@misc{10481/83030,
year = {2023},
month = {5},
url = {https://hdl.handle.net/10481/83030},
abstract = {We report the discovery of a triply imaged active galactic nucleus (AGN), lensed by the galaxy cluster MACS J0035.4−2015 (z d = 0.352). The object is detected in Hubble Space Telescope imaging taken for the RELICS program. It appears to have a quasi-stellar nucleus consistent with a point-source, with a de-magnified radius of re ≲ 100 pc. The object is spectroscopically confirmed to be an AGN at z spec = 2.063 ± 0.005 showing broad rest-frame UV emission lines, and detected in both X-ray observations with Chandra and in ALCS ALMA band 6 (1.2 mm) imaging. It has a relatively faint rest-frame UV luminosity for a quasar-like object, MUV, 1450 = −19.7 ± 0.2. The object adds to just a few quasars or other X-ray sources known to be multiply lensed by a galaxy cluster. Some diffuse emission from the host galaxy is faintly seen around the nucleus, and there is a faint object nearby sharing the same multiple-imaging symmetry and geometric redshift, possibly an interacting galaxy or a star-forming knot in the host. We present an accompanying lens model, calculate the magnifications and time delays, and infer the physical properties of the source. We find the rest-frame UV continuum and emission lines to be dominated by the AGN, and the optical emission to be dominated by the host galaxy of modest stellar mass M✶ ≃ 109.2 M⊙. We also observe some variation in the AGN emission with time, which may suggest that the AGN used to be more active. This object adds a low-redshift counterpart to several relatively faint AGN recently uncovered at high redshifts with HST and JWST.},
organization = {Horizon 2020 Framework Programme
 	H2020},
organization = {Consejería de Transformación Económica, Industria, Conocimiento y Universidades
  13160, 37440},
organization = {Science and Technology Facilities Council ST/W001438/1	STFC},
organization = {European Research Council
 	ERC},
organization = {Fondo Nacional de Desarrollo Científico y Tecnológico
 1190818, 1200495, ICN12_009	FONDECYT},
organization = {Ministerio de Ciencia e Innovación
MCIN/AEI/10.13039/501100011033, P20-00334, PID2020-113689GB-I00, PID2020-114414GB-100	MICINN},
organization = {Horizon 2020
789056},
organization = {European Regional Development Fund
 	ERDF},
organization = {Junta de Andalucía
 A-FQM-510-UGR20},
publisher = {Oxford University Press},
keywords = {Gravitational lensing: strong},
keywords = {Galaxies: clusters: individual: MACS J0035.4},
keywords = {2015},
keywords = {Galaxies: nuclei},
keywords = {Quasars},
keywords = {Galaxies: Seyfert},
keywords = {Cosmology: observations},
title = {A variable active galactic nucleus at z = 2.06 triply-imaged by the galaxy cluster MACS J0035.4−2015},
doi = {10.1093/mnras/stad1321},
author = {Furtak, Lukas J. and Espada Fernández, Daniel},
}