Free Astronomy Magazine September-October 2026 ARABIC VERSION

SEPTEMBER-OCTOBER2026        ALMA and VLA revealvast reservoir of cool molecular gas in REBELS-25 byALMAObservatory Nicolás Lira, Jill Malusky, Bárbara Ferreira stronomers have directly de- tected a vast reservoir of cool molecular gas in REBELS-25, a massivestar-forminggalaxyseen just 700 million years after the Big Bang. The discovery, made using the NSF Very Large Array (VLA) and the AtacamaLargeMillimeter/submil- limeterArray(ALMA),providesa raredirectmeasurementofthestar- formingfuelavailabletoagalaxyin theearlyuniverse. REBELS-25 is observed at a cosmic distance so vast that its light has been stretched – or redshifted – by the expansion of the universe to a redshiftofz=7.31.Astronomerssee the galaxy as it was roughly 13 bil-lion years ago, during the Epoch of Reionization—theperiodwhenthe first stars and galaxies were trans- formingtheyounguniverse,just5% ofitscurrentage.Galaxiesgrowby turninggasintostars,andmolecular gas is the primary raw material for thatprocess.Untilnow,astronomers had strong indirect evidence that some early, massive galaxies con- tained large gas supplies, but di- rectlydetectingthismaterialatsuch early cosmic times has been ex- tremely difficult. The team, led by Karin Cescon of Leiden University, used deep VLA observations to search for faint ra- dioemissionfromcarbonmonoxide, اﻛﺘﺸﺎفﺧﺰانﻫﺎﺋﻞ ﻣﻦ اﻟﻐﺎز اﻟ ﺎرد ﻓﻲﻣﺠ اﻟـﺠﺰ ﺮة REBELS-25 : ﻘﻠﻢ ﻧﻴ ﻮﻻس ﻟ ا، ﺟﻴﻞ ﻣﺎﻟﻮﺳﻜﻲ، ﺎر ﺮا ﻓ ﺮا ﻣﺮﺻﺪ أﻟﻤﺎ ﺗﻤﻜـﻦ ﻋﻠﻤﺎء اﻟﻔﻠﻚ ﻣﻦ رﺻﺪ ﺧﺰان ﻫﺎﺋﻞ ﻣﻦ اﻟﻐﺎ ز اﻟﺠﺰﻳﺌﻲ اﻟﺒﺎرد ﰲ REBELS-25 وﻫـﻲ ﻣﺠﺮة ﺿﺨﻤﺔ ﺗﺸﻬﺪ ﺗﻜﻮ ﻳﻦ ﻧﺸـﻂ ﻟﻠﻨﺠـﻮم ﺗُﺮى ﻛﻤﺎ ﻛﺎﻧﺖ ﺑﻌﺪ 700 ﻣ ﻠﻴﻮن ﺳـﻨﺔ ﻓﻘـﻂ ﻣﻦ اﻻﻧﻔﺠﺎر اﻟﻌﻈﻴﻢ وﻳﻮﻓﺮ ﻫـﺬا اﻻﻛﺘﺸـﺎف اﻟﺬي ﺗﺤﻘﻖ ﺑﺎﺳﺘﺨﺪام ﻣﺼﻔﻮﻓ ﺔ ﻛﺎرل ﺟـﻲ ﺟﺎﻧﺴﻜﻲ اﻟﻜﺒ ة ﺟـﺪاً وﻣﺼـﻔﻮﻓﺔ أﺗﺎﻛﺎﻣـﺎ ﻠا ﻴﻤﱰﻳﺔ دون ا ﻠﻴﻤﱰﻳﺔ اﻟﻜﺒ ة أ ﺎ) ﺎً ﻗﻴﺎﺳ ( اً ﻣﺒﺎﴍ اً وﻧﺎدر ﻟﻠﻮﻗﻮد ا ﺘﺎح ﻟﺘﻜﻮﻳﻦ اﻟﻨﺠـﻮم ﰲ ﻣﺠﺮة ﻣﻦ اﻟﻜـﻮن ا ﺒﻜـﺮ . ﺗُﺮﺻـﺪ ﻣﺠـﺮة REBELS-25 ﻋﲆ ﻣﺴـﺎﻓﺔ ﻛﻮﻧﻴـﺔ ﻫﺎﺋﻠـﺔ، ﺑﺤﻴﺚ ﺗﻤﺪد ﺿﻮءﻫﺎ – أو اﻧﺰاح ﻧﺤﻮ اﻷﺣﻤﺮ – ﻧﺘﻴﺠﺔ ﺗﻤﺪد اﻟﻜﻮن إﱃ اﻧﺰﻳﺎح أﺣﻤﺮ ﻣﻘﺪاره z REBELS-25 ﻋـﲆ ﻣﺴـﺎﻓﺔ ﻛﻮﻧﻴــﺔ ﻫﺎﺋ ﻠـﺔ ﺑﺤﻴﺚ ﺗﻤﺪد ﺿﻮءﻫﺎ أو اﻧـﺰاح ﻧﺤـﻮ اﻷﺣﻤـﺮ وذﻟﻚ ﻧﺘﻴﺠﺔ ﺗﻤﺪد اﻟﻜـﻮن إﱃ اﻧﺰﻳـﺎح أﺣﻤـﺮ ﻣﻘﺪاره z = 7.31 وﻳﺮى ﻋﻠﻤـﺎء اﻟﻔﻠـﻚ ﻫـﺬه ا ﺠﺮة ﻛﻤﺎ ﻛﺎﻧﺖ ﻗﺒﻞ ﻧﺤـﻮ 13 ﻣﻠﻴـﺎر ﺳـﻨﺔ ﺧﻼل ﺣﻘﺒﺔ إﻋﺎدة اﻟﺘﺄﻳﻦ وﻫﻲ اﻟﻔـﱰة اﻟﺘـﻲ ﻛﺎﻧﺖ ﻓﻴﻬـﺎ اﻟﻨﺠـﻮم وا ﺠـﺮات اﻷوﱃ ﺗﺤـﻮل اﻟﻜﻮن اﻟﻔﺘﻲ ﻋﻨﺪﻣﺎ ﻟﻢ ﻳﻜـﻦ ﻋﻤـ ﺮه ﻳﺘﺠـﺎوز 5 % ﻣﻦ ﻋﻤﺮه اﻟﺤﺎﱄ ﺗﻨﻤ . ﻮ ا ﺠﺮات ﺑﺘﺤﻮﻳـﻞ اﻟﻐﺎز إﱃ ﻧﺠﻮم وﻳ ﻌﺪ اﻟﻐـﺎز اﻟﺠﺰﻳﺌـﻲ ا ـﺎدة اﻟﺨﺎم اﻷﺳﺎﺳﻴﺔ ﻟﻬﺬه اﻟﻌﻤﻠﻴـﺔ . وﺣﺘـﻰ اﻵن، اﻣﺘﻠﻚ ﻋﻠﻤﺎء اﻟﻔﻠﻚ أدﻟﺔ ﻏـ ﻣﺒـﺎﴍة ﻗﻮﻳـﺔ اﻟﺨﺎم اﻷﺳﺎﺳﻴﺔ ﻟﻬـﺬه اﻟﻌﻤﻠﻴـﺔ وﺣﺘـﻰ اﻵن اﻣﺘﻠﻚ ﻋﻠﻤﺎء اﻟﻔﻠﻚ أدﻟﺔ ﻏـ ﻣﺒـﺎﴍة ﻗﻮﻳـﺔ ﻋـﲆ أن ﺑﻌــﺾ ا ﺠــﺮات اﻟﻀـﺨﻤﺔ ا ﺒﻜـﺮة اﺣﺘﻮت ﻋﲆ ﻛﻤﻴﺎت ﻛﺒـ ة ﻣـﻦ اﻟﻐـﺎز إﻻ أن اﻟﺮﺻﺪ ا ﺒﺎﴍ ﻟﻬﺬه ا ﺎدة ﰲ ﻣﺜﻞ ﻫﺬه اﻷزﻣﻨﺔ اﻟﻜ ﻮﻧﻴﺔ ا ﺒﻜﺮة ﻛﺎن ﺑﺎﻟﻎ اﻟﺼﻌﻮﺑﺔ . اﺳﺘﺨﺪم اﻟﻔﺮﻳﻖ ﺑﻘﻴ ﺎدة ﻛﺎرﻳﻦ ﺳﻴﺴﻜﻮن ﻣﻦ ﺟﺎﻣﻌــﺔ ﻻﻳــﺪن أرﺻـﺎد اً ﻋﻤﻴﻘـﺔ ﺑﻮاﺳـﻄﺔ ﻣﺼﻔﻮﻓ ﺔ ﻛﺎرل ﺟﻲ ﺟﺎﻧﺴﻜﻲ اﻟﻜﺒـ ة ﺟـﺪاً ﻟﻠﺒﺤﺚ ﻋﻦ اﻧﺒﻌﺎﺛﺎت رادﻳﻮﻳﺔ ﺧﺎﻓﺘﺔ ﻣـﻦ أول أﻛﺴﻴﺪ اﻟﻜﺮﺑﻮن )CO( ، وﻫﻮ ﺟﺰيء ﻳُﺴﺘﺨﺪم ﻋﲆ ﻧﻄـﺎق واﺳـﻊ ﻟﺘﺘﺒـﻊ اﻟﻐـﺎز اﻟ . ﺠﺰﻳﺌـﻲ - ﺳﺒﺘﻤﺒﺮ ﺃﻛﺘﻮﺑﺮ 2 0 2 6