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Title: STRONGLY LENSED JETS, TIME DELAYS, AND THE VALUE OF H {sub 0}

In principle, the most straightforward method of estimating the Hubble constant relies on time delays between mirage images of strongly lensed sources. It is a puzzle, then, that the values of H {sub 0} obtained with this method span a range from ∼50-100 km s{sup –1}Mpc{sup –1}. Quasars monitored to measure these time delays are multi-component objects. The variability may arise from different components of the quasar or may even originate from a jet. Misidentifying a variable-emitting region in a jet with emission from the core region may introduce an error in the Hubble constant derived from a time delay. Here, we investigate the complex structure of the sources as the underlying physical explanation of the wide spread in values of the Hubble constant based on gravitational lensing. Our Monte Carlo simulations demonstrate that the derived value of the Hubble constant is very sensitive to the offset between the center of the emission and the center of the variable emitting region. Therefore, we propose using the value of H {sub 0} known from other techniques to spatially resolve the origin of the variable emission once the time delay is measured. We particularly advocate this method for gamma-ray astronomy, where themore » angular resolution of detectors reaches approximately 0.°1; lensed blazars offer the only route for identify the origin of gamma-ray flares. Large future samples of gravitationally lensed sources identified with Euclid, SKA, and LSST will enable a statistical determination of H {sub 0}.« less
Authors:
; ;  [1] ;  [2]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-20, Cambridge, MA 02138 (United States)
  2. Department of Physics, Brown University, Box 1843, Providence, RI 02912 (United States)
Publication Date:
OSTI Identifier:
22364537
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; COMPUTERIZED SIMULATION; GALAXIES; GAMMA ASTRONOMY; GAMMA RADIATION; GRAVITATIONAL LENSES; IMAGES; JETS; MONTE CARLO METHOD; ORIGIN; QUASARS; RESOLUTION; STELLAR FLARES; TIME DELAY