Monster Radio Jet (>66 kpc) Observed in Quasar at z ∼​​​​​ 5

Gloudemans, Anniek J.; Sweijen, Frits; Morabito, Leah K.; Farina, Emanuele Paolo; Duncan, Kenneth J.; Harikane, Yuichi; Röttgering, Huub J. A.; Saxena, Aayush; Schindler, Jan-Torge

Abstract

We present the discovery of a large extended radio jet associated with the extremely radio-loud quasar J1601+3102 at z ∼​​​​​ 5 from subarcsecond resolution imaging at 144 MHz with the International LOFAR Telescope. These large radio lobes have been argued to remain elusive at z > 4 due to energy losses in the synchrotron emitting plasma as a result of scattering of the strong cosmic microwave background at these high redshifts. Nonetheless, the 0 .′′ 3 resolution radio image of J1601+3102 reveals a northern and a southern radio lobe located at 9 and 57 kpc from the optical quasar, respectively. The measured jet size of 66 kpc makes J1601+3102 the largest extended radio jet at z > 4 to date. However, it is expected to have an even larger physical size in reality due to projection effects brought about by the viewing angle. Furthermore, we observe the rest-frame UV spectrum of J1601+3102 with Gemini/GNIRS to examine its black hole properties, which results in a mass of 4.5 × 108 M⊙ with an Eddington luminosity ratio of 0.45. The black hole mass is relatively low compared to the known high-z quasar population, which suggests that a high black hole mass is not strictly necessary to generate a powerful jet. This discovery of the first ∼​​​​​100 kpc radio jet at z > 4 shows that these objects exist despite energy losses from inverse Compton scattering and can put invaluable constraints on the formation of the first radio-loud sources in the early Universe.

Citation

Gloudemans, A. J., Sweijen, F., Morabito, L. K., Farina, E. P., Duncan, K. J., Harikane, Y., Röttgering, H. J. A., Saxena, A., & Schindler, J.-T. (2025). Monster Radio Jet (>66 kpc) Observed in Quasar at z ∼​​​​​ 5. Astrophysical Journal Letters, 980(1), Article L8. https://doi.org/10.3847/2041-8213/ad9609

• Journal Article Type: Article
• Acceptance Date: Nov 22, 2024
• Online Publication Date: Feb 6, 2025
• Publication Date: Feb 10, 2025
• Deposit Date: Feb 10, 2025
• Publicly Available Date: Feb 10, 2025
• Journal: Astrophysical Journal Letters
• Print ISSN: 2041-8205
• Electronic ISSN: 2041-8213
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 980
• Issue: 1
• Article Number: L8
• DOI: https://doi.org/10.3847/2041-8213/ad9609
• Keywords: High-redshift galaxies, Radio jets, Radio loud quasars
• Public URL: https://durham-repository.worktribe.com/output/3474940