Improper Motions in Lensed QSOs
نویسندگان
چکیده
منابع مشابه
Qualitative Theory for Lensed QSOs
We show that some characteristics of multiply-imaged QSO systems are very modelindependent and can be deduced accurately by simply scrutinizing the relative positions of images and galaxy-lens center. These include the time-ordering of the images, the orientation of the lens potential, and the rough morphology of any ring. Other features can differ considerably between specific models; H0 is an...
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Imaging and spectra of the lensed QSO pair 0957+561 are presented and discussed. The data are principally those from the STIS NUV MAMA, and cover rest wavelengths from 850Å to 1350Å. The QSOs are both extended over about 1 arcsec, with morphology that matches with a small rotation, and includes one feature aligned with the VLBI radio jets. This is the first evidence of lensed structure in the h...
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Observations of absorption systems in close, multiple lines of sight to gravitationally lensed QSOs can be used to infer the density fluctuations and motions of the gas clouds giving rise to the Lyman α forest phenomenon and to QSO metal absorption systems. We describe a survey of lensed QSOs with the Keck HIRES instrument and argue that one can derive limits on the frequency and impact of hydr...
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We consider the influence of (milli/micro)lensing on the spectra of lensed QSOs. We propose a method for the observational detection of microlensing in the spectra of lensed QSOs and apply it to the spectra of the three lensed QSOs (PG 1115+080, QSO 1413+117 and QSO 0957+561) observed with Hubble Space Telescope (HST). We find that the flux ratio between images A1 and A2 of PG 1115+080 is wavel...
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It is well known that improper priors in Bayesian statistics may lead to proper posterior distributions and useful inference procedures. This motivates us to give an elementary introduction to a theoretical frame for statistics that includes improper priors. Axioms that allow improper priors are given by a relaxed version of Kolmogorov’s formulation of probability theory. The theory of conditio...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1995
ISSN: 0004-6256
DOI: 10.1086/117620