THE DARK-MATTER FRACTION IN THE ELLIPTICAL GALAXY LENSING THE QUASAR PG 1115+080
Name
Pooley_etal_2009.pdf
Size
519.53 KB
Format
Adobe PDF
Checksum (MD5)
ff44feb8aeabb02f1450bbefaa5e61c3
Author(s)
Pooley, D.
Blackburne, Jeffrey A.
Schechter, Paul L.
Wambsganss, J.
Rappaport, Saul A
Schwab, J.
Date Issued
May 2009
Journal
Astrophysical Journal
Publisher
American Astronomical Society
Citation
Pooley, D. et al. “THE DARK-MATTER FRACTION IN THE ELLIPTICAL GALAXY LENSING THE QUASAR PG 1115+080.” The Astrophysical Journal 697.2 (2009): 1892. © 2009 The American Astronomical Society
Version
Final published version
Abstract
We determine the most likely dark-matter fraction in the elliptical galaxy quadruply lensing the quasar PG 1115+080 based on analyses of the X-ray fluxes of the individual images in 2000 and 2008. Between the two epochs, the A[subscript 2] image of PG 1115+080 brightened relative to the other images by a factor of 6 in X-rays. We argue that the A[subscript 2] image had been highly demagnified in 2000 by stellar microlensing in the intervening galaxy and has recently crossed a caustic, thereby creating a new pair of microimages and brightening in the process. Over the same period, the A[subscript 2] image has brightened by a factor of only 1.2 in the optical. The most likely ratio of smooth material (dark matter) to clumpy material (stars) in the lensing galaxy to explain the observations is ~90% of the matter in a smooth dark-matter component and ~10% in stars.
MIT Department
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
http://dx.doi.org/10.1088/0004-637X/697/2/1892
