A Caltech Library Service

LBQS 1429-0053: A binary quasar rather than a lensed quasar

Faure, C. and Alloin, D. and Gras, S. and Courbin, F. and Kneib, J.-P. and Hudelot, P. (2003) LBQS 1429-0053: A binary quasar rather than a lensed quasar. Astronomy & Astrophysics, 405 (2). pp. 415-424. ISSN 0004-6361. doi:10.1051/0004-6361:20030614.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


Very deep ESO/VLT FORS1 and ISAAC images, as well as HST NICMOS2 data are used to infer the nature of the quasar pair LBQS 1429-0053 A and B, either a binary quasar or a doubly-imaged lensed quasar. Direct search of a putative lensing galaxy is unsuccessful down to R = 27, J = 24, K s = 22.5 and H = 22.5. Moreover, no galaxy overdensity close to the quasar pair is found. A weak shear analysis of the FORS1 R-band 6.8´ x 6.8´ field also fails at detecting any concentration of dark matter more massive than σ = 500 km s^(-1) and weakens the hypothesis of a dark lens. The only sign of a possible lens consists in a group of 5 objects having colors consistent with galaxies at z ~ 1, within a radius of 5" from the quasar pair. Considering this group as the lensing potential does not allow to reproduce the image position and flux ratio of LBQS 1429-0053 A and B. Our deep R-band image shows a blue, previously unknown, extended object at the position of LBQS 1429-0053 A, which is consistent with either being the lensed quasar A host, or being an intervening galaxy at lower redshift. Unless future very deep optical images demonstrate that this object is actually the lensed host of LBQS 1429-0053, we conclude that there is very little evidence for LBQS 1429-0053 being lensed. Therefore, we are led to declare LBQS 1429-0053 A and B a genuine binary quasar.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Kneib, J.-P.0000-0002-4616-4989
Additional Information:© 2003 ESO. Received 20 December 2002. Accepted 27 March 2003. We acknowledge the guidance of Andreas Jaunsen in the NICMOS2 data reduction. Micol Bolzonella provided help in the application of the Hyperz software to the present dataset. We are indebted to an anonymous referee for interesting comments. The HST data used in this paper were obtained by the "CfA Arizona Space Telescope LEns Survey'' (CASTLES) collaboration (PI: E. Falco). Cécile Faure acknowledges support from an ESO studentship in Santiago. Frédéric Courbin is supported by Marie Curie grant MCFI-2001-00242. The collaborative grant ECOS/CONICYT CU00U005 between Chile and France is also gratefully acknowledged. Jean-Paul Kneib thanks CNRS for support as well as the ESO Chile visitor program.
Funding AgencyGrant Number
European Southern Observatory (ESO)UNSPECIFIED
Marie Curie FellowshipMCFI-2001-00242
Comisión Nacional de Investigación Científica y Tecnológica (CONICYT)ECOS/CONICYT CU00U005
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Subject Keywords:galaxies: clusters: general - gravitational lensing - quasar: individual: LBQS 1429-0053
Issue or Number:2
Record Number:CaltechAUTHORS:20180309-092924651
Persistent URL:
Official Citation:LBQS 1429-0053: A binary quasar rather than a lensed quasar C. Faure, D. Alloin, S. Gras, F. Courbin, J.-P. Kneib and P. Hudelot A&A, 405 2 (2003) 415-424 DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:85224
Deposited By: Ruth Sustaita
Deposited On:09 Mar 2018 17:49
Last Modified:15 Nov 2021 20:26

Repository Staff Only: item control page