Free Astronomy Magazine July-August 2024 ARABIC VERSION

Webb probes an extreme starburst galaxy by NASA/ESA/CSA − Abigail Major & Christine Pulliam team of astronomers has used NASA’s James Webb Space Telescope to survey the starburst galaxy Messier 82 (M82). Located 12 million light-years away in the constellation Ursa Ma- jor, this galaxy is relatively compact in size but hosts a frenzy of star formation activity. For comparison, M82 is sprouting new stars 10 times faster than the Milky Way galaxy. Led by Alberto Bolatto at the Uni- versity of Maryland, College Park, the team directed Webb’s NIRCam (Near-Infrared Camera) instrument toward the starburst galaxy’s center, attaining a closer look at the physi- cal conditions that foster the forma- tion of new stars. “M82 has garnered a variety of ob- servations over the years because it can be considered as the prototypi- cal starburst galaxy,” said Bolatto, lead author of the study. “Both NASA’s Spitzer and Hubble space telescopes have observed this tar- get. With Webb’s size and resolu- tion, we can look at this star-form- ing galaxy and see all of this beau- tiful, new detail.” Star formation continues to main- tain a sense of mystery because it is shrouded by curtains of dust and gas, creating an obstacle in observ- ing this process. Fortunately, Webb’s ability to peer in the infrared is an asset in navigating these murky con- ditions. Additionally, these NIRCam images of the very center of the starburst were obtained using an in- strument mode that prevented the very bright source from overwhelm- ing the detector. While dark brown tendrils of heavy dust are threaded throughout M82’s glowing white core even in this in- frared view, Webb’s NIRCam has re- vealed a level of detail that has " ﺐو" ﺴﺘﻜﺸﻒﻣﺠﺮة اﻧﻔﺠﺎر ﻧ ﻤﻲﻋﻨ ﻒ : ﻘﻠﻢ ﺑﻮﻟ ﺎم أﺑﻴﺠﻴﻞ ﻣﻴﺠﻮروﻛﺮﺴﺘ – و ﺎﻟﺔ ﻧﺎﺳﺎ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻷوروﺑ ﺔ / و ﺎﻟﺔ اﻟﻔﻀﺎء اﻟﻜﻨﺪ ﺔ اﺳـﺘﺨﺪم ﻓﺮﻳﻖ ﻣﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﺗﻠﺴﻜﻮب ﺟﻴﻤﺲ وﻳﺐ اﻟﻔﻀﺎﺋﻲ اﻟﺘﺎﺑﻊ ﻟﻨﺎﺳﺎ ﻹﺟﺮاء ا ﺴﺢ ﺠﺮة اﻻﻧﻔﺠﺎر اﻟﻨﺠﻤﻲ ﻣﻴﺴـﻴﻴﻪ 82 )M82 .( ﺗﻘـﻊ ﻫـﺬه ا ﺠـﺮة ﻋـﲆ ﺑﻌـﺪ 12 ﻣﻠﻴﻮن ﺳ ﻨﺔ ﺿﻮﺋﻴﺔ ﰲ ﻛﻮﻛﺒﺔ اﻟـﺪب اﻷﻛـﱪ وﻫﻲ ذات ﺣﺠﻢ ﻣﻀـﻐﻮط ﻧﺴـﺒﻴﺎً وﻟﻜﻨﻬـﺎ ﺗﺴﺘﻀـﻴﻒ ﻣﻮﺟـﺔ ﻣﺤﻤﻮﻣـﺔ ﻣـﻦ ﻧﺸـﺎط ﺗﻜﻮﻳﻦ اﻟﻨﺠﻮم . وﻋﲆ ﺳﺒﻴﻞ ا ﻘﺎرﻧـﺔ، ﻓـﺈن M82 ﺗﻨﺒﺖ ﻧﺠﻮﻣـﺎ ﺟﺪﻳـﺪة أﴎع ﺑﻌـ ﴩ ـ ﻣﺮات ﻣﻦ ﻣﺠﺮة درب اﻟﺘﺒﺎﻧﺔ . ﺑﻘﻴﺎدة أﻟﱪﺗﻮ ﺑﻮﻻﺗﻮ ﻣﻦ ﺟﺎﻣﻌﺔ ﻣ ﻳﻼﻧﺪ ﻛﻮﻟﻴـﺪج ﺑـﺎرك ﻗﺎم اﻟﻔﺮﻳـﻖ ﺑﺘﻮ أداة ﺟﻴـﻪ ﺗﺴـﻠﻜﻮب وﻳـﺐ ﻧ ﻛـﺎم ) ﻛـﺎﻣ ا اﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء اﻟﻘﺮﺑﻴﺔ ( ﻧﺤﻮ ﻣﺮﻛﺰ ا ﺠﺮة اﻟﻨﺠﻤﻴﺔ ﻹﻟﻘـﺎء ﻧﻈﺮة ﻓﺎﺣﺼﺔ ﻋﲆ اﻟﻈﺮوف اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﺘﻲ ﺗﻌﺰز ﺗﺸﻜﻴﻞ ا ﺠﺮات اﻟﺠﺪﻳﺪة . اﻟﻨﺠﻮم . ﻧﻈﺮة ﻓﺎﺣﺼﺔ ﻋﲆ اﻟﻈﺮوف اﻟﻔﻴﺰﻳﺎﺋﻴﺔ اﻟﺘﻲ ﺗﻌﺰز ﺗﺸﻜﻴﻞ اﻟﻨﺠﻮم اﻟﺠﺪﻳﺪة . ﻗـﺎل ﺑﻮﻻﺗـﻮ ا ﺆﻟﻒ اﻟﺮﺋ ﻴﴘـ ﻟﻠﺪراﺳـﺔ " : ﻟﻘـﺪ ﺣﺼـﻠﺖ ا ﺠﺮة M82 ﻋـﲆ ﻣﺠﻤﻮﻋـﺔ ﻣﺘﻨﻮﻋـﺔ ﻣـﻦ اﻷرﺻﺎد ﻋﲆ ﻣﺮ اﻟﺴﻨ ﻷﻧﻪ ﻳﻤﻜﻦ اﻋﺘﺒﺎرﻫﺎ ﻣﺠﺮة ﻧﻤﻮذﺟﻴﺔ ﻟﻼﻧﻔﺠﺎر اﻟﻨﺠﻤﻲ ." ﻟ ﻘﺪ رﺻﺪ ﻛﻞ ﻣﻦ اﻟﺘﻠﺴـﻜﻮﺑ اﻟﻔﻀـﺎﺋﻴ ﺳﺒﻴﺘﺰر وﻫﺎﺑﻞ اﻟﺘﺎﺑﻌ ﻟﻨﺎﺳﺎ ﻫﺬا اﻟﻬـﺪف . ﺑﻔﻀﻞ ﺣﺠﻢ ﺗﻠﺴﻜﻮب وﻳﺐ ودﻗﺘﻪ ﻳﻤﻜﻨﻨـﺎ أن ﻧﻨﻈﺮ إﱃ ﻫﺬه ا ﺠﺮة اﻟﺘﻲ ﺗﺘﺸـﻜﻞ ﻓﻴﻬـﺎ اﻟﻨﺠﻮم وﻧﺮى ﻛﻞ ﻫﺬه اﻟﺘﻔﺎﺻﻴﻞ اﻟﺠﻤﻴﻠﺔ . ﻻ ﻳـﺰال ﺗﺸـﻜﻞ اﻟﻨﺠـﻮم ﻳﺤــﺘﻔﻆ ﺑﺤـﺲ اﻟﻐﻤﻮض ﻷ ﻧﻪ ﻣﺤﺎط ﺑﺴـﺘﺎﺋﺮ ﻣـﻦ اﻟﻐﺒـﺎر واﻟﻐﺎز ﻣﻤﺎ ﻳﺸﻜﻞ ﻋﺎﺋﻘﺎً أﻣﺎم ﻣﺮاﻗﺒﺔ ﻫـﺬه اﻟﻌﻤﻠﻴﺔ . وﻟﺤﺴﻦ اﻟﺤﻆ، ﻓﺈن ﻗﺪرة وﻳﺐ ﻋﲆ اﻟﻨﻈﺮ ﰲ اﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ﺗﻌـﺪ ﻣﻴـﺰة ﻣﻔﻴﺪة ﰲ اﻟﺘﻨﻘﻞ ﰲ ﻫﺬه اﻟﻈﺮوف اﻟﻐﺎﻣﻀﺔ . اﻟﻌﻤﻠﻴﺔ وﻟﺤﺴﻦ اﻟﺤﻆ ﻓﺈن ﻗﺪرة ﺗﻠﺴﻜﻮب وﻳﺐ ﻋﲆ اﻟﻨﻈﺮ ﰲ اﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء ﺗﻌﺪ ﻣﻴﺰة ﻫﺎﻣﺔ و ﻣﻔﻴﺪة ﰲ اﻟﺘﻨﻘـﻞ ﰲ ﻫـﺬه اﻟﻈﺮوف اﻟﻐﺎﻣﻀﺔ . ﺑﺎﻹﺿﺎﻓﺔ إﱃ ذﻟﻚ ﺗﻢ اﻟﺤﺼﻮل ﻋـﲆ ﺻـﻮر ﻧ ﻛﺎم ) ﻛﺎﻣ ا ﺮ ( ﻛـﺰ اﻻﻧﻔﺠـﺎر اﻟﻨﺠﻤـﻲ ﺑﺎﺳﺘﺨﺪا م أداة ﺗ ﻤﻨﻊ ا ﺼﺪر اﻟﺴﺎﻃﻊ ﺟـﺪ اً ﻣﻦ إﻏﺮاق اﻟﻜﺎﺷﻒ . ﺑﻴﻨﻤﺎ ﺗﻨﺘﴩ ﺧﻴﻮط ﺑﻨﻴﺔ داﻛﻨﺔ ﻣـﻦ اﻟﻐﺒـﺎر اﻟﺜﻘﻴﻞ ﰲ ﺟﻤﻴﻊ أﻧﺤـﺎء ﻗﻠـﺐ ا ﺠـﺮة M82 اﻷﺑــﻴﺾ ا ﺘــﻮﻫﺞ ﺣﺘــﻰ ﰲ ﻫـﺬه اﻟﺼـﻮرة ﺑﺎﻷﺷﻌﺔ ﺗﺤـﺖ اﻟﺤﻤـﺮاء، ﻛﺸـﻔﺖ ﻛـﺎﻣ ا ﻧ ﻛﺎم ﻋﻦ ﻣﺴﺘﻮى ﻣـﻦ اﻟﺘﻔﺎﺻـﻴﻞ ﻛﺎﻧـﺖ ﻣﺤﺠﻮﺑﺔ ﺗﺎ ".ﺎ رﻳﺨﻴ - ﻳﻮﻟﻴﻮ ﺃﻏﺴﻄﺲ 2 0 2 4