Free Astronomy Magazine May-June 2025

49 MAY-JUNE 2025 frared Spectrograph (GNIRS), and in the optical with the Hobby Eberly Telescope, were obtained to paint a complete picture of the radio jet and the quasar producing it. These findings are crucial to gaining more insight into the timing and mecha- nisms behind the formation of the first large-scale jets in our Universe. GNIRS is mounted on the Gemini North telescope, one half of the In- ternational Gemini Observatory, funded in part by the U.S. National Science Foundation (NSF) and oper- ated by NSF NOIRlab. “We were searching for quasars with strong radio jets in the early Universe, which helps us understand how and when the first jets are formed and how they impact the evolution of galaxies,” says Anniek Gloudemans, postdoctoral research fellow at NOIRLab and lead author of the paper presenting these results in The Astrophysical Journal Letters . Determining the properties of the quasar, such as its mass and the rate at which it is consuming matter, is necessary for understanding its for- mation history. To measure these pa- rameters the team looked for a specific wavelength of light emitted by quasars known as the MgII (mag- nesium) broad emission line. Nor- mally, this signal appears in the ultraviolet wavelength range. How- ever, owing to the expansion of the Universe, which causes the light emitted by the quasar to be ‘stretched’ to longer wavelengths, the magnesium signal arrives at Earth in the near-infrared wave- length range, where it is detectable with GNIRS. The quasar, named J1601+3102, formed when the Universe was less than 1.2 billion years old — just 9% of its current age. While quasars can have masses billions of times greater than that of our Sun, this one is on the small side, weighing in at 450 million times the mass of the Sun. The double-sided jets are asymmet- rical both in brightness and the dis- tance they stretch from the quasar, indicating an extreme environment may be affecting them. “Interestingly, the quasar powering this massive radio jet does not have an extreme black hole mass com- pared to other quasars,” says Gloudemans. “This seems to indicate that you don’t necessarily need an exceptionally massive black hole or accretion rate to generate such powerful jets in the early Universe.” The previous dearth of large radio jets in the early Universe has been attributed to noise from the cosmic microwave background — the ever- present fog of microwave radiation left over from the Big Bang. This persistent background radiation normally diminishes the radio light of such distant objects. “It’s only because this object is so ex- T his artist’s illustration shows the largest radio jet ever found in the early Universe. The jet was first identified using the international Low Fre- quency Array (LOFAR) Telescope, a network of radio telescopes throughout Europe. Follow-up observations in the near-infrared with the Gemini Near- Infrared Spectrograph (GNIRS), and in the optical with the Hobby Eberly Telescope, were obtained to paint a complete picture of the radio jet and the quasar producing it. [NOIRLab/NSF/AURA/M. Garlick]