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dc.contributor.authorCain, Benjamin
dc.contributor.authorBautz, Marshall W.
dc.contributor.authorSchechter, Paul L.
dc.date.accessioned2012-08-06T14:51:29Z
dc.date.available2012-08-06T14:51:29Z
dc.date.issued2011-07
dc.date.submitted2011-02
dc.identifier.issn0004-637X
dc.identifier.issn1538-4357
dc.identifier.urihttp://hdl.handle.net/1721.1/71982
dc.description.abstractMeasuring dark matter substructure within galaxy cluster halos is a fundamental probe of the ΛCDM model of structure formation. Gravitational lensing is a technique for measuring the total mass distribution which is independent of the nature of the gravitating matter, making it a vital tool for studying these dark-matter-dominated objects. We present a new method for measuring weak gravitational lensing flexion fields, the gradients of the lensing shear field, to measure mass distributions on small angular scales. While previously published methods for measuring flexion focus on measuring derived properties of the lensed images, such as shapelet coefficients or surface brightness moments, our method instead fits a mass-sheet transformation invariant Analytic Image Model (AIM) to each galaxy image. This simple parametric model traces the distortion of lensed image isophotes and constrains the flexion fields. We test the AIM method using simulated data images with realistic noise and a variety of unlensed image properties, and show that it successfully reproduces the input flexion fields. We also apply the AIM method for flexion measurement to Hubble Space Telescope observations of A1689 and detect mass structure in the cluster using flexion measured with this method. We also estimate the scatter in the measured flexion fields due to the unlensed shape of the background galaxies and find values consistent with previous estimates.en_US
dc.description.sponsorshipUnited States. National Aeronautics and Space Administration (SAO Award Number 2834-MIT-SAO-4018)en_US
dc.description.sponsorshipSpace Telescope Science Institute (STScI) (grant HST-GO-11099)en_US
dc.language.isoen_US
dc.publisherIOP Publishingen_US
dc.relation.isversionofhttp://dx.doi.org/10.1088/0004-637x/736/1/43en_US
dc.rightsCreative Commons Attribution-Noncommercial-Share Alike 3.0en_US
dc.rights.urihttp://creativecommons.org/licenses/by-nc-sa/3.0/en_US
dc.sourceProf. Schechter via Mat Willmotten_US
dc.titleMeasuring Gravitational Lensing Flexion in A1689 Using an Analytic Image Modelen_US
dc.typeArticleen_US
dc.identifier.citationCain, Benjamin, Paul L. Schechter, and M.W. Bautz. “MEASURING GRAVITATIONAL LENSING FLEXION IN A1689 USING AN ANALYTIC IMAGE MODEL.” The Astrophysical Journal 736.1 (2011): 43.en_US
dc.contributor.departmentKavli Institute for Astrophysics and Space Researchen_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Physicsen_US
dc.contributor.approverSchechter, Paul L.
dc.contributor.mitauthorSchechter, Paul L.
dc.contributor.mitauthorBautz, Marshall W.
dc.relation.journalAstrophysical Journalen_US
dc.eprint.versionAuthor's final manuscripten_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsCain, Benjamin; Schechter, Paul L.; Bautz, M.W.en
dc.identifier.orcidhttps://orcid.org/0000-0002-5665-4172
dc.identifier.orcidhttps://orcid.org/0000-0002-1379-4482
mit.licenseOPEN_ACCESS_POLICYen_US


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