Determining the Hubble Constant from the Gravitational Lens PG 1115+080
نویسندگان
چکیده
منابع مشابه
The Hubble Constant from the Gravitational Lens
We present a refined gravitational lens model of the four-image lens system B1608+656 based on new and improved observational constraints: (i) the three independent time-delays and flux-ratios from Very Large Array (VLA) observations, (ii) the radio-image positions from Very Large Baseline Array (VLBA) observations, (iii) the shape of the deconvolved Einstein Ring from optical and infrared Hubb...
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There are now 10 firm time delay measurements in gravitational lenses. The physics of time delays is well understood, and the only important variable for interpreting the time delays to determine H0 is the mean surface mass density 〈κ〉 (in units of the critical density for gravitational lensing) of the lens galaxy at the radius of the lensed images. More centrally concentrated mass distribution...
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One of the main objectives of the Cosmic Lens All-Sky Survey (CLASS) collaboration has been to find gravitational lens (GL) systems at radio wavelengths that are suitable for the determination of time delays between image pairs. The survey is now near completion and at least 18 GL systems have been found. Here, I will discuss our efforts to measure time delays from several of these systems with...
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We present deep optical observations of the gravitational lens system CLASS B0218+357 from which we derive an estimate for the Hubble Constant (H0) Extensive radio observations using the VLA, MERLIN, the VLBA and VLBI have reduced the degeneracies between H0 and the mass model parameters in this lens to one involving only the position of the radioquiet lensing galaxy with respect to the lensed ...
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We present a simple mass model for the lensing galaxy in the gravitationally lensed quasar 0957+561. We represent the galaxy as a softened power-law sphere (SPLS), a generalization of the singular isothermal sphere with three parameters — ρ0, the central density, θc, the angular core radius, and η, the radial index which is defined such that mass increases as r at large radius. As in previous s...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1997
ISSN: 0004-637X,1538-4357
DOI: 10.1086/304583