Results 31 to 40 of about 18,849 (212)
Redshifts and lens profile for the double quasar QJ 0158-4325 [PDF]
Astronomy & Astrophysics, 2009 Research Note, Accepted for publication in A& ...
Faure C. +7 more
openaire +3 more sources
Discovery of Radio Emission from the Quasar SDSS J1536+0441, a Candidate Binary Black-Hole System
, 2009 The radio-quiet quasar SDSS J1536+0441 shows two broad-line emission systems that Boroson & Lauer interpret as a candidate binary black-hole system with a separation of 0.1 pc (0.02 mas). From new VLA imaging at 8.5 GHz, two faint sources, separated by 0.
A. Laor +15 more
core +1 more source
A Left and Right Truncated Schechter Luminosity Function for Quasars
Galaxies, 2017 The luminosity function for quasars (QSOs) is usually fitted by a Schechter function. The dependence of the number of quasars on the redshift, both in the low and high luminosity regions, requires the inclusion of a lower and upper boundary in the ...
Lorenzo Zaninetti
doaj +1 more source
, 2010 We present the second report of our systematic search for strongly lensed quasars from the data of the Sloan Digital Sky Survey (SDSS). From extensive follow-up observations of 136 candidate objects, we find 36 lenses in the full sample of 77,429 ...
Abazajian +97 more
core +1 more source
Clustering on very small scales from a large sample of confirmed quasar pairs: Does quasar clustering track from Mpc to kpc scales? [PDF]
, 2017 We present the most precise estimate to date of the clustering of quasars on very small scales, based on a sample of 47 binary quasars with magnitudes of ...
Djorgovski, S. G. +6 more
core +3 more sources
A Close-Separation Double Quasar Lensed by a Gas-rich Galaxy [PDF]
The Astronomical Journal, 2000 In the course of a Cycle 8 snapshot survey, we have discovered that the z=1.565 quasar HE 0512-3329 is a double with image separation 0.644", almost certainly due to gravitational lensing. The two components differ in brightness by only 0.4 magnitudes and a high signal-to-noise ground-based composite optical spectrum shows no trace of any stellar ...
Gregg, Michael D. +7 more
openaire +2 more sources
The double quasar Q2138-431: detection of a lensing galaxy [PDF]
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT This paper reviews the question of whether the wide separation double quasar Q2138-431 is a gravitational lens. From early work, the two quasar images are known to have almost identical spectra and redshifts, but no lensing galaxy has so far been detected.
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Some Consequences of the Baryonic Dark Matter Population
, 2004 Microlensed double-image quasars have sent a consistent message that the baryonic dark matter consists of a population of free-roaming planet mass objects, as summarized previously.
Schild, Rudolph E.
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The Sloan Digital Sky Survey Quasar Lens Search. I. Candidate Selection Algorithm [PDF]
, 2006 We present an algorithm for selecting an uniform sample of gravitationally lensed quasar candidates from low-redshift (0 ...
Bartosz Pindor +13 more
core +2 more sources
Relativistic Beaming and the Nuclei of Double-lobed Radio Quasars [PDF]
Symposium - International Astronomical Union, 1988 We have defined a complete sample of double-lobed 3CR quasars with minimal orientation bias. Properties of these objects on the >kpc scale are consistent with the simple beaming model for their nuclei. VLBI maps of six nuclei reveal “core-jet” structures.
D. H. Hough, A. C. S. Readhead
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