%0 Generic %1 ostrovski2016j23255229 %A Ostrovski, Fernanda %A McMahon, Richard G. %A Connolly, Andrew J. %A Lemon, Cameron A. %A Auger, Matthew W. %A Banerji, Manda %A Hung, Johnathan M. %A Koposov, Sergey E. %A Lidman, Christopher E. %A Reed, Sophie L. %A Allam, Sahar %A Benoit-Lévy, Aurélien %A Bertin, Emmanuel %A Brooks, David %A Buckley-Geer, Elizabeth %A Rosell, Aurelio Carnero %A Kind, Matias Carrasco %A Carretero, Jorge %A Cunha, Carlos E. %A da Costa, Luiz N. %A Desai, Shantanu %A Diehl, H. Thomas %A Dietrich, Jörg P. %A Evrard, August E. %A Finley, David A. %A Flaugher, Brenna %A Fosalba, Pablo %A Frieman, Josh %A Gerdes, David W. %A Goldstein, Daniel A. %A Gruen, Daniel %A Gruendl, Robert A. %A Gutierrez, Gaston %A Honscheid, Klaus %A James, David J. %A Kuehn, Kyler %A Kuropatkin, Nikolay %A Lima, Marcos %A Lin, Huan %A Maia, Marcio A. G. %A Marshall, Jennifer L. %A Martini, Paul %A Melchior, Peter %A Miquel, Ramon %A Ogando, Ricardo %A Malagón, Andrés Plazas %A Reil, Kevin %A Romer, Kathy %A Sanchez, Eusebio %A Santiago, Basilio %A Scarpine, Vic %A Sevilla-Noarbe, Ignacio %A Soares-Santos, Marcelle %A Sobreira, Flavia %A Suchyta, Eric %A Tarle, Gregory %A Thomas, Daniel %A Tucker, Douglas L. %A Walker, Alistair R. %D 2016 %K gravitational lensed quasar %T VDES J2325-5229 a z=2.7 gravitationally lensed quasar discovered using morphology independent supervised machine learning %U http://arxiv.org/abs/1607.01391 %X We present the discovery and preliminary characterization of a gravitationally lensed quasar with a source redshift $z_s=2.74$ and image separation of $2.9"$ lensed by a foreground $z_l=0.40$ elliptical galaxy. Since the images of gravitationally lensed quasars are the superposition of multiple point sources and a foreground lensing galaxy, we have developed a morphology independent multi-wavelength approach to the photometric selection of lensed quasar candidates based on Gaussian Mixture Models (GMM) supervised machine learning. Using this technique and $gi$ multicolour photometric observations from the Dark Energy Survey (DES), near IR $JK$ photometry from the VISTA Hemisphere Survey (VHS) and WISE mid IR photometry, we have identified a candidate system with two catalogue components with $i_AB=18.61$ and $i_AB=20.44$ comprised of an elliptical galaxy and two blue point sources. Spectroscopic follow-up with NTT and the use of an archival AAT spectrum show that the point sources can be identified as a lensed quasar with an emission line redshift of $z=2.739\pm0.003$ and a foreground early type galaxy with $z=0.400\pm0.002$. We model the system as a single isothermal ellipsoid and find the Einstein radius $þeta_E 1.47"$, enclosed mass $M_enc 4 10^11$M$_ødot$ and a time delay of $\sim$52 days. The relatively wide separation, month scale time delay duration and high redshift make this an ideal system for constraining the expansion rate beyond a redshift of 1.

@misc{ostrovski2016j23255229, abstract = {We present the discovery and preliminary characterization of a gravitationally lensed quasar with a source redshift $z_{s}=2.74$ and image separation of $2.9"$ lensed by a foreground $z_{l}=0.40$ elliptical galaxy. Since the images of gravitationally lensed quasars are the superposition of multiple point sources and a foreground lensing galaxy, we have developed a morphology independent multi-wavelength approach to the photometric selection of lensed quasar candidates based on Gaussian Mixture Models (GMM) supervised machine learning. Using this technique and $gi$ multicolour photometric observations from the Dark Energy Survey (DES), near IR $JK$ photometry from the VISTA Hemisphere Survey (VHS) and WISE mid IR photometry, we have identified a candidate system with two catalogue components with $i_{AB}=18.61$ and $i_{AB}=20.44$ comprised of an elliptical galaxy and two blue point sources. Spectroscopic follow-up with NTT and the use of an archival AAT spectrum show that the point sources can be identified as a lensed quasar with an emission line redshift of $z=2.739\pm0.003$ and a foreground early type galaxy with $z=0.400\pm0.002$. We model the system as a single isothermal ellipsoid and find the Einstein radius $\theta_E \sim 1.47"$, enclosed mass $M_{enc} \sim 4 \times 10^{11}$M$_{\odot}$ and a time delay of $\sim$52 days. The relatively wide separation, month scale time delay duration and high redshift make this an ideal system for constraining the expansion rate beyond a redshift of 1.}, added-at = {2016-07-07T09:35:14.000+0200}, author = {Ostrovski, Fernanda and McMahon, Richard G. and Connolly, Andrew J. and Lemon, Cameron A. and Auger, Matthew W. and Banerji, Manda and Hung, Johnathan M. and Koposov, Sergey E. and Lidman, Christopher E. and Reed, Sophie L. and Allam, Sahar and Benoit-Lévy, Aurélien and Bertin, Emmanuel and Brooks, David and Buckley-Geer, Elizabeth and Rosell, Aurelio Carnero and Kind, Matias Carrasco and Carretero, Jorge and Cunha, Carlos E. and da Costa, Luiz N. and Desai, Shantanu and Diehl, H. Thomas and Dietrich, Jörg P. and Evrard, August E. and Finley, David A. and Flaugher, Brenna and Fosalba, Pablo and Frieman, Josh and Gerdes, David W. and Goldstein, Daniel A. and Gruen, Daniel and Gruendl, Robert A. and Gutierrez, Gaston and Honscheid, Klaus and James, David J. and Kuehn, Kyler and Kuropatkin, Nikolay and Lima, Marcos and Lin, Huan and Maia, Marcio A. G. and Marshall, Jennifer L. and Martini, Paul and Melchior, Peter and Miquel, Ramon and Ogando, Ricardo and Malagón, Andrés Plazas and Reil, Kevin and Romer, Kathy and Sanchez, Eusebio and Santiago, Basilio and Scarpine, Vic and Sevilla-Noarbe, Ignacio and Soares-Santos, Marcelle and Sobreira, Flavia and Suchyta, Eric and Tarle, Gregory and Thomas, Daniel and Tucker, Douglas L. and Walker, Alistair R.}, biburl = {https://www.bibsonomy.org/bibtex/26a5e5294895342f90a01ad8f306e4628/miki}, description = {[1607.01391] VDES J2325-5229 a z=2.7 gravitationally lensed quasar discovered using morphology independent supervised machine learning}, interhash = {d1b23abe9748079d29f6df0d79361716}, intrahash = {6a5e5294895342f90a01ad8f306e4628}, keywords = {gravitational lensed quasar}, note = {cite arxiv:1607.01391Comment: 11 pages, 7 figures, 7 tables, MNRAS submitted}, timestamp = {2016-07-07T09:35:14.000+0200}, title = {VDES J2325-5229 a z=2.7 gravitationally lensed quasar discovered using morphology independent supervised machine learning}, url = {http://arxiv.org/abs/1607.01391}, year = 2016 }