TY  - JOUR
A1  - Husemann, Bernd
A1  - Worseck, Gabor
A1  - Battaia, Fabrizio Arrigoni
A1  - Shanks, T.
T1  - Discovery of a dual AGN at z similar or equal to 3.3 with 20 kpc separation
JF  - Astronomy and astrophysics : an international weekly journal
N2  - A prediction of the current paradigm of the hierarchical assembly of galaxies is the presence of supermassive dual black holes at separations of a few kpc or less. In this context, we report the detection of a narrow-line emitter within the extended Ly alpha nebula (similar to 120 kpc diameter) of the luminous radio-quiet quasi-stellar object (QSO) LBQS 0302 0019 at z = 3 : 286. We identify several high-ionization narrow emission lines (He II, C IV, C III) associated with this point-like source, which we have named "Jil", which is only similar to 20 kpc (2 : 0 0 9) away from the QSO in projection. Emission-line diagnostics confirm that the source is likely powered by photoionization of an obscured active galactic nucleus (AGN) three orders of magnitude fainter than the QSO. The system represents the tightest unobscured/obscured dual AGN currently known at z > 3, highlighting the power of MUSE to detect these elusive systems.
KW  - Techniques: imaging spectroscopy
KW  - Ultraviolet: ISM
KW  - galaxies: high-redshift
KW  - quasars: individual: LBQS 0302-0019
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201732457
SN  - 1432-0746
VL  - 610
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Husemann, Bernd
A1  - Bielby, R.
A1  - Jahnke, K.
A1  - Arrigoni-Battaia, F.
A1  - Worseck, Gabor
A1  - Shanks, T.
A1  - Wardlow, J.
A1  - Scholtz, J.
T1  - Cosmic dance at z similar to 3
BT  - Detecting the host galaxies of the dual AGN system LBQS 0302-0019 and Jil with HAWK-I plus GRAAL
JF  - Astronomy and astrophysics : an international weekly journal
N2  - We recently discovered that the luminous radio-quiet (QSO) LBQS 0302-0019 at z=3.286 is likely accompanied by an obscured AGN at 20 kpc projected distance, which we dubbed Jil. It represents the tightest candidate obscured/unobscured dual AGN system at z >3. To verify the dual AGN scenario we obtained deep K-s band (rest-frame V band) imaging with the VLT/HAWK-I+GRAAL instrument at 0 '.4 resolution during science verification in January 2018. Indeed, we detect the individual host galaxies of the QSO and Jil with estimated stellar masses of log(M-*/M-circle dot)=11.4 +/- 0.5 and log(M-*/M-circle dot)=10.9 +/- 0.5, respectively. Near-IR spectra obtained with VLT-KMOS reveal a clear [O-III] lambda 5007 line detection at the location of Jil which does not contribute significantly to the Ks band flux. Both observations therefore corroborate the dual AGN scenario. A comparison to Illustris cosmological simulations suggests a parent halo mass of log(M-halo/M-*)=13.2 +/- 0.5 for this interacting galaxy system, corresponding to a very massive dark matter halo at that epoch.
KW  - Galaxies: interactions
KW  - Galaxies: high-redshift
KW  - large-scale structure of Universe
KW  - instrumentation: adaptive optics
KW  - quasars: individual: LBQS 0302-0018
Y1  - 2018
U6  - https://doi.org/10.1051/0004-6361/201833363
SN  - 1432-0746
VL  - 614
PB  - EDP Sciences
CY  - Les Ulis
ER  -