A Caltech Library Service

Gauging the Dark Matter Fraction in an L* S0 Galaxy at z = 0.47 Through Gravitational Lensing from Deep Hubble Space Telescope/Advanced Camera for Surveys Imaging

Covone, G. and Paolillo, M. and Napolitano, N. R. and Capaccioli, M. and Longo, G. and Kneib, J.-P. and Jullo, E. and Richard, J. and Khovanskaya, O. and Sazhin, M. and Grogin, N. A. and Schreier, E. (2009) Gauging the Dark Matter Fraction in an L* S0 Galaxy at z = 0.47 Through Gravitational Lensing from Deep Hubble Space Telescope/Advanced Camera for Surveys Imaging. Astrophysical Journal, 691 (1). pp. 531-536. ISSN 0004-637X.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We analyze a new gravitational lens OAC-GL J1223-1239, serendipitously found in a deep I814-band image of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS). The lens is an L*, edge-on S0 galaxy at zl = 0.4656. The gravitational arc has a radius of 0farcs42 sime 1.74 h^ –1 kpc. We have determined the total mass and the dark matter (DM) fraction within the Einstein radius R E as a function of the lensed source redshift, which is presently unknown. For z s ~ 1.3, which is in the middle of the redshift range plausible for the source according to some external constraints, we find the central velocity dispersion to be ~180 km s^–1. With this value, close to that obtained by means of the Faber-Jackson relation at the lens redshift, we compute a 30% DM fraction within RE (given the uncertainty in the source redshift, the allowed range for the DM fraction is 25%-35% in our lensing model). When compared with the galaxies in the local universe, the lensing galaxy OAC-GL J1223-1239 seems to fall in the transition regime between massive, DM-dominated galaxies and lower-mass, DM-deficient systems.

Item Type:Article
Related URLs:
URLURL TypeDescription
Longo, G.0000-0002-9182-8414
Kneib, J.-P.0000-0002-4616-4989
Richard, J.0000-0001-5492-1049
Additional Information:© 2009. The American Astronomical Society. Received 2007 August 28; accepted 2008 September 24; published 2009 January 15. Print publication: Issue 1 (2009 January 20). The authors thank J. M. Alcalá and M. Pannella for allowing them to use the NTT spectrum of the lensing galaxy, C. Tortora for discussions on the derivation of the stellar mass from spectroscopic data, the Director of the Space Telescope Science Institute for granting Director's Discretionary Time, and the referee for constructive comments. G.C. and N.R.N. acknowledge funding from EC through the FP6-European Reintegration Grants MERG-CT-2005-029159 and MERG-CT-2005-014774, respectively. J.P.K. acknowledge support from CNRS. O.K. acknowledges INTAS grant Ref. No. 05-109-4793. NAG acknowledges support from grant HST-GO-10715.11-A. Based on observations made with ESO Telescopes at the La Silla Observatories and the NASA/ESA Hubble Space Telescope.
Funding AgencyGrant Number
European CommunityMERG-CT-2005-029159
European CommunityMERG-CT-2005-014774
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
International Association for the promotion of cooperation with scientists from the New Independent States (NIS) (INTAS)05-109-4793
Subject Keywords:dark matter; galaxies: bulges; galaxies: structure; gravitational lensing
Issue or Number:1
Record Number:CaltechAUTHORS:COVapj09
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13113
Deposited By: Archive Administrator
Deposited On:21 Jan 2009 22:14
Last Modified:15 Nov 2019 04:40

Repository Staff Only: item control page