ ﺗﻠﺴﻜﻮب روﻣﺎن ﻟﻠﺒﺎﺣﺜ أداة ﻗﻮﻳ ـﺔ ﺮاﻗﺒ ـﺔ اﻧﻔﺠ ـﺎر اﻟ ات ﻜﻴﻠﻮﻧﻮﻓ ـﺎ اﻟ ﺒﻌﻴﺪ ة ﻟﻠﻐﺎﻳﺔ ﻫﺬا ﺑﺴـﺒﺐ ﺗﻮﺳـﻊ اﻟﻔﻀـﺎء ﻓﺎﻟﻀﻮء اﻟـﺬي ﺗـﺮك اﻟﻨﺠـﻮم ﻗﺒـﻞ ﻣﻠﻴـﺎرات اﻟﺴـﻨ ﻳﺘﻤ ـﺪد إﱃ ﻣﻮﺟـﺎت أﻃـﻮل وأﻛﺜ ـﺮ اﺣﻤﺮارًا ﺗُﻌﺮف ﺑﺎﻟﻀﻮء ﺗﺤﺖ اﻷﺣﻤﺮ ﺑﻤـﺮور اﻟﻮﻗﺖ . ﻧﻈﺮًا ﻷن ﺗﻠﺴﻜﻮب روﻣﺎن اﻟﻔﻀـﺎﺋﻲ ﻣﺘﺨﺼﺺ ﰲ اﻟﺘﻘـﺎط ﺿـﻮء اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒﺔ ﻓﺴﻮف ﻳﻜﺘﺸﻒ اﻟﻀﻮء ﻣـﻦ اﻷ ﺟﺮام اﻟﺒﻌﻴﺪة ﺟﺪًا . أوﺿﺤﺖ إﻳـﻒ ﺗﺸـﻴﺲ ﺑﺎﺣﺜﺔ ﻣـﺎ ﺑﻌـﺪ اﻟـﺪﻛﺘﻮراه ﰲ ﻣﺨﺘـﱪ ﻟـ ﻮس أﻻﻣـﻮس اﻟـﻮﻃﻨﻲ ﰲ ﻟـﻮس أﻻﻣـﻮس ﰲ ﻧﻴـﻮ ﻣﻜﺴﻴﻜﻮ " : ﺳﻴﺘﻤﻜﻦ ﺗﻠﺴﻜﻮب روﻣـﺎن ﻣـﻦ رؤﻳﺔ ﺑﻌﺾ اﻧﻔﺠﺎرات اﻟ ﻜﻴﻠﻮﻧﻮﻓﺎ اﻟﺘﻲ ﺳﺎﻓﺮ ﺿﻮءﻫﺎ ﺣﻮاﱄ ٧ ﻣﻠﻴﺎرات ﺳـﻨﺔ ﻟﻠﻮﺻـﻮل إﱃ اﻷرض "، تﻗﺎد ﺗﺸﻴﺲ دراﺳﺔ أﺣﺪث ﺗﺤﺎﻛﻲ ﻛﻴﻒ ﻳﻤﻜﻦ ﻟﻼﺧﺘﻼﻓﺎت ﰲ ا ﺎدة ا ﻘﺬوﻓﺔ ﻣﻦ اﻧﻔﺠﺎر اﻟﻜﻴﻠﻮﻧﻮﻓﺎ أن ﺗﻐ ﻣﺎ ﻧﺘﻮﻗﻊ أن ﻧـﺮاه ﻣﻦ ا ﺮاﺻـ ﺪ ﺑﻤـﺎ ﰲ ذﻟـﻚ ﺗﻠﺴـﻜﻮب روﻣـﺎن اﻟﻔﻀﺎﺋﻲ ، ﻫﻨﺎك ﻓﺎﺋﺪة أﺧﺮى ﻟﻀﻮء اﻷﺷـﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒﺔ : ﻓﻬﻮ ﻳﻮﻓﺮ ﻣﺰﻳﺪًا ﻣـﻦ اﻟﻮﻗﺖ ﻟﺮﺻﺪ ﻫﺬه اﻟﺪﻓﻘﺎت ﻗﺼـ ة اﻟﻌﻤـﺮ . ﺗﺨﺘﻔﻲ اﻷﻃﻮال ا ﻮﺟﻴﺔ اﻷﻗﴫ ﻣـﻦ اﻟﻀـﻮء ﻣﺜﻞ اﻷﺷﻌﺔ ﻓﻮق اﻟﺒﻨﻔﺴﺠﻴﺔ وا ﺮﺋﻴـﺔ ﻋـﻦ اﻷﻧﻈـﺎر ﰲ ﻏﻀـﻮن ﻳـﻮم أو ﻳـﻮﻣ . ﻳﻤﻜـﻦ ﺗﺠﻤﻴ ﻊ ﺿﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒـﺔ ﺪة أﺳـﺒﻮع أو أﻛﺜـﺮ . ﻟﻘـﺪ ﻗـﺎم اﻟﺒـﺎﺣﺜﻮن ﺑﻤﺤﺎﻛﺎة اﻟﺒﻴﺎﻧﺎت ﻌﺮﻓﺔ ﻛﻴﻔﻴـﺔ ﻋﻤـﻞ ذﻟـﻚ أو ﺖﺿﺎﻓ ﺗﺸﻴﺲ : ﺑﺎﻟﻨﺴﺒﺔ ﺠﻤﻮﻋـﺔ ﻓﺮﻋﻴـﺔ ﻣﻦ ﻣﺤﺎﻛﺎة اﻟ ﻜﻴﻠﻮﻧﻮﻓـﺎ ﺳـﻴﻜﻮن ﺗﻠﺴـﻜﻮب روﻣﺎن ﻗﺎدرًا ﻋﲆ رﺻﺪ ﺑﻌﺾ ﻣﻨﻬﺎ ﺑﻌﺪ أﻛﺜـﺮ ﻣﻦ أﺳﺒﻮﻋ ﻣ ﻦ اﻧﺪﻣﺎج اﻟﻨﺠﻮم اﻟﻨﻴﻮﺗﺮوﻧﻴﺔ ﻴﺳ ﻜﻮن أداة ﻣﻤﺘﺎزة ﻟﻠﺒﺤﺚ ﻋـﻦ اﻟ ﻜﻴﻠﻮﻧﻮﻓـﺎ اﻟﺒﻌﻴﺪة ﺟﺪًا . ﻗﺮﻳﺒﺎً ﺳـﻴﻌﺮف اﻟﺒـﺎﺣﺜﻮن ﻋـﻦ ﻣﻜﺎن ﺣﺪوث اﻟﻜﻴﻠﻮﻧﻮﻓﺎ وﻋـﺪد ا ـﺮات اﻟﺘـﻲ ﺗ ﺤﺪث ﻓﻴﻬﺎ ﻫﺬه اﻻﻧﻔﺠﺎرات ﰲ اﻟﻜﻮن . ﺘــــﺎر ﺦ ١٧ أﻏﺴــــﻄﺲ ٢٠١٧ ــــﺔ اﻛﺘﺸــــﻒﻣﺮﺻــــﺪ ﻣﻮﺟــــﺎت اﻟﺜﻘﺎﻟ ﻟ ﻐــــﻮ ) ( ــــﺎس اﻟﺘــــﺪاﺧﻞ ﻻﻛﺘﺸــــﺎف وﻣﻘ ﻣﻮﺟﺎت اﻟﺜﻘﺎﻟ ﺔ اﺻﻄ ( ﻓ ﻏﻮ ) ﻧﻴـﻮﺗﺮوﻧﻴ ﻧ ﻤـ ﺪام ﺑ و. ﻓـﻲﻏﻀـﻮن ١٢ ﺳـﺎﻋﺔ ﺣـﺪدت اﻟﻤﺮاﺻـﺪ ـ ﻣﺼـﺪراﻟـ ﺤﺪث داﺧـﻞ اﻟﻤﺠـﺮة اﻟﻌﺪﺳـ ﺔ NGC 4993 ﺗـﻢ ﻤﻌﻬـﺎ اﻟﻤﻮﺿـﺤﺔ ﻓـﻲﻫـﺬﻩ اﻟﺼـﻮرة اﻟـ ﺎﺳـﺘﺨﺪام ﺗﻠﺴــ ﻮبﻫﺎﺑــﻞ اﻟﻔﻀـﺎﺋﻲ . إن اﻟﺘــﻮﻫﺞ اﻟﻨ ﻤــﻲ اﻟﻤﺼــﺎﺣﺐ ﻟــﮫ اﻧﻔﺠــﺎراﻟﻜ ﻠﻮﻧﻮﻓـﺎ ﻣﺮــﻲ ﺑﻮﺿﻮح ﻓﻲ أرﺻﺎد ﺗﻠﺴ ﻮبﻫﺎﺑﻞ . ﻻﺣﻆﻫﺎﺑﻞ أ ن ﻛ ﻠﻮﻧﻮﻓﺎ ﻳﺨﻔﺖ ﺗﺪر ﺠ ﺎً ﻋﻠﻰﻣﺪارﺳﺘﺔ أ ﺎم . ﻳﻨﺎﻳﺮ ﻓ اﻳﺮ 2023