Free Astronomy Magazine July-August 2022 ARABIC VERSION

of even more distant galaxies. The image was taken with one of the highest-performance wide-field imaging instruments in the world, the Dark Energy Camera (DECam). This instrument is perched atop the Víctor M. Blanco 4-meter Telescope and its vantage point allows it to collect starlight reflected by the telescope’s 4-meter-wide (13-foot- wide) mirror, a massive, aluminum- coated and precisely shaped piece of glass roughly the weight of a semi truck. After passing through the optical innards of DECam — including a corrective lens nearly a meter (3.3 feet) across — starlight is captured by a grid of 62 charge-coupled de- vices (CCDs). These CCDs are similar to the sensors found in ordinary digital cameras but are far more sensitive, and allow the instrument to create detailed images of faint astronomical objects such as NGC 1512 and NGC 1510. Large astronomical instruments such as DECam are custom-built masterpieces of optical engineer- ing, requiring enormous effort from astronomers, engineers, and technicians before the first images can be captured. Funded by the US Department of Energy (DOE) with contributions from international partners, DECam was built and tested at DOE’s Fermilab, where sci- ــــــﮫ ﺎﻟ ﻣﺠــــــﺮي رﺻــــــﺪ ــــــﺎﻣ ا ﺑ DECam أ ﻣﺎﻧﺪا ﻮﺗﺶ اﻟ ﻤﺨﺘ ﻟﺒﺤـﻮث اﻟﻔﻠـﻚ ﺎﻷﺷـﻌﺔ ﺗﺤـﺖ اﻟﻮﻃ ا ﻤﺮاء اﻟﻀﻮﺋ ﺔ ) NOIRLab ( ﰎ اﻟﺘﻘـــﺎط اﳌﺠـــﺮة اﳊﻠﺰوﻧﻴـــﺔ ذات اﻟﻘﻀـــﺒﺎن اﳌﺴﻤﺎة NGC 1512 ) ﻋـﲆ اﻟﻴﺴـﺎر ( وﺟﺎرﺗﻬـﺎ اﻟﺼﻐﲑة اﳌﺠﺮة NGC 1510 ﻫﺬا اﻟﺮﺻـﺪ ﺑﻮاﺳﻄﺔ ﺗﻠﺴﻜﻮب ﻓﻴﻜﺘﻮر إم ﺑﻼﻧﻜـﻮ اﻟﺒـﺎﻟﻎ ارﺑﻌﺔ أﻣﺘﺎر ﺑﺎﻹﺿﺎﻓﺔ إﱃ اﻟﻜﺸﻒ ﻋـﻦ اﻟﺒ ﻴـﺔ اﻟﺪاﺧﻠﻴﺔ اﳌﻌﻘـﺪة ﻟﻠﻤﺠـﺮة NGC 1512 ﺗُﻈﻬـﺮ ﻫـــﺬه اﻟﺼـــﻮرة اﳌﺤـــﻼق اﳋـــﺎرﴂ اﻟﻀـــﻌﻴﻒ ﻟﻠﻤﺠـــﺮة وﻫـــﻮ ﳝﺘـــﺪ وﻳﺒـــﺪو وﻛﺄﻧـــﻪ ﻳﺤـــﻴﻂ ﲟﺮاﻓﻘﺘﻬـﺎ اﻟﺼـﻐﲑة . إن ﺗﻴــﺎر اﻟﻀـﻮء اﳌﺮﺻــﻊ ﺑﺎﻟﻨﺠﻮم اﻟﺬي ﻳـﺮﺑﻂ ﺑـﲔ اﳌﺠـﺮﺗﲔ ﻫـﻮ دﻟﻴـﻞ ﻋـﲆ ﺗﻔﺎﻋـﻞ اﳉﺎذﺑﻴــﺔ ﺑﻴﻨﻬﻤـﺎ - ارﺗﺒــﺎط ﻓﺨـﻢ ورﺷﻴﻖ اﺳﺘ ﻣﻨﺬ ٤٠٠ ﻣﻠﻴﻮن ﺳﻨﺔ ﻟﻘـ . ﺪ أﺛـﺮ ﺗﻔﺎﻋـﻞ اﳉﺎذﺑﻴـﺔ ﺑـﲔ NGC 1512 و NGC 1510 ﻋــﲆ ﻣﻌــﺪل ﺗﺸــﻜﻞ اﻟﻨﺠــﻮم ﻛﻠﺘــﺎ اﳌﺠﺮﺗﲔ ﺑﺎﻹﺿﺎﻓﺔ إ ﱃ ﺗﺸﻮﻳﻪ أﺷـﻜﺎﻟﻬﻤﺎ . اﻟﻨﻬﺎﻳـﺔ ﺳـﻮف ﺗﻨـﺪﱅ NGC 1512 و NGC 1510 ﳎــﺮة واﺣــﺪة أﻛــ -ﱪ ﻣﺜــﺎل ﻣﻄــﻮل ﻟﺘﻄﻮر اﳌﺠﺮات ﻮﺗ . ﺟﺪ ﻫﺬه اﳌﺠﺮات اﳌﺘﻔﺎﻋﻠـﺔ اﺗﺠـــﺎه ﻛﻮﻛﺒـــﺔ ﻫﻮروﻟﻮﺟﻴـــﻮم ﻧﺼـــﻒ اﻟﻜــﺮة اﻟﺴــﻤﺎوﻳﺔ اﳉﻨﻮﺑﻴــﺔ وﺗﺒﻌــﺪ ﺣــﻮاﱄ ٦٠ ﻣﻠﻴــﻮن ﺳــﻨﺔ ﺿــﻮﺋﻴﺔ ﻋــﻦ اﻷرض . ﻻ ﻳُﻈﻬــﺮ ﳎﺎل اﻟﺮؤﻳﺔ اﻟﻮاﺳﻊ ﻫﺬه اﳌﺠـﺮات اﳌﺘﺸـﺎﺑﻜﺔ ﻓﺤﺴــﺐ ﺑــﻞ ﻳُﻈﻬــﺮ أﻳﻀًــﺎ ﳏﻴﻄﻬــﺎ اﳌﺮﺻــﻊ ﺑــﺎﻟﻨﺠﻮم . اﻹﻃــﺎر ﻣــﲇء ﺑــﺎﻟﻨﺠﻮم اﻷﻣﺎﻣﻴــﺔ اﻟﺴـــﺎﻃﻌﺔ داﺧـــﻞ ﳎـــﺮة درب اﻟﺘﺒﺎﻧـــﺔ ﻋـــﲆ ﺧﻠﻔﻴــﺔ ﻣـﻦ اﳌﺠـﺮات اﻷﻛـﱶ ﺑﻌــﺪً .ا ﰎ اﻟﺘﻘــﺎط اﻟﺼــﻮرة ﺑﻮاﺣــﺪة ﻣــﻦ أﻋــﲆ أدوات اﻟﺘﺼــﻮ ﻳﺮ ذات اﳌﺠــﺎل اﻟﻮاﺳــﻊ اﻟﻌــﺎﱂ وﻫــﻲ ﻛــﺎﻣﲑا اﻟﻄﺎﻗـﺔ اﳌﻈﻠﻤـﺔ اﳌﻄـﻮرة (DECam) اﳌﺜ ﺘـﺔ ﻋﲆ ........ ﻋـــﲆ ﺗﻠﺴـــﻜﻮب ﻓﻴﻜﺘـــﻮر إم ﺑﻼﻧﻜـــﻮ اﻟﺒـــﺎﻟﻎ أرﺑﻌﺔ أﻣﺘﺎر اﻟﺬي ﻳﺴﻤﺢ ﺑﺠﻤﻊ ﺿﻮء اﻟﻨﺠﻮم اﳌــﻨﻌﻜﺲ ﺑﻮاﺳـﻄﺔ ﻣـﺮآة اﻟﺘﻠﺴـﻜﻮب اﻟﺒـﺎﻟﻎ ﻋﺮﺿـــﻬ ﺎ ٤ أ ) ﻣﺘـــﺎر ١٣ ( ﻗـــﺪﻣًﺎ وﻫـــﻲ ﺿـــﺨﻤﺔ وﻣﻐﻄــﺎة ﺑــﺎﻷﳌﻨﻴﻮم وﺷــﻜﻠﻬﺎ دﻗﻴــﻖ ﻗﻄﻌــﺔ ﻣـــﻦ اﻟﺰﺟـــﺎج ﺗﻌـــﺎدل وزن ﻧﺼـــﻒ ﺷــــﺎﺣﻨﺔ ﺗﻘﺮﻳﺒًـــﺎ . ﺑﻌــﺪ اﳌــﺮور ﻋــﱪ اﻷﺟــﺰاء اﻟﺪاﺧﻠﻴــﺔ اﻟﻀــﻮﺋﻴﺔ ﻟ ) ﻜــﺎﻣﲑا DECam (- ﲟــﺎ ذﻟــﻚ اﻟﻌﺪﺳﺔ اﻟﺘﺼﺤﻴﺤﻴﺔ اﻟﱵ ﻳﺒﻠـﻎ ﻋﺮﺿـﻬﺎ ﻣـﱰًا ﺗﻘﺮﻳﺒًـــﺎ )٣.٣ -( ﻗـــﺪﻣًﺎ ﻳـــﺘﻢ اﻟﺘﻘـــﺎط ﺿــــﻮء اﻟﻨﺠﻮم ﺑﻮاﺳﻄﺔ ﺷﺒﻜﺔ ﻣﻜﻮﻧﺔ ﻣﻦ ٦٢ ﺟﻬـﺎزًا ﻣﻘﱰﻧًﺎ ﲟﺴ ﺸﻌﺮات ) CCDs ( ﺗﺘﺸﺎﺑﻪ أﺟﻬﺰة CCD) ( ﻣــــــﻊ اﳌﺴ ﺸـــــﻌﺮات اﳌﻮﺟـــــﻮدة اﻟﻜــﺎﻣﲑات اﻟﺮﻗﻤﻴــﺔ اﻟﻌﺎدﻳــﺔ وﻟﻜﻨﻬـــﺎ أﻛــﱶ ﺣﺴﺎﺳﻴﺔ ﺑﻜﺜﲑ ، وﺗﺴـﻤﺢ ﻟﻠﻜـﺎﻣﲑا ﺑﺈﻧﺸـﺎء ﺻــﻮر ﻣﻔﺼــﻠﺔ ﻟﻸﺟﺴـــﺎم اﻟﻔﻠﻜﻴـــﺔ اﳋﺎﻓﺘــﻪ ﻣﺜــﻞ NGC 1512 و NGC 1510 . اﻷدوات اﻟﻔﻠﻜﻴﺔ اﻟﻜﺒﲑ ة ﻣﺜﻞ ﻛﺎﻣﲑا ) DECam ( ﻫﻲ رواﺋﻊ ﻣﺼﻤﻤﺔ ﺧﺼﻴﺼًـﺎ ﻟﻠﻬﻨﺪﺳـﺔ اﻟﺒﴫـﻳﺔ وﺗﺘﻄﻠــﺐ ﺟﻬـــﺪًا ﻫـــﺎﺋﻼً ﻣـــﻦ ﻋﻠﻤـــﺎء اﻟﻔﻠـــﻚ واﳌﻬﻨﺪﺳـــﲔ واﻟﻔﻨ ـــﲔ ﻗﺒـــﻞ اﻟـــﺘﻤﻜﻦ ﻣـــﻦ اﻟﺘﻘـــﺎط اﻟﺼـــﻮر اﻷوﱃ، ﺑﺘﻤﻮﻳـــﻞ ﻣــــﻦ وزارة اﻟﻄﺎﻗــﺔ اﻷﻣﺮﻳﻜﻴـﺔ ) DOE ( ﲟﺴــﺎﻫﻤﺎت ﻣــﻦ ﴍﻛــــﺎء دوﻟﻴـــــﲔ ، ﲤــــ ﺖ ﺻـــــﻨﺎﻋﺔ ﻛـــــﺎﻣﲑا ) (DECam واﺧﺘﺒﺎرﻫــ ﺘــﱪ ﳐ ﺎ ﻓﲑﻣـــﻴﻼب اﻟﺘـــــﺎﺑﻊ ﻟـــــﻮزارة اﻟﻄﺎﻗـــــﺔ . ﻗـــــﺎم اﻟﻌﻠﻤـــــﺎء واﳌﻬﻨﺪﺳﻮن ﺑﺒﻨﺎء " ﳏﺎﰾ ﺗﻠﺴﻜﻮب " ﻧﺴـﺨﺔ ﻃﺒـــﻖ اﻷ ﺻـــﻞ ﻣــــﻦ اﻷﺟـــﺰاء اﻟﻌﻠﻮﻳــــﺔ ﻣـــﻦ ﺗﻠﺴــــﻜﻮ ب ﻓﻴﻜﺘــــﻮر إم ﺑﻼﻧﻜــــ ﻮ ﻣـــﺎ ﺳــــﻤﺢ ﺑﺒ ﺒ ] ﺒﺐ ﻣﺠﻠﺔ Astronomy ﺎﻟﻌﺮ ﺔ ٤ ٢