Free Astronomy Magazine July-August 2024 ARABIC VERSION

historically been obscured. Looking closer toward the center, small specks depicted in green denote concentrated areas of iron, most of which are supernova remnants. Small patches that appear red sig- nify regions where molecular hy- drogen is being lit up by a nearby young star’s radiation. “This image shows the power of Webb,” said Rebecca Levy, second author of the study at the University of Arizona in Tucson. “Every single white dot in this image is either a star or a star cluster. We can start to distinguish all of these tiny point sources, which enables us to acquire an accurate count of all the star clusters in this galaxy.” Looking at M82 in slightly longer in- frared wavelengths, clumpy tendrils represented in red can be seen ex- tending above and below the gal- axy’s plane. These gaseous streamers are a galactic wind rushing out from the core of the starburst. One area of focus for this research team was understanding how this galactic wind, which is caused by the rapid rate of star formation and subse- quent supernovae, is being launched and in- fluencing its surround- ing environment. By resolving a central section of M82, scien- tists could examine where the wind origi- nates, and gain insight on how hot and cold components interact within the wind. Webb’s NIRCam instrument was well-suited to trace the structure of the galactic wind via emission from sooty chemical molecules known as polycyclic aromatic hydrocarbons (PAHs). PAHs can be considered as very small dust grains that survive in cooler temperatures but are de- stroyed in hot conditions. Much to the team’s surprise, Webb’s view of the PAH emission highlights the galactic wind’s fine structure – an aspect previously unknown. De- picted as red filaments, the emission extends away from the central re- gion where the heart of star forma- tion is located. Another unantici- pated find was the similar structure between the PAH emission and that of hot, ionized gas. “It was unexpected to see the PAH emission resemble ionized gas,” said Bolatto. “PAHs are not supposed to live very long when exposed to such a strong radiation field, so perhaps they are being replenished all the time. It challenges our theories and shows us that further investigation is required.” Webb’s observations of M82 in near- infrared light spur further questions about star formation, some of which the team hopes to answer with ad- ditional data gathered with Webb, including that of another starburst galaxy. Two other papers from this team characterizing the stellar clus- ters and correlations among wind components of M82 are almost fi- nalized. In the near future, the team will have spectroscopic observations of M82 from Webb ready for their analysis, as well as complementary large-scale images of the galaxy and wind. Spectral data will help as- tronomers determine accurate ages for the star clusters and provide a sense of timing for how long each phase of star formation lasts in a starburst galaxy environment. On a broader scale, inspecting the activity in galaxies like M82 can deepen astronomers’ understanding of the early universe. “Webb’s ob- servation of M82, a target closer to us, is a reminder that the telescope excels at studying galaxies at all dis- tances,” said Bolatto. “In addition to looking at young, high-redshift gal- axies, we can look at targets closer to home to gather insight into the processes that are happening here – events that also occurred in the early universe.”     31 رﺻــــﺪت ﻣﺠــــﺮة اﻻﻧﻔﺠــــﺎر اﻟﻨ ﻤــــﻲ M82 ﺑﻮاﺳــــﻄﺔ ﺗﻠﺴــــ ﻮبﻫﺎﺑــــﻞ ﻓــــﻲﻋــــﺎم 2006 أﻇﻬــــــﺮ ﻗــــــﺮص اﻟﻤﺠــــــﺮة اﻟــــــ واﻟــــــ ـ ــــــﺪروﺟ ﺤﻠﺰوﻧﻲواﻟﺴــــــﺤﺐ اﻟﻤﻤﺰﻗــــــﺔ وﻏــــــﺎزاﻟﻬ ـﺐ ﻗﻠـﺐ اﻟﺴﺎﺧﻦ وﻗﺪ رﺻﺪ ﺗﻠﺴ ﻮبﺟ ﻤﺲو M82 واﻟـﺘﻘﻂ ﺘﻔﺎﺻـﻴﻞ ﻏـ ﻣﺴـﺒﻮﻗﺔ ﻨ ــــــﺪ اﻟﻨﺠـــــﻮم ـــــﺔ وﻋﻨﺎﻗ ـــــﺔ اﻟﺮ ـــــﺎح اﻟﻤﺠﺮ ــــــﺔ وﺣـــــﺪد ﺧﺼــــــﺎﺋﺺ اﻟﻨﺠـــــﻮم اﻟﻔﺮد اﻟ. ﺼــــــﻮرة اﻟﺘﻘﻄــﺖ ﺑﻮاﺳــﻄﺔ أداة ـﺎم ﻧ ) ـﺎﻣ ا اﻷﺷــﻌﺔ ﺗﺤــﺖ اﻟــ ـ ــﺔ ﻤﺮاء اﻟﻘﺮ ( ﺗﺘﺘﺒـﻊ اﻟــ ـ ﺨﻴﻮط ــﺪروﻛﺮﻮﻧﺎت اﻟﻌﻄﺮ ــﺔ ﻣﺘﻌــﺪدة ــﺎرد ﻟﻠﺮ ــﺎح اﻟﻤﺠﺮ ــﺔ ﻋــ اﻟﻬ ــﻮن اﻟ ا ﻤــﺮاء ﺷــ ﻞ اﻟﻤ ـاﻟ ﺤﻠﻘﺎت وﻫﻲ ﻋ ﺎرة ﻋﻦ ﺣﺒﻴ ﺎت ﻏ ﺎر ﻘﺔ دﻗ ﺟﺪاً ﺗﺼﻤﺪ ﻓﻲ درﺟـﺎت اﻟـ ـ ـﺎردة ﺤﺮارة اﻟ وﻟﻜــﻦ ــﺘﻢ ﺗــﺪﻣ ﻫﺎ ﻓــﻲ اﻟﻈــﺮوف اﻟــ ـ . ﺤﺎرة ــﺔ ا إن ﻨ ــﺔ اﻟﻐــﺎزاﻟﻤﺘــﺄﻳﻦ ﻻﻧ ﻌــﺎث ﺗﺸــ ﮫ ﻨ ـﺪروﻛﺮﻮﻧﺎت اﻟﻌﻄﺮ ـﺔ ﻣﺘﻌـﺪدة اﻟـ ـﺪ اﻟﻬ ـﺔ ﺗﺠﺪ ﻣﻤﺎ ﺸ إﻟـﻰ إﻣ ﺎﻧ ـ ﺤﻠﻘﺎت ﻣـﻦ ﻣـﺎدة ﺟﺰ ﺌ ﺔ أﻛ ﺑﺮودة أﺛﻨﺎء ﺗﺄ ﻨﻬﺎ . ] NASA, ESA, CSA, STScI, Alberto Bolatto (UMD [( 31 - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 4 وﺑﺎﻟﻨﻈﺮ ﻧﺤﻮ ا ﺮﻛﺰ ﺗﺸ اﻟﺒﻘﻊ اﻟﺼـﻐ ة ا ﻮﺿﺤﺔ ﺑﺎﻟﻠﻮن اﻷﺧﴬ إﱃ ﻣﻨﺎ ﻃﻖ ﻣﺮﻛﺰة اﻟﺤﺪﻳﺪ ﻣﻦ وﻣﻌﻈﻤﻬﺎ ﻣـﻦ ﺑﻘﺎﻳـﺎ ا ﺴـﺘﻌﺮ اﻷﻋﻈﻢ . ﺗﺸ اﻟﺒﻘﻊ اﻟﺼﻐ ة اﻟﺘـﻲ ﺗﻈﻬـﺮ ﺑﺎﻟﻠﻮن اﻷﺣﻤﺮ إﱃ ا ﻨﺎﻃﻖ اﻟﺘﻲ ﻳﴤء ﻓﻴﻬـﺎ اﻟﻬﻴﺪروﺟ اﻟﺠﺰﻳﺌﻲ ﺑﻮاﺳﻄﺔ إﺷﻌﺎع ﻧﺠﻢ . ﺷﺎب ﻗﺮﻳﺐ ﻗﺎﻟﺖ رﻳﺒﻴﻜﺎ ﻟﻴﻔﻲ ا ﺆﻟﻔﺔ اﻟﺜﺎﻧﻴﺔ ﻟﻠﺪراﺳﺔ ﰲ ﺟﺎﻣﻌﺔ أرﻳﺰوﻧﺎ ﰲ ﺗﻮﻛﺴﻮن " : ﺗﻈﻬـﺮ ﻫـﺬه اﻟﺼﻮرة ﻗﻮة ﺗﻠﺴﻜﻮب ﻓ وﻳـﺐ ﻜـﻞ ﻧﻘﻄـﺔ ﺑﻴﻀﺎء ﰲ ﻫﺬه اﻟﺼـﻮرة ﻫـﻲ إﻣـﺎ ﻧﺠـﻢ أو ﻋﻨﻘﻮد ﻧﺠﻤﻲ و ﻳﻤﻜﻨﻨـﺎ أن ﻧﺒـﺪأ ﰲ اﻟﺘﻤﻴﻴـﺰ ﺑ ﻛﻞ ﻫﺬه ا ﺼﺎدر اﻟﻨﻘﻄﻴﺔ اﻟﺼﻐ ة اﻟﺘﻲ ﺗﻤﻜﻨﻨﺎ ﻣﻦ اﻟﺤﺼـﻮل ﻋـﲆ إﺣﺼـﺎء دﻗﻴـﻖ ﻟﺠﻤﻴﻊ اﻟﻌﻨﺎﻗﻴﺪ اﻟﻨﺠﻤﻴﺔ ﰲ ﻫﺬه ا ﺠﺮة . ﻋﻨﺪ اﻟﻨﻈﺮ إﱃ ا ﺠﺮة M82 ﺑﺄﻃﻮال ﻣﻮﺟﻴـﺔ أ ﻃﻮل ﻗﻠﻴﻼ ﻣﻦ اﻷﺷﻌﺔ ﺗﺤﺖ ا ﻟﺤﻤﺮاء ﻳﻤﻜﻦ رؤﻳﺔ ا ﺤ ﺎﻟﻴﻖ ا ﺘﻜﺘﻠﺔ ا ﻤﺜﻠﺔ ﺑﺎﻟﻠﻮن اﻷﺣﻤﺮ وﻫﻲ ﺗﻤﺘﺪ ﻓﻮق ﻣﺴﺘﻮى ا ﺠﺮة وﺗﺤﺘﻪ . ﻫﺬه اﻟﻼﻓﺘﺎت اﻟﻐﺎزﻳﺔ ﻋﺒﺎرة ﻋﻦ رﻳـﺎح ﻣﺠﺮﻳـﺔ ﺗﻨﺪﻓﻊ ﻣﻦ ﻗﻠﺐ اﻻﻧﻔﺠﺎر اﻟﻨﺠﻤﻲ . ﻟﻘﺪ ﻛﺎن أﺣﺪ ﻣﺠﺎﻻت اﻟﱰﻛﻴﺰ ﻟﻔﺮﻳﻖ اﻟﺒﺤﺚ ﻫﺬا ﻫﻮ ﻓﻬﻢ ﻛﻴﻔﻴﺔ إﻃـﻼق ﻫـﺬه اﻟﺮﻳـﺎح ا ﺠﺮﻳـﺔ اﻟﻨﺎﺗﺠﺔ ﻋﻦ ا ﻌﺪل اﻟﴪﻳﻊ ﻟﺘﻜﻮﻳﻦ اﻟﻨﺠـﻮم وا ﺴﺘﻌﺮات اﻟﻌﻈﻤﻰ اﻟﻼﺣﻘﺔ وﺗﺄﺛ ﻫﺎ ﻋﲆ اﻟﺒﻴﺌﺔ ا ﺤﻴﻄﺔ ﺑﻬﺎ . اﻟﺒﻴﺌـﺔ ا ﺤﻴﻄـﺔ ﺑﻬـ ﺎ وﻣـﻦ ﺧﻼل ﺣﻞ ﻗﺴﻢ ﻣﺮﻛﺰي ﻣـﻦ ا ﺠﺮة M82 ﻳﻤ ﻜﻦ ﻟﻠﻌﻠﻤـﺎء ﻓﺤﺺ ﻣﻜﺎن ﻧﺸـﻮء اﻟﺮﻳـﺎح واﻟﺤﺼﻮل ﻋﲆ ﻧﻈﺮة ﺛﺎﻗﺒـﺔ ﺣﻮل ﻛﻴﻔﻴﺔ ﺗﻔﺎﻋﻞ ا ﻜﻮﻧﺎت اﻟﺴ ـﺎﺧﻨﺔ واﻟﺒ ـﺎردة داﺧ ـﻞ اﻟﺮﻳﺎح . ﻟﻘﺪ ﻛﺎﻧﺖ أداة ) ﻧ ﻛـﺎم ( اﻟﺨﺎﺻـﺔ ﺑﺘﻠﺴﻜﻮب وﻳﺐ ﻣﻨﺎﺳﺒﺔ ﺗﻤﺎﻣ ﺎً ﻟﺘﺘﺒـﻊ ﺑﻨﻴـﺔ اﻟﺮﻳ ـﺎح ا ﺠﺮﻳ ـﺔ ﻋ ـﱪ اﻧﺒﻌ ـﺎث ﺟﺰﻳﺌ ـﺎت ﻛﻴﻤﻴﺎﺋﻴـــﺔ ﺳـــﺨﺎﻣﻴﺔ ﺗُﻌـــﺮف ﺑﺎﺳـــﻢ اﻟﻬﻴﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳﺔ ﻣﺘﻌﺪدة اﻟﺤﻠﻘﺎت ﻳﻤﻜﻦ اﻋﺘﺒـﺎر اﻟﻬﻴـﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳـ ﺔ ﻣﺘﻌﺪدة اﻟﺤﻠﻘﺎت ﻋﺒﺎرة ﻋﻦ ﺣﺒﻴﺒـﺎت ﻏﺒـﺎر ﺻﻐ ة ﺟﺪًا ﺗﺒﻘﻰ ﻋﲆ ﻗﻴﺪ اﻟﺤﻴﺎة ﰲ درﺟﺎت اﻟﺤـﺮارة اﻟﺒـﺎردة وﻟﻜـﻦ ﻳـﺘﻢ ﺗـﺪﻣ ﻫﺎ ﰲ اﻟﻈﺮوف اﻟﺤﺎرة . إن ﻣﻤﺎ أﺛﺎر دﻫﺸﺔ اﻟﻔﺮﻳﻖ ﻫﻮ ﺗﻤﻜﻦ ﺗﻠﺴﻜﻮب وﻳﺐ ﻣﻦ رؤﻳﺔ ﻻﻧﺒﻌﺎث اﻟﻬﻴﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳﺔ ا ﺘﻌﺪدة اﻟﺤﻠﻘﺎت ﺗﺴﻠﻂ اﻟﻀﻮء ﻋﲆ اﻟﺒﻨﻴـﺔ اﻟﺪﻗﻴﻘـ ﺔ ﻟﻠﺮﻳـﺎح ا ﺠﺮﻳﺔ وﻫﻮ ﺟﺎﻧﺐ ﻟﻢ ﻳﻜـﻦ ﻣﻌﺮوﻓًـﺎ ﻣـﻦ . ﻗﺒﻞ ﻳﻤﺘﺪ اﻻﻧﺒﻌﺎث اﻟ ﺬي ﺗﻢ ﺗﺼـﻮﻳﺮه ﻋـﲆ ﺷﻜﻞ ﺧﻴﻮط ﺣﻤـﺮاء ﺑﻌﻴـﺪ اً ﻋـﻦ ا ﻨﻄﻘـﺔ اﻟﻮﺳﻄﻰ ﺣﻴﺚ ﻳﻘﻊ ﻗﻠﺐ ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم . ﻣﻦ اﻻﻛﺘﺸﺎﻓﺎت اﻷﺧﺮى ﻏ ا ﺘﻮﻗﻌﺔ وﺟﻮد ﺑﻨﻴﺔ ﻣﻤﺎﺛﻠﺔ ﺑ اﻧﺒﻌـﺎث اﻟﻬﻴـﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳﺔ ا ﺘﻌﺪدة اﻟﺤﻠﻘﺎت واﻧﺒﻌـ ﺎث اﻟﻐـﺎز اﻟﺴﺎﺧﻦ ا ﺘﺄﻳﻦ . ﻗﺎل ﺑﻮﻻﺗﻮ " : ﻛﺎن ﻣﻦ ﻏـ ا ﺘﻮﻗـﻊ رؤﻳـﺔ اﻧﺒﻌﺎث اﻟﻬﻴﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳﺔ ا ﺘﻌـﺪ دة اﻟﺤﻠﻘـﺎت ﻳﺸـﺒﻪ اﻟﻐـﺎز ا ﺘـﺄﻳﻦ إﺿـﺎﻓﺔ ﻻ ﻳﻔﱰض أن ﺗﺼﻤﺪ اﻟﻬﻴﺪروﻛﺮﺑﻮﻧﺎت اﻟﻌﻄﺮﻳﺔ ﻣﺘﻌﺪدة اﻟﺤﻠﻘﺎت ﻟﻔﱰة ﻃﻮﻳﻠﺔ ﻋﻨﺪ ﺗﻌﺮﺿﻬﺎ ﺜﻞ ﻫﺬا ا ﺠﺎل اﻹﺷﻌﺎﻋﻲ اﻟﻘﻮي ﻟﺬ ﻟﻚ رﺑﻤﺎ ﻳﺘﻢ ﺗﺠﺪﻳﺪﻫﺎ ﻃﻮال اﻟﻮﻗـﺖ وذﻟـﻚ ﻳﺘﺤـﺪى ﻧﻈﺮﻳﺎﺗﻨﺎ وﻳﻈﻬـﺮ ﻟﻨـﺎ أن ﻫﻨـﺎك ﺣﺎﺟـﺔ إﱃ ﻣﺰﻳﺪ ﻣﻦ اﻟﺘﺤﻘﻴﻖ ”. ﺗﺜ أرﺻﺎد ﺗﻠﺴﻜﻮب وﻳﺐ ﻟ ﻠﻤﺠﺮة M82 ﰲ ﺿﻮء اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء اﻟﻘﺮﻳﺒﺔ ا ﺰﻳـﺪ ﻣﻦ اﻷﺳﺌﻠﺔ ﺣﻮل ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم واﻟﺘﻲ ﻳﺄﻣﻞ اﻟﻔﺮﻳﻖ ﰲ اﻹﺟﺎﺑﺔ ﻋﲆ ﺑﻌﻀـﻬﺎ ﻣـ ﻦ ﺧـﻼل اﻟﺒﻴﺎﻧﺎت اﻹﺿﺎﻓﻴﺔ اﻟﺘﻲ ﺟﻤﻌ ﺖ ﺑﺎﺳـﺘﺨﺪام ﺗﻠﺴﻜﻮب وﻳﺐ ﺑﻤﺎ ﰲ ذﻟـﻚ ﺑﻴﺎﻧـﺎت ﻣﺠـﺮة اﻧﻔﺠﺎر ﻧﺠﻤﻲ أﺧﺮى . ﺗﻢ ﺗﻘﺮﻳﺒ ﺎً اﻻﻧﺘﻬـﺎء ﻣـﻦ ورﻗﺘـ ﺑﺤﺜﻴﺘـ أﺧﺮﻳ ﻣﻦ ﻫﺬا اﻟﻔﺮﻳﻖ ﺗﺼﻔﺎن اﻟﺘﺠﻤﻌـﺎت اﻟﻨﺠﻤﻴﺔ واﻟﻌﻼﻗ ﺎت ا ﺘﺒﺎدﻟﺔ ﺑـ ﻣﻜﻮﻧـﺎت اﻟﺮﻳﺎح ﰲ ا ﺠﺮة . M82 ﻗﺮﻳﺒﺎً ﺳﻴﻜﻮن ﻟﺪى اﻟﻔﺮﻳﻖ أرﺻـﺎد ﻃﻴﻔﻴـﺔ ﻟ ﻠﻤﺠﺮة M82 ﻣﻦ ﺗﻠﺴـﻜﻮب وﻳـﺐ ﺟـﺎﻫﺰة ﻟﺘﺤﻠﻴﻠﻬﺎ وﻛـﺬﻟﻚ ﺻـﻮر ﺗﻜﻤﻴﻠﻴـﺔ واﺳـﻌﺔ اﻟﻨﻄﺎق ﻟﻠﻤﺠﺮة واﻟﺮﻳﺎح . ﺳﺘﺴﺎﻋﺪ اﻟﺒﻴﺎﻧﺎت اﻟﻄﻴﻔﻴـﺔ ﻋـﲆ ﺗﺤﺪﻳ ـﺪ اﻷﻋﻤ ـﺎر اﻟﺪﻗﻴﻘ ـﺔ ﻟﻠﻌﻨﺎﻗﻴ ـﺪ اﻟﻨﺠﻤﻴ ـﺔ وﻣﻌﺮﻓ ـﺔ ا ـﺪة اﻟﺘ ـﻲ ﺗ ﺴﺘﻐﺮﻗﻬﺎ ﻛﻞ ﻣﺮﺣﻠﺔ ﻣﻦ ﻣﺮاﺣـﻞ ﺗﻜـﻮﻳﻦ اﻟﻨﺠﻮم ﰲ ﺑﻴﺌﺔ ا ﺠﺮات اﻟﻨﺠﻤﻴـﺔ و ﻓﺤـﺺ اﻟﻨﺸـﺎط ﰲ ﻣﺠـﺮات ﻣﺜـﻞ M82 ﻳﻤﻜـﻦ أن ﻳﻌﻤﻖ ﻓﻬﻢ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻟﻠﻜﻮن ا ﺒﻜﺮ . ﻗﺎل ﺑﻮﻻﺗﻮ " : إن رﺻﺪ وﻳـﺐ ﻟ ﻠﻤﺠـﺮة M82 ﺗﺬﻛ ﺑـﺄن اﻟﺘﻠﺴـﻜﻮب ﻳﺘﻔـﻮق ﰲ دراﺳـﺔ ا ﺠﺮ ات ﻋـﲆ ﺟﻤﻴـﻊ ا ﺴـﺎﻓﺎت وﻣﺮاﻗﺒـﺔ ا ﺠﺮات اﻟ ﺸﺎﺑﺔ ذا ت اﻻﻧﺰﻳﺎح اﻷﺣﻤﺮ اﻟﻌـﺎﱄ ﻳﻤﻜﻨﻨﺎ ﻣﻦ رﺻـﺪ أﻫـﺪاف أﻗـﺮب وﻣﻌﺮﻓـﺔ ﻟﻠﻌﻤﻠﻴﺎت اﻟﺘﻲ ﺣﺪﺛﺖ ﰲ اﻟﻜﻮن ا ﺒﻜﺮ ."