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Title: IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS

Abstract

We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. In a previous paper, we predicted how the time delay between the bright pair of images in a 'fold' lens scales with the image separation, for smooth lens potentials. Here we show that the proportionality constant increases with the quadrupole moment of the lens potential, and depends only weakly on the position of the source along the caustic. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxies with tidal shear. We can then identify outliers as 'time delay anomalies'. We find evidence for anomalies in close image pairs in the cusp lenses RX J1131 - 1231 and B1422+231. The anomalies in RX J1131 - 1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time delay anomalies in larger-separation image pairs in the fold lenses, B1608+656 and WFI 2033 - 4723, and the cusp lens RX J0911+0551. We suggest that these anomaliesmore » are caused by some combination of substructure and a complex lens environment. Finally, to assist future monitoring campaigns we use our smooth models with shear to predict the time delays for all known four-image lenses.« less

Authors:
 [1];  [2]
  1. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 169-327, Pasadena, CA 91109-8001 (United States)
  2. Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)
Publication Date:
OSTI Identifier:
21392310
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 709; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/709/2/552; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; COSMOLOGY; GALAXIES; GRAVITATIONAL LENSES; IMAGES; MONTE CARLO METHOD; NONLUMINOUS MATTER; QUADRUPOLE MOMENTS; TIME DELAY; CALCULATION METHODS; LENSES; MATTER; SIMULATION

Citation Formats

Congdon, Arthur B, Keeton, Charles R, and Nordgren, C. Erik, E-mail: acongdon@jpl.nasa.go, E-mail: keeton@physics.rutgers.ed, E-mail: nordgren@sas.upenn.ed. IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS. United States: N. p., 2010. Web. doi:10.1088/0004-637X/709/2/552.
Congdon, Arthur B, Keeton, Charles R, & Nordgren, C. Erik, E-mail: acongdon@jpl.nasa.go, E-mail: keeton@physics.rutgers.ed, E-mail: nordgren@sas.upenn.ed. IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS. United States. https://doi.org/10.1088/0004-637X/709/2/552
Congdon, Arthur B, Keeton, Charles R, and Nordgren, C. Erik, E-mail: acongdon@jpl.nasa.go, E-mail: keeton@physics.rutgers.ed, E-mail: nordgren@sas.upenn.ed. 2010. "IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS". United States. https://doi.org/10.1088/0004-637X/709/2/552.
@article{osti_21392310,
title = {IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS},
author = {Congdon, Arthur B and Keeton, Charles R and Nordgren, C. Erik, E-mail: acongdon@jpl.nasa.go, E-mail: keeton@physics.rutgers.ed, E-mail: nordgren@sas.upenn.ed},
abstractNote = {We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. In a previous paper, we predicted how the time delay between the bright pair of images in a 'fold' lens scales with the image separation, for smooth lens potentials. Here we show that the proportionality constant increases with the quadrupole moment of the lens potential, and depends only weakly on the position of the source along the caustic. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxies with tidal shear. We can then identify outliers as 'time delay anomalies'. We find evidence for anomalies in close image pairs in the cusp lenses RX J1131 - 1231 and B1422+231. The anomalies in RX J1131 - 1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time delay anomalies in larger-separation image pairs in the fold lenses, B1608+656 and WFI 2033 - 4723, and the cusp lens RX J0911+0551. We suggest that these anomalies are caused by some combination of substructure and a complex lens environment. Finally, to assist future monitoring campaigns we use our smooth models with shear to predict the time delays for all known four-image lenses.},
doi = {10.1088/0004-637X/709/2/552},
url = {https://www.osti.gov/biblio/21392310}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 709,
place = {United States},
year = {Mon Feb 01 00:00:00 EST 2010},
month = {Mon Feb 01 00:00:00 EST 2010}
}