MUSE spectroscopy of the compact dual AGN in the z=3.273 radio-loud gravitational lens MG B2016+112
Abstract
Dual active galactic nuclei (AGN) are unique laboratories for studying how galaxy mergers trigger accretion onto supermassive black holes (SMBHs). However, at redshifts z>1, only few dual AGN are confirmed at projected separations ≳ 1 kpc for the two SMBHs. We present archival MUSE spectroscopy of the three resolved lensed images of the radio-loud system MG B2016+112. At z = 3.273 and at a projected separation of 175 pc, this the most compact confirmed dual AGN at z > 1. We detect Lyα, C IV, N V, He II, and C III] emission across images A−−C after correcting for ISM absorption at z ∼ 0. We find that the Ly α, C IV, N V lines are affected by saturated absorption at z ∼ 3.27. The He II / C III] emission-line ratios are consistent between images A and B but differ significantly from image C. We fit the C IV emission regions of images A−−C by allowing for up to two Gaussians and use broad component to place lower limits on their respective SMBH masses: ≳ 2 × 107 M⊙, ≳ 2.3 × 107 M⊙, and ≳ 1.5 × 107 M⊙. Correcting for their strong lensing magnifications suggests Eddington ratios of ≲ 0.47, 0.51, and 0.04, respectively. Together with previous VLBI and X-ray analyses, our results provide strong, independent spectroscopic evidence that MG B2016+112 hosts two AGN. Our findings motivate deep, spatially resolved near-IR spectroscopy to independently revisit our mass estimates and determine the physical conditions of the host galaxy, which has likely undergone a major merger.
Related
- Chandra X-ray Spectral Evidence of the Dual AGN Nature of the Gravitational lens MG B2016+112 at z=3.273 with 175 pc separation
- A statistical study of the environmental age of core-collapse supernovae based on VLT/MUSE integral-field-unit spectroscopy
- Ejecta clumps revealed by study of reverse-shocked ejecta through MUSE integral field spectroscopy of SNR 0509-67.5
- Broadband radio continuum and host galaxy properties of extremely inverted spectrum compact radio galaxies
- Broadband radio continuum and host galaxy properties of extremely inverted spectrum compact radio galaxies
BibTeX
@misc{huyan2026muse,
title = {{MUSE spectroscopy of the compact dual AGN in the $z=3.273$ radio-loud gravitational lens MG B2016+112}},
author = {Jianghao Huyan and Júlia M. Sisk-Reynés and Daniel A. Schwartz and Varsha P. Kulkarni and Anna Barnacka and Adi Foord and Charlotte A. Eades},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31826},
eprint = {2609.31826},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.31826},
}
RIS
TY - UNPB
TI - MUSE spectroscopy of the compact dual AGN in the z=3.273 radio-loud gravitational lens MG B2016+112
AU - Jianghao Huyan
AU - Júlia M. Sisk-Reynés
AU - Daniel A. Schwartz
AU - Varsha P. Kulkarni
AU - Anna Barnacka
AU - Adi Foord
AU - Charlotte A. Eades
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.31826
UR - https://arxiv.org/abs/2609.31826
AB - Dual active galactic nuclei (AGN) are unique laboratories for studying how galaxy mergers trigger accretion onto supermassive black holes (SMBHs). However, at redshifts z>1, only few dual AGN are confirmed at projected separations ≳ 1 kpc for the two SMBHs. We present archival MUSE spectroscopy of the three resolved lensed images of the radio-loud system MG B2016+112. At z = 3.273 and at a projected separation of 175 pc, this the most compact confirmed dual AGN at z > 1. We detect Lyα, C IV, N V, He II, and C III] emission across images A−−C after correcting for ISM absorption at z ∼ 0. We find that the Ly α, C IV, N V lines are affected by saturated absorption at z ∼ 3.27. The He II / C III] emission-line ratios are consistent between images A and B but differ significantly from image C. We fit the C IV emission regions of images A−−C by allowing for up to two Gaussians and use broad component to place lower limits on their respective SMBH masses: ≳ 2 × 10^7 M_⊙, ≳ 2.3 × 10^7 M_⊙, and ≳ 1.5 × 10^7 M_⊙. Correcting for their strong lensing magnifications suggests Eddington ratios of ≲ 0.47, 0.51, and 0.04, respectively. Together with previous VLBI and X-ray analyses, our results provide strong, independent spectroscopic evidence that MG B2016+112 hosts two AGN. Our findings motivate deep, spatially resolved near-IR spectroscopy to independently revisit our mass estimates and determine the physical conditions of the host galaxy, which has likely undergone a major merger.
ER -