A Caltech Library Service

A Detection of Weak-lensing Magnification Using Galaxy Sizes and Magnitudes

Schmidt, Fabian and Leauthaud, Alexie and Massey, Richard and Rhodes, Jason and George, Matthew R. and Koekemoer, Anton M. and Finoguenov, Alexis and Tanaka, Masayuki (2012) A Detection of Weak-lensing Magnification Using Galaxy Sizes and Magnitudes. Astrophysical Journal Letters, 744 (2). L22. ISSN 2041-8205. doi:10.1088/2041-8205/744/2/L22.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


Weak lensing is commonly measured using shear through galaxy ellipticities or using the effect of magnification bias on galaxy number densities. Here, we report on the first detection of weak-lensing magnification with a new, independent technique using the distribution of galaxy sizes and magnitudes. These data come for free in galaxy surveys designed for measuring shear. We present the magnification estimator and apply it to an X-ray-selected sample of galaxy groups in the COSMOS Hubble Space Telescope survey. The measurement of the projected surface density Σ(r) is consistent with the shear measurements within the uncertainties and has roughly 40% of the signal to noise of the latter. We discuss systematic issues and challenges to realizing the potential of this new probe of weak lensing.

Item Type:Article
Related URLs:
URLURL TypeDescription
Leauthaud, Alexie0000-0002-3677-3617
Massey, Richard0000-0002-6085-3780
Rhodes, Jason0000-0002-4485-8549
Koekemoer, Anton M.0000-0002-6610-2048
Finoguenov, Alexis0000-0002-4606-5403
Tanaka, Masayuki0000-0002-5011-5178
Additional Information:© 2012 American Astronomical Society. Received 2011 August 24; accepted 2011 November 17; published 2011 December 19. We thank Jessica Ford, Hendrik Hildebrandt, Bhuvnesh Jain, Donghui Jeong, Eric Jullo, James Taylor, and Ludovic van Waerbeke for helpful discussions. F.S. is supported by the Gordon and Betty Moore Foundation. R.M. is supported by an STFC Advanced Fellowship. J.R. was supported by JPL, run by Caltech for NASA. This work was supported by World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan.
Group:Moore Center for Theoretical Cosmology and Physics
Funding AgencyGrant Number
Gordon and Betty Moore FoundationUNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Ministry of Education, Culture, Sports, Science and Technology (MEXT)UNSPECIFIED
Subject Keywords:dark matter; gravitational lensing: weak; large-scale structure of universe
Issue or Number:2
Record Number:CaltechAUTHORS:20120312-110204684
Persistent URL:
Official Citation:A Detection of Weak-lensing Magnification Using Galaxy Sizes and Magnitudes Fabian Schmidt et al. 2012 ApJ 744 L22
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29691
Deposited By: Jason Perez
Deposited On:13 Mar 2012 22:57
Last Modified:09 Nov 2021 19:28

Repository Staff Only: item control page