Coevolution of halo and quasar properties in dense environments: CARLA J1017+6116 at z = 2.8
Deep KCWI observations reveal a Lyα halo at least 128 kpc across around a radio-loud quasar in a dense environment at z = 2.8, and look at what shapes it.
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What was found
- The Lyα halo extends at least about 128 physical kpc at very faint surface brightness.
- Its kinematics are irregular, with distinct regions and asymmetries that may come from interactions between the quasar and the intracluster gas, shaped by biconical outflows and episodic activity.
- Reanalysed VLBI data show compact, variable radio emission and no extended jet, which could mean that the jet is episodic or smothered by dense gas.
- With HST imaging, one Lyα-emitting source is identified inside the halo. The analysis points to radiative feedback as the main shaping process, while jet-driven mechanical feedback looks weak or intermittent.
This summary is written for a general audience. The paper has the full details.
Cite this paper
Gallego, S. G., Mei, S., Martin, C., O’Sullivan, D., Daddi, E., Wylezalek, D., & Seymour, N. 2025, A&A, 698, A243, doi:10.1051/0004-6361/202553857
@article{gallego2025,
author = {Gallego, Sofia G. and Mei, Simona and Martin, Christopher and O’Sullivan, Donal and Daddi, Emanuele and Wylezalek, Dominika and Seymour, Nicholas},
title = {{Coevolution of halo and quasar properties in dense environments: CARLA J1017+6116 at z = 2.8}},
journal = {Astronomy & Astrophysics},
year = {2025},
volume = {698},
pages = {A243},
doi = {10.1051/0004-6361/202553857},
eprint = {2505.10094},
archivePrefix = {arXiv}
}Topics Clusters and protoclusters Quasars and AGN Circumgalactic and intergalactic gas