Results 21 to 30 of about 81,623 (245)
Monthly Notices of the Royal Astronomical Society, 1999 Quasar pairs are either physically distinct binary quasars or the result of gravitational lensing. The majority of known pairs are in fact lenses, with a few confirmed as binaries, leaving a population of objects that have not yet been successfully classified.
Mortlock, D +2 more
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THE PROPERTIES OF QUASAR HOSTS AT THE PEAK OF THE QUASAR ACTIVITY [PDF]
The Astrophysical Journal, 2009 We present near-infrared imaging obtained with ESO VLT/ISAAC of a sample of 16 low luminosity radio-quiet quasars at the epoch around the peak of the quasar activity (2 < z < 3), aimed at investigating their host galaxies. For 11 quasars, we are able to detect the host galaxies and derive their properties, while for the other five quasars, upper ...
Kotilainen J. K. +5 more
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The Astrophysical Journal, 2002 In a survey of quasar candidates selected by matching the FIRST and 2MASS catalogs, we have found two extraordinarily red quasars. FIRST J013435.7-093102 is a 1 Jy source at z=2.216 and has B-K > 10, while FIRST J073820.1+275045 is a 2.5 mJy source at z=1.985 with B-K = 8.4.
Mark Lacy +9 more
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Symposium - International Astronomical Union, 1994 I review recent results for quasars and discuss how they are related to activity in galaxies. Topics included are studies of quasar host galaxies with HST; searches for quasars in the Hubble Deep Field; evolution of the quasar luminosity function; news highlights from astro-ph; and current observational research problems and their relation to ...
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A Hubble Diagram for Quasars [PDF]
Frontiers in Astronomy and Space Sciences, 2015 The cosmological model is at present not tested between the redshift of the farthest observed supernovae (z ~ 1.4) and that of the Cosmic Microwave Background (z ~ 1,100). Here we introduce a new method to measure the cosmological parameters: we show that quasars can be used as "standard candles" by employing the non-linear relation between their ...
Guido Risaliti +4 more
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EXTENDED SCATTERING ENVELOPE IN THE Q2237+0305 QUASAR
Radio Physics and Radio Astronomy, 2019 Purpose: Studying the accretion disc structure in the Q2237+0305 gravitationally lensed quasar in optical wavelengths; estimation of parameters of the matter accretion regime onto a central black hole.
L. A. Berdina +2 more
doaj +1 more source
magazén, 2022 The city is a set of arbitrary visual experiences dispersed in time that must necessarily be integrated. In studying the absences, Bruno Toscano writes that “the city would appear to us in a less verisimilar facies if we resigned ourselves to consider
Farina, Arianna
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Do Quasars Lens Quasars? [PDF]
The Astrophysical Journal, 1997 If the unexpectedly high frequency of quasar pairs with very different component redshifts is due to the lensing of a population of background quasars by the foreground quasar, typical lens masses must be $\sim10^{12}M_{\sun}$ and the sum of all such quasar lenses would have to contain $\sim0.005$ times the closure density of the Universe.
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A slitless spectroscopic survey for quasars near quasars [PDF]
Astronomy & Astrophysics, 2008 18 pages, 16 figures, accepted by A&A, includes Table 2 from online material, full paper with appendices containing additional figures and tables available at http://www.aip.de/People/gworseck/qnqpaper/qnqpaper_final ...
Lutz Wisotzki +2 more
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Two Close Separation Quasar-Quasar Pairs in the Large Bright Quasar Survey [PDF]
The Astronomical Journal, 1998 Accepted for publication in the Astronomical Journal, Paper, 4 Figures + 1 ...
Margaret E. Harding +5 more
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